target: add generic Xtensa LX support
[fw/openocd] / src / target / xtensa / xtensa.c
index 6f9d77e6cc80993edd5172c27b70bf4a2b20183f..fe0f43882b09106299d6ad958717645d8bc5da4e 100644 (file)
@@ -2,6 +2,7 @@
 
 /***************************************************************************
  *   Generic Xtensa target API for OpenOCD                                 *
+ *   Copyright (C) 2020-2022 Cadence Design Systems, Inc.                  *
  *   Copyright (C) 2016-2019 Espressif Systems Ltd.                        *
  *   Derived from esp108.c                                                 *
  *   Author: Angus Gratton gus@projectgus.com                              *
 #include <helper/align.h>
 #include <target/register.h>
 
+#include "xtensa_chip.h"
 #include "xtensa.h"
 
-
-#define _XT_INS_FORMAT_RSR(OPCODE, SR, T) ((OPCODE)        \
-               | (((SR) & 0xFF) << 8) \
+/* Swap 4-bit Xtensa opcodes and fields */
+#define XT_NIBSWAP8(V)                                                                 \
+       ((((V) & 0x0F) << 4)                                                            \
+               | (((V) & 0xF0) >> 4))
+
+#define XT_NIBSWAP16(V)                                                                        \
+       ((((V) & 0x000F) << 12)                                                         \
+               | (((V) & 0x00F0) << 4)                                                 \
+               | (((V) & 0x0F00) >> 4)                                                 \
+               | (((V) & 0xF000) >> 12))
+
+#define XT_NIBSWAP24(V)                                                                        \
+       ((((V) & 0x00000F) << 20)                                                       \
+               | (((V) & 0x0000F0) << 12)                                              \
+               | (((V) & 0x000F00) << 4)                                               \
+               | (((V) & 0x00F000) >> 4)                                               \
+               | (((V) & 0x0F0000) >> 12)                                              \
+               | (((V) & 0xF00000) >> 20))
+
+/* _XT_INS_FORMAT_*()
+ * Instruction formatting converted from little-endian inputs
+ * and shifted to the MSB-side of DIR for BE systems.
+ */
+#define _XT_INS_FORMAT_RSR(X, OPCODE, SR, T)                   \
+       (XT_ISBE(X) ? (XT_NIBSWAP24(OPCODE)                                     \
+                       | (((T) & 0x0F) << 16)                                          \
+                       | (((SR) & 0xFF) << 8)) << 8                            \
+               : (OPCODE)                                                                              \
+               | (((SR) & 0xFF) << 8)                                                  \
                | (((T) & 0x0F) << 4))
 
-#define _XT_INS_FORMAT_RRR(OPCODE, ST, R) ((OPCODE)        \
-               | (((ST) & 0xFF) << 4) \
+#define _XT_INS_FORMAT_RRR(X, OPCODE, ST, R)                   \
+       (XT_ISBE(X) ? (XT_NIBSWAP24(OPCODE)                                     \
+                       | ((XT_NIBSWAP8((ST) & 0xFF)) << 12)            \
+                       | (((R) & 0x0F) << 8)) << 8                                     \
+               : (OPCODE)                                                                              \
+               | (((ST) & 0xFF) << 4)                                                  \
                | (((R) & 0x0F) << 12))
 
-#define _XT_INS_FORMAT_RRRN(OPCODE, S, T, IMM4) ((OPCODE)            \
-               | (((T) & 0x0F) << 4)   \
-               | (((S) & 0x0F) << 8)   \
+#define _XT_INS_FORMAT_RRRN(X, OPCODE, S, T, IMM4)             \
+       (XT_ISBE(X) ? (XT_NIBSWAP16(OPCODE)                                     \
+                       | (((T) & 0x0F) << 8)                                           \
+                       | (((S) & 0x0F) << 4)                                           \
+                       | ((IMM4) & 0x0F)) << 16                                        \
+               : (OPCODE)                                                                              \
+               | (((T) & 0x0F) << 4)                                                   \
+               | (((S) & 0x0F) << 8)                                                   \
                | (((IMM4) & 0x0F) << 12))
 
-#define _XT_INS_FORMAT_RRI8(OPCODE, R, S, T, IMM8) ((OPCODE)       \
-               | (((IMM8) & 0xFF) << 16) \
-               | (((R) & 0x0F) << 12)  \
-               | (((S) & 0x0F) << 8)   \
+#define _XT_INS_FORMAT_RRI8(X, OPCODE, R, S, T, IMM8)  \
+       (XT_ISBE(X) ? (XT_NIBSWAP24(OPCODE)                                     \
+                       | (((T) & 0x0F) << 16)                                          \
+                       | (((S) & 0x0F) << 12)                                          \
+                       | (((R) & 0x0F) << 8)                                           \
+                       | ((IMM8) & 0xFF)) << 8                                         \
+               : (OPCODE)                                                                              \
+               | (((IMM8) & 0xFF) << 16)                                               \
+               | (((R) & 0x0F) << 12)                                                  \
+               | (((S) & 0x0F) << 8)                                                   \
                | (((T) & 0x0F) << 4))
 
-#define _XT_INS_FORMAT_RRI4(OPCODE, IMM4, R, S, T) ((OPCODE) \
-               | (((IMM4) & 0x0F) << 20) \
-               | (((R) & 0x0F) << 12) \
-               | (((S) & 0x0F) << 8)   \
+#define _XT_INS_FORMAT_RRI4(X, OPCODE, IMM4, R, S, T)  \
+       (XT_ISBE(X) ? (XT_NIBSWAP24(OPCODE)                                     \
+                       | (((T) & 0x0F) << 16)                                          \
+                       | (((S) & 0x0F) << 12)                                          \
+                       | (((R) & 0x0F) << 8)) << 8                                     \
+               | ((IMM4) & 0x0F)                                                               \
+               : (OPCODE)                                                                              \
+               | (((IMM4) & 0x0F) << 20)                                               \
+               | (((R) & 0x0F) << 12)                                                  \
+               | (((S) & 0x0F) << 8)                                                   \
                | (((T) & 0x0F) << 4))
 
 /* Xtensa processor instruction opcodes
- * "Return From Debug Operation" to Normal */
-#define XT_INS_RFDO      0xf1e000
+*/
+/* "Return From Debug Operation" to Normal */
+#define XT_INS_RFDO(X) (XT_ISBE(X) ? 0x000e1f << 8 : 0xf1e000)
 /* "Return From Debug and Dispatch" - allow sw debugging stuff to take over */
-#define XT_INS_RFDD      0xf1e010
+#define XT_INS_RFDD(X) (XT_ISBE(X) ? 0x010e1f << 8 : 0xf1e010)
 
 /* Load to DDR register, increase addr register */
-#define XT_INS_LDDR32P(S) (0x0070E0 | ((S) << 8))
+#define XT_INS_LDDR32P(X, S) (XT_ISBE(X) ? (0x0E0700 | ((S) << 12)) << 8 : (0x0070E0 | ((S) << 8)))
 /* Store from DDR register, increase addr register */
-#define XT_INS_SDDR32P(S) (0x0070F0 | ((S) << 8))
-
-/* Load 32-bit Indirect from A(S) + 4 * IMM8 to A(T) */
-#define XT_INS_L32I(S, T, IMM8)  _XT_INS_FORMAT_RRI8(0x002002, 0, S, T, IMM8)
-/* Load 16-bit Unsigned from A(S) + 2 * IMM8 to A(T) */
-#define XT_INS_L16UI(S, T, IMM8) _XT_INS_FORMAT_RRI8(0x001002, 0, S, T, IMM8)
-/* Load 8-bit Unsigned from A(S) + IMM8 to A(T) */
-#define XT_INS_L8UI(S, T, IMM8)  _XT_INS_FORMAT_RRI8(0x000002, 0, S, T, IMM8)
-
-/* Store 32-bit Indirect to A(S) + 4 * IMM8 from A(T) */
-#define XT_INS_S32I(S, T, IMM8) _XT_INS_FORMAT_RRI8(0x006002, 0, S, T, IMM8)
-/* Store 16-bit to A(S) + 2 * IMM8 from A(T) */
-#define XT_INS_S16I(S, T, IMM8) _XT_INS_FORMAT_RRI8(0x005002, 0, S, T, IMM8)
-/* Store 8-bit to A(S) + IMM8 from A(T) */
-#define XT_INS_S8I(S, T, IMM8)  _XT_INS_FORMAT_RRI8(0x004002, 0, S, T, IMM8)
+#define XT_INS_SDDR32P(X, S) (XT_ISBE(X) ? (0x0F0700 | ((S) << 12)) << 8 : (0x0070F0 | ((S) << 8)))
+
+/* Load 32-bit Indirect from A(S)+4*IMM8 to A(T) */
+#define XT_INS_L32I(X, S, T, IMM8)  _XT_INS_FORMAT_RRI8(X, 0x002002, 0, S, T, IMM8)
+/* Load 16-bit Unsigned from A(S)+2*IMM8 to A(T) */
+#define XT_INS_L16UI(X, S, T, IMM8) _XT_INS_FORMAT_RRI8(X, 0x001002, 0, S, T, IMM8)
+/* Load 8-bit Unsigned from A(S)+IMM8 to A(T) */
+#define XT_INS_L8UI(X, S, T, IMM8)  _XT_INS_FORMAT_RRI8(X, 0x000002, 0, S, T, IMM8)
+
+/* Store 32-bit Indirect to A(S)+4*IMM8 from A(T) */
+#define XT_INS_S32I(X, S, T, IMM8) _XT_INS_FORMAT_RRI8(X, 0x006002, 0, S, T, IMM8)
+/* Store 16-bit to A(S)+2*IMM8 from A(T) */
+#define XT_INS_S16I(X, S, T, IMM8) _XT_INS_FORMAT_RRI8(X, 0x005002, 0, S, T, IMM8)
+/* Store 8-bit to A(S)+IMM8 from A(T) */
+#define XT_INS_S8I(X, S, T, IMM8)  _XT_INS_FORMAT_RRI8(X, 0x004002, 0, S, T, IMM8)
+
+/* Cache Instructions */
+#define XT_INS_IHI(X, S, IMM8) _XT_INS_FORMAT_RRI8(X, 0x0070E2, 0, S, 0, IMM8)
+#define XT_INS_DHWBI(X, S, IMM8) _XT_INS_FORMAT_RRI8(X, 0x007052, 0, S, 0, IMM8)
+#define XT_INS_DHWB(X, S, IMM8) _XT_INS_FORMAT_RRI8(X, 0x007042, 0, S, 0, IMM8)
+#define XT_INS_ISYNC(X) (XT_ISBE(X) ? 0x000200 << 8 : 0x002000)
+
+/* Control Instructions */
+#define XT_INS_JX(X, S) (XT_ISBE(X) ? (0x050000 | ((S) << 12)) : (0x0000a0 | ((S) << 8)))
+#define XT_INS_CALL0(X, IMM18) (XT_ISBE(X) ? (0x500000 | ((IMM18) & 0x3ffff)) : (0x000005 | (((IMM18) & 0x3ffff) << 6)))
 
 /* Read Special Register */
-#define XT_INS_RSR(SR, T) _XT_INS_FORMAT_RSR(0x030000, SR, T)
+#define XT_INS_RSR(X, SR, T) _XT_INS_FORMAT_RSR(X, 0x030000, SR, T)
 /* Write Special Register */
-#define XT_INS_WSR(SR, T) _XT_INS_FORMAT_RSR(0x130000, SR, T)
+#define XT_INS_WSR(X, SR, T) _XT_INS_FORMAT_RSR(X, 0x130000, SR, T)
 /* Swap Special Register */
-#define XT_INS_XSR(SR, T) _XT_INS_FORMAT_RSR(0x610000, SR, T)
+#define XT_INS_XSR(X, SR, T) _XT_INS_FORMAT_RSR(X, 0x610000, SR, T)
 
 /* Rotate Window by (-8..7) */
-#define XT_INS_ROTW(N) ((0x408000) | (((N) & 15) << 4))
+#define XT_INS_ROTW(X, N) (XT_ISBE(X) ? ((0x000804) | (((N) & 15) << 16)) << 8 : ((0x408000) | (((N) & 15) << 4)))
 
 /* Read User Register */
-#define XT_INS_RUR(UR, T) _XT_INS_FORMAT_RRR(0xE30000, UR, T)
+#define XT_INS_RUR(X, UR, T) _XT_INS_FORMAT_RRR(X, 0xE30000, UR, T)
 /* Write User Register */
-#define XT_INS_WUR(UR, T) _XT_INS_FORMAT_RSR(0xF30000, UR, T)
+#define XT_INS_WUR(X, UR, T) _XT_INS_FORMAT_RSR(X, 0xF30000, UR, T)
 
 /* Read Floating-Point Register */
-#define XT_INS_RFR(FR, T) _XT_INS_FORMAT_RRR(0xFA0000, (((FR) << 4) | 0x4), T)
+#define XT_INS_RFR(X, FR, T) _XT_INS_FORMAT_RRR(X, 0xFA0000, ((FR << 4) | 0x4), T)
 /* Write Floating-Point Register */
-#define XT_INS_WFR(FR, T) _XT_INS_FORMAT_RRR(0xFA0000, (((FR) << 4) | 0x5), T)
-
-/* 32-bit break */
-#define XT_INS_BREAK(IMM1, IMM2)  _XT_INS_FORMAT_RRR(0x000000, \
-               (((IMM1) & 0x0F) << 4) | ((IMM2) & 0x0F), 0x4)
-/* 16-bit break */
-#define XT_INS_BREAKN(IMM4)  _XT_INS_FORMAT_RRRN(0x00000D, IMM4, 0x2, 0xF)
+#define XT_INS_WFR(X, FR, T) _XT_INS_FORMAT_RRR(X, 0xFA0000, ((T << 4) | 0x5), FR)
 
-#define XT_INS_L32E(R, S, T) _XT_INS_FORMAT_RRI4(0x90000, 0, R, S, T)
-#define XT_INS_S32E(R, S, T) _XT_INS_FORMAT_RRI4(0x490000, 0, R, S, T)
-#define XT_INS_L32E_S32E_MASK   0xFF000F
+#define XT_INS_L32E(X, R, S, T) _XT_INS_FORMAT_RRI4(X, 0x090000, 0, R, S, T)
+#define XT_INS_S32E(X, R, S, T) _XT_INS_FORMAT_RRI4(X, 0x490000, 0, R, S, T)
+#define XT_INS_L32E_S32E_MASK(X)   (XT_ISBE(X) ? 0xF000FF << 8 : 0xFF000F)
 
-#define XT_INS_RFWO 0x3400
-#define XT_INS_RFWU 0x3500
-#define XT_INS_RFWO_RFWU_MASK   0xFFFFFF
+#define XT_INS_RFWO(X) (XT_ISBE(X) ? 0x004300 << 8 : 0x003400)
+#define XT_INS_RFWU(X) (XT_ISBE(X) ? 0x005300 << 8 : 0x003500)
+#define XT_INS_RFWO_RFWU_MASK(X)   (XT_ISBE(X) ? 0xFFFFFF << 8 : 0xFFFFFF)
 
 #define XT_WATCHPOINTS_NUM_MAX  2
 
-/* Special register number macro for DDR register.
-* this gets used a lot so making a shortcut to it is
-* useful.
-*/
-#define XT_SR_DDR         (xtensa_regs[XT_REG_IDX_OCD_DDR].reg_num)
-
-/*Same thing for A3/A4 */
+/* Special register number macro for DDR, PS, WB, A3, A4 registers.
+ * These get used a lot so making a shortcut is useful.
+ */
+#define XT_SR_DDR         (xtensa_regs[XT_REG_IDX_DDR].reg_num)
+#define XT_SR_PS          (xtensa_regs[XT_REG_IDX_PS].reg_num)
+#define XT_SR_WB          (xtensa_regs[XT_REG_IDX_WINDOWBASE].reg_num)
 #define XT_REG_A3         (xtensa_regs[XT_REG_IDX_AR3].reg_num)
 #define XT_REG_A4         (xtensa_regs[XT_REG_IDX_AR4].reg_num)
 
-#define XT_PC_REG_NUM_BASE          (176)
-#define XT_SW_BREAKPOINTS_MAX_NUM   32
-
-const struct xtensa_reg_desc xtensa_regs[XT_NUM_REGS] = {
-       { "pc", XT_PC_REG_NUM_BASE /*+XT_DEBUGLEVEL*/, XT_REG_SPECIAL, 0 },             /* actually epc[debuglevel] */
-       { "ar0", 0x00, XT_REG_GENERAL, 0 },
-       { "ar1", 0x01, XT_REG_GENERAL, 0 },
-       { "ar2", 0x02, XT_REG_GENERAL, 0 },
-       { "ar3", 0x03, XT_REG_GENERAL, 0 },
-       { "ar4", 0x04, XT_REG_GENERAL, 0 },
-       { "ar5", 0x05, XT_REG_GENERAL, 0 },
-       { "ar6", 0x06, XT_REG_GENERAL, 0 },
-       { "ar7", 0x07, XT_REG_GENERAL, 0 },
-       { "ar8", 0x08, XT_REG_GENERAL, 0 },
-       { "ar9", 0x09, XT_REG_GENERAL, 0 },
-       { "ar10", 0x0A, XT_REG_GENERAL, 0 },
-       { "ar11", 0x0B, XT_REG_GENERAL, 0 },
-       { "ar12", 0x0C, XT_REG_GENERAL, 0 },
-       { "ar13", 0x0D, XT_REG_GENERAL, 0 },
-       { "ar14", 0x0E, XT_REG_GENERAL, 0 },
-       { "ar15", 0x0F, XT_REG_GENERAL, 0 },
-       { "ar16", 0x10, XT_REG_GENERAL, 0 },
-       { "ar17", 0x11, XT_REG_GENERAL, 0 },
-       { "ar18", 0x12, XT_REG_GENERAL, 0 },
-       { "ar19", 0x13, XT_REG_GENERAL, 0 },
-       { "ar20", 0x14, XT_REG_GENERAL, 0 },
-       { "ar21", 0x15, XT_REG_GENERAL, 0 },
-       { "ar22", 0x16, XT_REG_GENERAL, 0 },
-       { "ar23", 0x17, XT_REG_GENERAL, 0 },
-       { "ar24", 0x18, XT_REG_GENERAL, 0 },
-       { "ar25", 0x19, XT_REG_GENERAL, 0 },
-       { "ar26", 0x1A, XT_REG_GENERAL, 0 },
-       { "ar27", 0x1B, XT_REG_GENERAL, 0 },
-       { "ar28", 0x1C, XT_REG_GENERAL, 0 },
-       { "ar29", 0x1D, XT_REG_GENERAL, 0 },
-       { "ar30", 0x1E, XT_REG_GENERAL, 0 },
-       { "ar31", 0x1F, XT_REG_GENERAL, 0 },
-       { "ar32", 0x20, XT_REG_GENERAL, 0 },
-       { "ar33", 0x21, XT_REG_GENERAL, 0 },
-       { "ar34", 0x22, XT_REG_GENERAL, 0 },
-       { "ar35", 0x23, XT_REG_GENERAL, 0 },
-       { "ar36", 0x24, XT_REG_GENERAL, 0 },
-       { "ar37", 0x25, XT_REG_GENERAL, 0 },
-       { "ar38", 0x26, XT_REG_GENERAL, 0 },
-       { "ar39", 0x27, XT_REG_GENERAL, 0 },
-       { "ar40", 0x28, XT_REG_GENERAL, 0 },
-       { "ar41", 0x29, XT_REG_GENERAL, 0 },
-       { "ar42", 0x2A, XT_REG_GENERAL, 0 },
-       { "ar43", 0x2B, XT_REG_GENERAL, 0 },
-       { "ar44", 0x2C, XT_REG_GENERAL, 0 },
-       { "ar45", 0x2D, XT_REG_GENERAL, 0 },
-       { "ar46", 0x2E, XT_REG_GENERAL, 0 },
-       { "ar47", 0x2F, XT_REG_GENERAL, 0 },
-       { "ar48", 0x30, XT_REG_GENERAL, 0 },
-       { "ar49", 0x31, XT_REG_GENERAL, 0 },
-       { "ar50", 0x32, XT_REG_GENERAL, 0 },
-       { "ar51", 0x33, XT_REG_GENERAL, 0 },
-       { "ar52", 0x34, XT_REG_GENERAL, 0 },
-       { "ar53", 0x35, XT_REG_GENERAL, 0 },
-       { "ar54", 0x36, XT_REG_GENERAL, 0 },
-       { "ar55", 0x37, XT_REG_GENERAL, 0 },
-       { "ar56", 0x38, XT_REG_GENERAL, 0 },
-       { "ar57", 0x39, XT_REG_GENERAL, 0 },
-       { "ar58", 0x3A, XT_REG_GENERAL, 0 },
-       { "ar59", 0x3B, XT_REG_GENERAL, 0 },
-       { "ar60", 0x3C, XT_REG_GENERAL, 0 },
-       { "ar61", 0x3D, XT_REG_GENERAL, 0 },
-       { "ar62", 0x3E, XT_REG_GENERAL, 0 },
-       { "ar63", 0x3F, XT_REG_GENERAL, 0 },
-       { "lbeg", 0x00, XT_REG_SPECIAL, 0 },
-       { "lend", 0x01, XT_REG_SPECIAL, 0 },
-       { "lcount", 0x02, XT_REG_SPECIAL, 0 },
-       { "sar", 0x03, XT_REG_SPECIAL, 0 },
-       { "windowbase", 0x48, XT_REG_SPECIAL, 0 },
-       { "windowstart", 0x49, XT_REG_SPECIAL, 0 },
-       { "configid0", 0xB0, XT_REG_SPECIAL, 0 },
-       { "configid1", 0xD0, XT_REG_SPECIAL, 0 },
-       { "ps", 0xC6, XT_REG_SPECIAL, 0 },                      /* actually EPS[debuglevel] */
-       { "threadptr", 0xE7, XT_REG_USER, 0 },
-       { "br", 0x04, XT_REG_SPECIAL, 0 },
-       { "scompare1", 0x0C, XT_REG_SPECIAL, 0 },
-       { "acclo", 0x10, XT_REG_SPECIAL, 0 },
-       { "acchi", 0x11, XT_REG_SPECIAL, 0 },
-       { "m0", 0x20, XT_REG_SPECIAL, 0 },
-       { "m1", 0x21, XT_REG_SPECIAL, 0 },
-       { "m2", 0x22, XT_REG_SPECIAL, 0 },
-       { "m3", 0x23, XT_REG_SPECIAL, 0 },
-       { "f0", 0x00, XT_REG_FR, XT_REGF_COPROC0 },
-       { "f1", 0x01, XT_REG_FR, XT_REGF_COPROC0 },
-       { "f2", 0x02, XT_REG_FR, XT_REGF_COPROC0 },
-       { "f3", 0x03, XT_REG_FR, XT_REGF_COPROC0 },
-       { "f4", 0x04, XT_REG_FR, XT_REGF_COPROC0 },
-       { "f5", 0x05, XT_REG_FR, XT_REGF_COPROC0 },
-       { "f6", 0x06, XT_REG_FR, XT_REGF_COPROC0 },
-       { "f7", 0x07, XT_REG_FR, XT_REGF_COPROC0 },
-       { "f8", 0x08, XT_REG_FR, XT_REGF_COPROC0 },
-       { "f9", 0x09, XT_REG_FR, XT_REGF_COPROC0 },
-       { "f10", 0x0A, XT_REG_FR, XT_REGF_COPROC0 },
-       { "f11", 0x0B, XT_REG_FR, XT_REGF_COPROC0 },
-       { "f12", 0x0C, XT_REG_FR, XT_REGF_COPROC0 },
-       { "f13", 0x0D, XT_REG_FR, XT_REGF_COPROC0 },
-       { "f14", 0x0E, XT_REG_FR, XT_REGF_COPROC0 },
-       { "f15", 0x0F, XT_REG_FR, XT_REGF_COPROC0 },
-       { "fcr", 0xE8, XT_REG_USER, XT_REGF_COPROC0 },
-       { "fsr", 0xE9, XT_REG_USER, XT_REGF_COPROC0 },
-       { "mmid", 0x59, XT_REG_SPECIAL, XT_REGF_NOREAD },
-       { "ibreakenable", 0x60, XT_REG_SPECIAL, 0 },
-       { "memctl", 0x61, XT_REG_SPECIAL, 0 },
-       { "atomctl", 0x63, XT_REG_SPECIAL, 0 },
-       { "ibreaka0", 0x80, XT_REG_SPECIAL, 0 },
-       { "ibreaka1", 0x81, XT_REG_SPECIAL, 0 },
-       { "dbreaka0", 0x90, XT_REG_SPECIAL, 0 },
-       { "dbreaka1", 0x91, XT_REG_SPECIAL, 0 },
-       { "dbreakc0", 0xA0, XT_REG_SPECIAL, 0 },
-       { "dbreakc1", 0xA1, XT_REG_SPECIAL, 0 },
-       { "epc1", 0xB1, XT_REG_SPECIAL, 0 },
-       { "epc2", 0xB2, XT_REG_SPECIAL, 0 },
-       { "epc3", 0xB3, XT_REG_SPECIAL, 0 },
-       { "epc4", 0xB4, XT_REG_SPECIAL, 0 },
-       { "epc5", 0xB5, XT_REG_SPECIAL, 0 },
-       { "epc6", 0xB6, XT_REG_SPECIAL, 0 },
-       { "epc7", 0xB7, XT_REG_SPECIAL, 0 },
-       { "depc", 0xC0, XT_REG_SPECIAL, 0 },
-       { "eps2", 0xC2, XT_REG_SPECIAL, 0 },
-       { "eps3", 0xC3, XT_REG_SPECIAL, 0 },
-       { "eps4", 0xC4, XT_REG_SPECIAL, 0 },
-       { "eps5", 0xC5, XT_REG_SPECIAL, 0 },
-       { "eps6", 0xC6, XT_REG_SPECIAL, 0 },
-       { "eps7", 0xC7, XT_REG_SPECIAL, 0 },
-       { "excsave1", 0xD1, XT_REG_SPECIAL, 0 },
-       { "excsave2", 0xD2, XT_REG_SPECIAL, 0 },
-       { "excsave3", 0xD3, XT_REG_SPECIAL, 0 },
-       { "excsave4", 0xD4, XT_REG_SPECIAL, 0 },
-       { "excsave5", 0xD5, XT_REG_SPECIAL, 0 },
-       { "excsave6", 0xD6, XT_REG_SPECIAL, 0 },
-       { "excsave7", 0xD7, XT_REG_SPECIAL, 0 },
-       { "cpenable", 0xE0, XT_REG_SPECIAL, 0 },
-       { "interrupt", 0xE2, XT_REG_SPECIAL, 0 },
-       { "intset", 0xE2, XT_REG_SPECIAL, XT_REGF_NOREAD },
-       { "intclear", 0xE3, XT_REG_SPECIAL, XT_REGF_NOREAD },
-       { "intenable", 0xE4, XT_REG_SPECIAL, 0 },
-       { "vecbase", 0xE7, XT_REG_SPECIAL, 0 },
-       { "exccause", 0xE8, XT_REG_SPECIAL, 0 },
-       { "debugcause", 0xE9, XT_REG_SPECIAL, 0 },
-       { "ccount", 0xEA, XT_REG_SPECIAL, 0 },
-       { "prid", 0xEB, XT_REG_SPECIAL, 0 },
-       { "icount", 0xEC, XT_REG_SPECIAL, 0 },
-       { "icountlevel", 0xED, XT_REG_SPECIAL, 0 },
-       { "excvaddr", 0xEE, XT_REG_SPECIAL, 0 },
-       { "ccompare0", 0xF0, XT_REG_SPECIAL, 0 },
-       { "ccompare1", 0xF1, XT_REG_SPECIAL, 0 },
-       { "ccompare2", 0xF2, XT_REG_SPECIAL, 0 },
-       { "misc0", 0xF4, XT_REG_SPECIAL, 0 },
-       { "misc1", 0xF5, XT_REG_SPECIAL, 0 },
-       { "misc2", 0xF6, XT_REG_SPECIAL, 0 },
-       { "misc3", 0xF7, XT_REG_SPECIAL, 0 },
-       { "litbase", 0x05, XT_REG_SPECIAL, 0 },
-       { "ptevaddr", 0x53, XT_REG_SPECIAL, 0 },
-       { "rasid", 0x5A, XT_REG_SPECIAL, 0 },
-       { "itlbcfg", 0x5B, XT_REG_SPECIAL, 0 },
-       { "dtlbcfg", 0x5C, XT_REG_SPECIAL, 0 },
-       { "mepc", 0x6A, XT_REG_SPECIAL, 0 },
-       { "meps", 0x6B, XT_REG_SPECIAL, 0 },
-       { "mesave", 0x6C, XT_REG_SPECIAL, 0 },
-       { "mesr", 0x6D, XT_REG_SPECIAL, 0 },
-       { "mecr", 0x6E, XT_REG_SPECIAL, 0 },
-       { "mevaddr", 0x6F, XT_REG_SPECIAL, 0 },
-       { "a0", XT_REG_IDX_AR0, XT_REG_RELGEN, 0 },     /* WARNING: For these registers, regnum points to the */
-       { "a1", XT_REG_IDX_AR1, XT_REG_RELGEN, 0 },     /* index of the corresponding ARxregisters, NOT to */
-       { "a2", XT_REG_IDX_AR2, XT_REG_RELGEN, 0 },     /* the processor register number! */
-       { "a3", XT_REG_IDX_AR3, XT_REG_RELGEN, 0 },
-       { "a4", XT_REG_IDX_AR4, XT_REG_RELGEN, 0 },
-       { "a5", XT_REG_IDX_AR5, XT_REG_RELGEN, 0 },
-       { "a6", XT_REG_IDX_AR6, XT_REG_RELGEN, 0 },
-       { "a7", XT_REG_IDX_AR7, XT_REG_RELGEN, 0 },
-       { "a8", XT_REG_IDX_AR8, XT_REG_RELGEN, 0 },
-       { "a9", XT_REG_IDX_AR9, XT_REG_RELGEN, 0 },
-       { "a10", XT_REG_IDX_AR10, XT_REG_RELGEN, 0 },
-       { "a11", XT_REG_IDX_AR11, XT_REG_RELGEN, 0 },
-       { "a12", XT_REG_IDX_AR12, XT_REG_RELGEN, 0 },
-       { "a13", XT_REG_IDX_AR13, XT_REG_RELGEN, 0 },
-       { "a14", XT_REG_IDX_AR14, XT_REG_RELGEN, 0 },
-       { "a15", XT_REG_IDX_AR15, XT_REG_RELGEN, 0 },
-
-       { "pwrctl", 0x68, XT_REG_DEBUG, XT_REGF_NOREAD },
-       { "pwrstat", 0x68, XT_REG_DEBUG, XT_REGF_NOREAD },
-       { "eristat", 0x68, XT_REG_DEBUG, XT_REGF_NOREAD },
-       { "cs_itctrl", 0x68, XT_REG_DEBUG, XT_REGF_NOREAD },
-       { "cs_claimset", 0x68, XT_REG_DEBUG, XT_REGF_NOREAD },
-       { "cs_claimclr", 0x68, XT_REG_DEBUG, XT_REGF_NOREAD },
-       { "cs_lockaccess", 0x68, XT_REG_DEBUG, XT_REGF_NOREAD },
-       { "cs_lockstatus", 0x68, XT_REG_DEBUG, XT_REGF_NOREAD },
-       { "cs_authstatus", 0x68, XT_REG_DEBUG, XT_REGF_NOREAD },
-       { "fault_info", 0x68, XT_REG_DEBUG, XT_REGF_NOREAD },
-       { "trax_id", 0x68, XT_REG_DEBUG, XT_REGF_NOREAD },
-       { "trax_ctrl", 0x68, XT_REG_DEBUG, XT_REGF_NOREAD },
-       { "trax_stat", 0x68, XT_REG_DEBUG, XT_REGF_NOREAD },
-       { "trax_data", 0x68, XT_REG_DEBUG, XT_REGF_NOREAD },
-       { "trax_addr", 0x68, XT_REG_DEBUG, XT_REGF_NOREAD },
-       { "trax_pctrigger", 0x68, XT_REG_DEBUG, XT_REGF_NOREAD },
-       { "trax_pcmatch", 0x68, XT_REG_DEBUG, XT_REGF_NOREAD },
-       { "trax_delay", 0x68, XT_REG_DEBUG, XT_REGF_NOREAD },
-       { "trax_memstart", 0x68, XT_REG_DEBUG, XT_REGF_NOREAD },
-       { "trax_memend", 0x68, XT_REG_DEBUG, XT_REGF_NOREAD },
-       { "pmg", 0x68, XT_REG_DEBUG, XT_REGF_NOREAD },
-       { "pmoc", 0x68, XT_REG_DEBUG, XT_REGF_NOREAD },
-       { "pm0", 0x68, XT_REG_DEBUG, XT_REGF_NOREAD },
-       { "pm1", 0x68, XT_REG_DEBUG, XT_REGF_NOREAD },
-       { "pmctrl0", 0x68, XT_REG_DEBUG, XT_REGF_NOREAD },
-       { "pmctrl1", 0x68, XT_REG_DEBUG, XT_REGF_NOREAD },
-       { "pmstat0", 0x68, XT_REG_DEBUG, XT_REGF_NOREAD },
-       { "pmstat1", 0x68, XT_REG_DEBUG, XT_REGF_NOREAD },
-       { "ocd_id", 0x68, XT_REG_DEBUG, XT_REGF_NOREAD },
-       { "ocd_dcrclr", 0x68, XT_REG_DEBUG, XT_REGF_NOREAD },
-       { "ocd_dcrset", 0x68, XT_REG_DEBUG, XT_REGF_NOREAD },
-       { "ocd_dsr", 0x68, XT_REG_DEBUG, XT_REGF_NOREAD },
-       { "ddr", 0x68, XT_REG_DEBUG, XT_REGF_NOREAD },
+#define XT_PS_REG_NUM_BASE          (0xc0U)    /* (EPS2 - 2), for adding DBGLEVEL */
+#define XT_PC_REG_NUM_BASE          (0xb0U)    /* (EPC1 - 1), for adding DBGLEVEL */
+#define XT_PC_REG_NUM_VIRTUAL       (0xffU)    /* Marker for computing PC (EPC[DBGLEVEL) */
+#define XT_PC_DBREG_NUM_BASE        (0x20U)    /* External (i.e., GDB) access */
+
+#define XT_SW_BREAKPOINTS_MAX_NUM       32
+#define XT_HW_IBREAK_MAX_NUM            2
+#define XT_HW_DBREAK_MAX_NUM            2
+
+struct xtensa_reg_desc xtensa_regs[XT_NUM_REGS] = {
+       XT_MK_REG_DESC("pc", XT_PC_REG_NUM_VIRTUAL, XT_REG_SPECIAL, 0),
+       XT_MK_REG_DESC("ar0", 0x00, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar1", 0x01, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar2", 0x02, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar3", 0x03, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar4", 0x04, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar5", 0x05, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar6", 0x06, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar7", 0x07, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar8", 0x08, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar9", 0x09, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar10", 0x0A, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar11", 0x0B, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar12", 0x0C, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar13", 0x0D, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar14", 0x0E, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar15", 0x0F, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar16", 0x10, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar17", 0x11, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar18", 0x12, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar19", 0x13, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar20", 0x14, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar21", 0x15, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar22", 0x16, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar23", 0x17, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar24", 0x18, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar25", 0x19, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar26", 0x1A, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar27", 0x1B, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar28", 0x1C, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar29", 0x1D, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar30", 0x1E, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar31", 0x1F, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar32", 0x20, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar33", 0x21, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar34", 0x22, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar35", 0x23, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar36", 0x24, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar37", 0x25, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar38", 0x26, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar39", 0x27, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar40", 0x28, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar41", 0x29, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar42", 0x2A, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar43", 0x2B, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar44", 0x2C, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar45", 0x2D, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar46", 0x2E, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar47", 0x2F, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar48", 0x30, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar49", 0x31, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar50", 0x32, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar51", 0x33, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar52", 0x34, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar53", 0x35, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar54", 0x36, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar55", 0x37, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar56", 0x38, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar57", 0x39, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar58", 0x3A, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar59", 0x3B, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar60", 0x3C, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar61", 0x3D, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar62", 0x3E, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("ar63", 0x3F, XT_REG_GENERAL, 0),
+       XT_MK_REG_DESC("windowbase", 0x48, XT_REG_SPECIAL, 0),
+       XT_MK_REG_DESC("windowstart", 0x49, XT_REG_SPECIAL, 0),
+       XT_MK_REG_DESC("ps", 0xE6, XT_REG_SPECIAL, 0),  /* PS (not mapped through EPS[]) */
+       XT_MK_REG_DESC("ibreakenable", 0x60, XT_REG_SPECIAL, 0),
+       XT_MK_REG_DESC("ddr", 0x68, XT_REG_DEBUG, XT_REGF_NOREAD),
+       XT_MK_REG_DESC("ibreaka0", 0x80, XT_REG_SPECIAL, 0),
+       XT_MK_REG_DESC("ibreaka1", 0x81, XT_REG_SPECIAL, 0),
+       XT_MK_REG_DESC("dbreaka0", 0x90, XT_REG_SPECIAL, 0),
+       XT_MK_REG_DESC("dbreaka1", 0x91, XT_REG_SPECIAL, 0),
+       XT_MK_REG_DESC("dbreakc0", 0xA0, XT_REG_SPECIAL, 0),
+       XT_MK_REG_DESC("dbreakc1", 0xA1, XT_REG_SPECIAL, 0),
+       XT_MK_REG_DESC("cpenable", 0xE0, XT_REG_SPECIAL, 0),
+       XT_MK_REG_DESC("exccause", 0xE8, XT_REG_SPECIAL, 0),
+       XT_MK_REG_DESC("debugcause", 0xE9, XT_REG_SPECIAL, 0),
+       XT_MK_REG_DESC("icount", 0xEC, XT_REG_SPECIAL, 0),
+       XT_MK_REG_DESC("icountlevel", 0xED, XT_REG_SPECIAL, 0),
+
+       /* WARNING: For these registers, regnum points to the
+        * index of the corresponding ARx registers, NOT to
+        * the processor register number! */
+       XT_MK_REG_DESC("a0", XT_REG_IDX_AR0, XT_REG_RELGEN, 0),
+       XT_MK_REG_DESC("a1", XT_REG_IDX_AR1, XT_REG_RELGEN, 0),
+       XT_MK_REG_DESC("a2", XT_REG_IDX_AR2, XT_REG_RELGEN, 0),
+       XT_MK_REG_DESC("a3", XT_REG_IDX_AR3, XT_REG_RELGEN, 0),
+       XT_MK_REG_DESC("a4", XT_REG_IDX_AR4, XT_REG_RELGEN, 0),
+       XT_MK_REG_DESC("a5", XT_REG_IDX_AR5, XT_REG_RELGEN, 0),
+       XT_MK_REG_DESC("a6", XT_REG_IDX_AR6, XT_REG_RELGEN, 0),
+       XT_MK_REG_DESC("a7", XT_REG_IDX_AR7, XT_REG_RELGEN, 0),
+       XT_MK_REG_DESC("a8", XT_REG_IDX_AR8, XT_REG_RELGEN, 0),
+       XT_MK_REG_DESC("a9", XT_REG_IDX_AR9, XT_REG_RELGEN, 0),
+       XT_MK_REG_DESC("a10", XT_REG_IDX_AR10, XT_REG_RELGEN, 0),
+       XT_MK_REG_DESC("a11", XT_REG_IDX_AR11, XT_REG_RELGEN, 0),
+       XT_MK_REG_DESC("a12", XT_REG_IDX_AR12, XT_REG_RELGEN, 0),
+       XT_MK_REG_DESC("a13", XT_REG_IDX_AR13, XT_REG_RELGEN, 0),
+       XT_MK_REG_DESC("a14", XT_REG_IDX_AR14, XT_REG_RELGEN, 0),
+       XT_MK_REG_DESC("a15", XT_REG_IDX_AR15, XT_REG_RELGEN, 0),
 };
 
-
 /**
  * Types of memory used at xtensa target
  */
@@ -343,11 +289,27 @@ enum xtensa_mem_region_type {
        XTENSA_MEM_REG_IRAM,
        XTENSA_MEM_REG_DROM,
        XTENSA_MEM_REG_DRAM,
-       XTENSA_MEM_REG_URAM,
-       XTENSA_MEM_REG_XLMI,
+       XTENSA_MEM_REG_SRAM,
+       XTENSA_MEM_REG_SROM,
        XTENSA_MEM_REGS_NUM
 };
 
+/* Register definition as union for list allocation */
+union xtensa_reg_val_u {
+       xtensa_reg_val_t val;
+       uint8_t buf[4];
+};
+
+const struct xtensa_keyval_info_s xt_qerr[XT_QERR_NUM] = {
+       { .chrval = "E00", .intval = ERROR_FAIL },
+       { .chrval = "E01", .intval = ERROR_FAIL },
+       { .chrval = "E02", .intval = ERROR_COMMAND_ARGUMENT_INVALID },
+       { .chrval = "E03", .intval = ERROR_FAIL },
+};
+
+/* Set to true for extra debug logging */
+static const bool xtensa_extra_debug_log;
+
 /**
  * Gets a config for the specific mem type
  */
@@ -364,10 +326,10 @@ static inline const struct xtensa_local_mem_config *xtensa_get_mem_config(
                return &xtensa->core_config->drom;
        case XTENSA_MEM_REG_DRAM:
                return &xtensa->core_config->dram;
-       case XTENSA_MEM_REG_URAM:
-               return &xtensa->core_config->uram;
-       case XTENSA_MEM_REG_XLMI:
-               return &xtensa->core_config->xlmi;
+       case XTENSA_MEM_REG_SRAM:
+               return &xtensa->core_config->sram;
+       case XTENSA_MEM_REG_SROM:
+               return &xtensa->core_config->srom;
        default:
                return NULL;
        }
@@ -410,14 +372,47 @@ static inline const struct xtensa_local_mem_region_config *xtensa_target_memory_
        return NULL;
 }
 
+static inline bool xtensa_is_cacheable(const struct xtensa_cache_config *cache,
+       const struct xtensa_local_mem_config *mem,
+       target_addr_t address)
+{
+       if (!cache->size)
+               return false;
+       return xtensa_memory_region_find(mem, address);
+}
+
+static inline bool xtensa_is_icacheable(struct xtensa *xtensa, target_addr_t address)
+{
+       return xtensa_is_cacheable(&xtensa->core_config->icache, &xtensa->core_config->iram, address) ||
+              xtensa_is_cacheable(&xtensa->core_config->icache, &xtensa->core_config->irom, address) ||
+              xtensa_is_cacheable(&xtensa->core_config->icache, &xtensa->core_config->sram, address) ||
+              xtensa_is_cacheable(&xtensa->core_config->icache, &xtensa->core_config->srom, address);
+}
+
+static inline bool xtensa_is_dcacheable(struct xtensa *xtensa, target_addr_t address)
+{
+       return xtensa_is_cacheable(&xtensa->core_config->dcache, &xtensa->core_config->dram, address) ||
+              xtensa_is_cacheable(&xtensa->core_config->dcache, &xtensa->core_config->drom, address) ||
+              xtensa_is_cacheable(&xtensa->core_config->dcache, &xtensa->core_config->sram, address) ||
+              xtensa_is_cacheable(&xtensa->core_config->dcache, &xtensa->core_config->srom, address);
+}
+
 static int xtensa_core_reg_get(struct reg *reg)
 {
-       /*We don't need this because we read all registers on halt anyway. */
+       /* We don't need this because we read all registers on halt anyway. */
        struct xtensa *xtensa = (struct xtensa *)reg->arch_info;
        struct target *target = xtensa->target;
 
        if (target->state != TARGET_HALTED)
                return ERROR_TARGET_NOT_HALTED;
+       if (!reg->exist) {
+               if (strncmp(reg->name, "?0x", 3) == 0) {
+                       unsigned int regnum = strtoul(reg->name + 1, 0, 0);
+                       LOG_WARNING("Read unknown register 0x%04x ignored", regnum);
+                       return ERROR_OK;
+               }
+               return ERROR_COMMAND_ARGUMENT_INVALID;
+       }
        return ERROR_OK;
 }
 
@@ -430,7 +425,31 @@ static int xtensa_core_reg_set(struct reg *reg, uint8_t *buf)
        if (target->state != TARGET_HALTED)
                return ERROR_TARGET_NOT_HALTED;
 
+       if (!reg->exist) {
+               if (strncmp(reg->name, "?0x", 3) == 0) {
+                       unsigned int regnum = strtoul(reg->name + 1, 0, 0);
+                       LOG_WARNING("Write unknown register 0x%04x ignored", regnum);
+                       return ERROR_OK;
+               }
+               return ERROR_COMMAND_ARGUMENT_INVALID;
+       }
+
        buf_cpy(buf, reg->value, reg->size);
+
+       if (xtensa->core_config->windowed) {
+               /* If the user updates a potential scratch register, track for conflicts */
+               for (enum xtensa_ar_scratch_set_e s = 0; s < XT_AR_SCRATCH_NUM; s++) {
+                       if (strcmp(reg->name, xtensa->scratch_ars[s].chrval) == 0) {
+                               LOG_DEBUG("Scratch reg %s [0x%08" PRIx32 "] set from gdb", reg->name,
+                                       buf_get_u32(reg->value, 0, 32));
+                               LOG_DEBUG("scratch_ars mapping: a3/%s, a4/%s",
+                                       xtensa->scratch_ars[XT_AR_SCRATCH_AR3].chrval,
+                                       xtensa->scratch_ars[XT_AR_SCRATCH_AR4].chrval);
+                               xtensa->scratch_ars[s].intval = true;
+                               break;
+                       }
+               }
+       }
        reg->dirty = true;
        reg->valid = true;
 
@@ -442,26 +461,13 @@ static const struct reg_arch_type xtensa_reg_type = {
        .set = xtensa_core_reg_set,
 };
 
-const struct reg_arch_type xtensa_user_reg_u32_type = {
-       .get = xtensa_core_reg_get,
-       .set = xtensa_core_reg_set,
-};
-
-const struct reg_arch_type xtensa_user_reg_u128_type = {
-       .get = xtensa_core_reg_get,
-       .set = xtensa_core_reg_set,
-};
-
-static inline size_t xtensa_insn_size_get(uint32_t insn)
-{
-       return insn & BIT(3) ? 2 : XT_ISNS_SZ_MAX;
-}
-
 /* Convert a register index that's indexed relative to windowbase, to the real address. */
-static enum xtensa_reg_id xtensa_windowbase_offset_to_canonical(enum xtensa_reg_id reg_idx, int windowbase)
+static enum xtensa_reg_id xtensa_windowbase_offset_to_canonical(struct xtensa *xtensa,
+       enum xtensa_reg_id reg_idx,
+       int windowbase)
 {
        unsigned int idx;
-       if (reg_idx >= XT_REG_IDX_AR0 && reg_idx <= XT_REG_IDX_AR63) {
+       if (reg_idx >= XT_REG_IDX_AR0 && reg_idx <= XT_REG_IDX_ARLAST) {
                idx = reg_idx - XT_REG_IDX_AR0;
        } else if (reg_idx >= XT_REG_IDX_A0 && reg_idx <= XT_REG_IDX_A15) {
                idx = reg_idx - XT_REG_IDX_A0;
@@ -469,12 +475,14 @@ static enum xtensa_reg_id xtensa_windowbase_offset_to_canonical(enum xtensa_reg_
                LOG_ERROR("Error: can't convert register %d to non-windowbased register!", reg_idx);
                return -1;
        }
-       return ((idx + windowbase * 4) & 63) + XT_REG_IDX_AR0;
+       return ((idx + windowbase * 4) & (xtensa->core_config->aregs_num - 1)) + XT_REG_IDX_AR0;
 }
 
-static enum xtensa_reg_id xtensa_canonical_to_windowbase_offset(enum xtensa_reg_id reg_idx, int windowbase)
+static enum xtensa_reg_id xtensa_canonical_to_windowbase_offset(struct xtensa *xtensa,
+       enum xtensa_reg_id reg_idx,
+       int windowbase)
 {
-       return xtensa_windowbase_offset_to_canonical(reg_idx, -windowbase);
+       return xtensa_windowbase_offset_to_canonical(xtensa, reg_idx, -windowbase);
 }
 
 static void xtensa_mark_register_dirty(struct xtensa *xtensa, enum xtensa_reg_id reg_idx)
@@ -483,42 +491,25 @@ static void xtensa_mark_register_dirty(struct xtensa *xtensa, enum xtensa_reg_id
        reg_list[reg_idx].dirty = true;
 }
 
-static int xtensa_queue_dbg_reg_read(struct xtensa *xtensa, unsigned int reg, uint8_t *data)
-{
-       struct xtensa_debug_module *dm = &xtensa->dbg_mod;
-
-       if (!xtensa->core_config->trace.enabled &&
-               (reg <= NARADR_MEMADDREND || (reg >= NARADR_PMG && reg <= NARADR_PMSTAT7))) {
-               LOG_ERROR("Can not access %u reg when Trace Port option disabled!", reg);
-               return ERROR_FAIL;
-       }
-       return dm->dbg_ops->queue_reg_read(dm, reg, data);
-}
-
-static int xtensa_queue_dbg_reg_write(struct xtensa *xtensa, unsigned int reg, uint32_t data)
-{
-       struct xtensa_debug_module *dm = &xtensa->dbg_mod;
-
-       if (!xtensa->core_config->trace.enabled &&
-               (reg <= NARADR_MEMADDREND || (reg >= NARADR_PMG && reg <= NARADR_PMSTAT7))) {
-               LOG_ERROR("Can not access %u reg when Trace Port option disabled!", reg);
-               return ERROR_FAIL;
-       }
-       return dm->dbg_ops->queue_reg_write(dm, reg, data);
-}
-
 static void xtensa_queue_exec_ins(struct xtensa *xtensa, uint32_t ins)
 {
        xtensa_queue_dbg_reg_write(xtensa, NARADR_DIR0EXEC, ins);
 }
 
-static bool xtensa_reg_is_readable(enum xtensa_reg_flags flags, xtensa_reg_val_t cpenable)
+static void xtensa_queue_exec_ins_wide(struct xtensa *xtensa, uint8_t *ops, uint8_t oplen)
 {
-       if (flags & XT_REGF_NOREAD)
-               return false;
-       if ((flags & XT_REGF_COPROC0) && (cpenable & BIT(0)) == 0)
-               return false;
-       return true;
+       if ((oplen > 0) && (oplen <= 64)) {
+               uint32_t opsw[8] = { 0, 0, 0, 0, 0, 0, 0, 0 };  /* 8 DIRx regs: max width 64B */
+               uint8_t oplenw = (oplen + 3) / 4;
+               if (xtensa->target->endianness == TARGET_BIG_ENDIAN)
+                       buf_bswap32((uint8_t *)opsw, ops, oplenw * 4);
+               else
+                       memcpy(opsw, ops, oplen);
+               for (int32_t i = oplenw - 1; i > 0; i--)
+                       xtensa_queue_dbg_reg_write(xtensa, NARADR_DIR0 + i, opsw[i]);
+               /* Write DIR0EXEC last */
+               xtensa_queue_dbg_reg_write(xtensa, NARADR_DIR0EXEC, opsw[0]);
+       }
 }
 
 static int xtensa_queue_pwr_reg_write(struct xtensa *xtensa, unsigned int reg, uint32_t data)
@@ -527,63 +518,67 @@ static int xtensa_queue_pwr_reg_write(struct xtensa *xtensa, unsigned int reg, u
        return dm->pwr_ops->queue_reg_write(dm, reg, data);
 }
 
-static bool xtensa_special_reg_exists(struct xtensa *xtensa, enum xtensa_reg_id reg_idx)
-{
-       /* TODO: array of size XT_NUM_REGS can be used here to map special register ID to
-        * corresponding config option 'enabled' flag */
-       if (reg_idx >= XT_REG_IDX_LBEG && reg_idx <= XT_REG_IDX_LCOUNT)
-               return xtensa->core_config->loop;
-       else if (reg_idx == XT_REG_IDX_BR)
-               return xtensa->core_config->boolean;
-       else if (reg_idx == XT_REG_IDX_LITBASE)
-               return xtensa->core_config->ext_l32r;
-       else if (reg_idx == XT_REG_IDX_SCOMPARE1 || reg_idx == XT_REG_IDX_ATOMCTL)
-               return xtensa->core_config->cond_store;
-       else if (reg_idx >= XT_REG_IDX_ACCLO && reg_idx <= XT_REG_IDX_M3)
-               return xtensa->core_config->mac16;
-       else if (reg_idx == XT_REG_IDX_WINDOWBASE || reg_idx == XT_REG_IDX_WINDOWSTART)
-               return xtensa->core_config->windowed;
-       else if (reg_idx >= XT_REG_IDX_PTEVADDR && reg_idx <= XT_REG_IDX_DTLBCFG)
-               return xtensa->core_config->mmu.enabled;
-       else if (reg_idx == XT_REG_IDX_MMID)
-               return xtensa->core_config->trace.enabled;
-       else if (reg_idx >= XT_REG_IDX_MEPC && reg_idx <= XT_REG_IDX_MEVADDR)
-               return xtensa->core_config->mem_err_check;
-       else if (reg_idx == XT_REG_IDX_CPENABLE)
-               return xtensa->core_config->coproc;
-       else if (reg_idx == XT_REG_IDX_VECBASE)
-               return xtensa->core_config->reloc_vec;
-       else if (reg_idx == XT_REG_IDX_CCOUNT)
-               return xtensa->core_config->tim_irq.enabled;
-       else if (reg_idx >= XT_REG_IDX_CCOMPARE0 && reg_idx <= XT_REG_IDX_CCOMPARE2)
-               return xtensa->core_config->tim_irq.enabled &&
-                      (reg_idx - XT_REG_IDX_CCOMPARE0 < xtensa->core_config->tim_irq.comp_num);
-       else if (reg_idx == XT_REG_IDX_PRID)
-               return xtensa->core_config->proc_id;
-       else if (reg_idx >= XT_REG_IDX_MISC0 && reg_idx <= XT_REG_IDX_MISC3)
-               return reg_idx - XT_REG_IDX_MISC0 < xtensa->core_config->miscregs_num;
-       return true;
+/* NOTE: Assumes A3 has already been saved */
+int xtensa_window_state_save(struct target *target, uint32_t *woe)
+{
+       struct xtensa *xtensa = target_to_xtensa(target);
+       int woe_dis;
+       uint8_t woe_buf[4];
+
+       if (xtensa->core_config->windowed) {
+               /* Save PS (LX) and disable window overflow exceptions prior to AR save */
+               xtensa_queue_exec_ins(xtensa, XT_INS_RSR(xtensa, XT_SR_PS, XT_REG_A3));
+               xtensa_queue_exec_ins(xtensa, XT_INS_WSR(xtensa, XT_SR_DDR, XT_REG_A3));
+               xtensa_queue_dbg_reg_read(xtensa, NARADR_DDR, woe_buf);
+               int res = jtag_execute_queue();
+               if (res != ERROR_OK) {
+                       LOG_ERROR("Failed to read PS (%d)!", res);
+                       return res;
+               }
+               xtensa_core_status_check(target);
+               *woe = buf_get_u32(woe_buf, 0, 32);
+               woe_dis = *woe & ~XT_PS_WOE_MSK;
+               LOG_DEBUG("Clearing PS.WOE (0x%08" PRIx32 " -> 0x%08" PRIx32 ")", *woe, woe_dis);
+               xtensa_queue_dbg_reg_write(xtensa, NARADR_DDR, woe_dis);
+               xtensa_queue_exec_ins(xtensa, XT_INS_RSR(xtensa, XT_SR_DDR, XT_REG_A3));
+               xtensa_queue_exec_ins(xtensa, XT_INS_WSR(xtensa, XT_SR_PS, XT_REG_A3));
+       }
+       return ERROR_OK;
 }
 
-static bool xtensa_user_reg_exists(struct xtensa *xtensa, enum xtensa_reg_id reg_idx)
+/* NOTE: Assumes A3 has already been saved */
+void xtensa_window_state_restore(struct target *target, uint32_t woe)
 {
-       if (reg_idx == XT_REG_IDX_THREADPTR)
-               return xtensa->core_config->threadptr;
-       if (reg_idx == XT_REG_IDX_FCR || reg_idx == XT_REG_IDX_FSR)
-               return xtensa->core_config->fp_coproc;
-       return false;
+       struct xtensa *xtensa = target_to_xtensa(target);
+       if (xtensa->core_config->windowed) {
+               /* Restore window overflow exception state */
+               xtensa_queue_dbg_reg_write(xtensa, NARADR_DDR, woe);
+               xtensa_queue_exec_ins(xtensa, XT_INS_RSR(xtensa, XT_SR_DDR, XT_REG_A3));
+               xtensa_queue_exec_ins(xtensa, XT_INS_WSR(xtensa, XT_SR_PS, XT_REG_A3));
+               LOG_DEBUG("Restored PS.WOE (0x%08" PRIx32 ")", woe);
+       }
 }
 
-static inline bool xtensa_fp_reg_exists(struct xtensa *xtensa, enum xtensa_reg_id reg_idx)
+static bool xtensa_reg_is_readable(int flags, int cpenable)
 {
-       return xtensa->core_config->fp_coproc;
+       if (flags & XT_REGF_NOREAD)
+               return false;
+       if ((flags & XT_REGF_COPROC0) && (cpenable & BIT(0)) == 0)
+               return false;
+       return true;
 }
 
-static inline bool xtensa_regular_reg_exists(struct xtensa *xtensa, enum xtensa_reg_id reg_idx)
+static bool xtensa_scratch_regs_fixup(struct xtensa *xtensa, struct reg *reg_list, int i, int j, int a_idx, int ar_idx)
 {
-       if (reg_idx >= XT_REG_IDX_AR0 && reg_idx <= XT_REG_IDX_AR63)
-               return reg_idx - XT_REG_IDX_AR0 < xtensa->core_config->aregs_num;
-       return true;
+       int a_name = (a_idx == XT_AR_SCRATCH_A3) ? 3 : 4;
+       if (xtensa->scratch_ars[a_idx].intval && !xtensa->scratch_ars[ar_idx].intval) {
+               LOG_DEBUG("AR conflict: a%d -> ar%d", a_name, j - XT_REG_IDX_AR0);
+               memcpy(reg_list[j].value, reg_list[i].value, sizeof(xtensa_reg_val_t));
+       } else {
+               LOG_DEBUG("AR conflict: ar%d -> a%d", j - XT_REG_IDX_AR0, a_name);
+               memcpy(reg_list[i].value, reg_list[j].value, sizeof(xtensa_reg_val_t));
+       }
+       return xtensa->scratch_ars[a_idx].intval && xtensa->scratch_ars[ar_idx].intval;
 }
 
 static int xtensa_write_dirty_registers(struct target *target)
@@ -591,45 +586,50 @@ static int xtensa_write_dirty_registers(struct target *target)
        struct xtensa *xtensa = target_to_xtensa(target);
        int res;
        xtensa_reg_val_t regval, windowbase = 0;
-       bool scratch_reg_dirty = false;
+       bool scratch_reg_dirty = false, delay_cpenable = false;
        struct reg *reg_list = xtensa->core_cache->reg_list;
+       unsigned int reg_list_size = xtensa->core_cache->num_regs;
+       bool preserve_a3 = false;
+       uint8_t a3_buf[4];
+       xtensa_reg_val_t a3, woe;
 
        LOG_TARGET_DEBUG(target, "start");
 
-       /*We need to write the dirty registers in the cache list back to the processor.
-        *Start by writing the SFR/user registers. */
-       for (unsigned int i = 0; i < XT_NUM_REGS; i++) {
+       /* We need to write the dirty registers in the cache list back to the processor.
+        * Start by writing the SFR/user registers. */
+       for (unsigned int i = 0; i < reg_list_size; i++) {
+               struct xtensa_reg_desc *rlist = (i < XT_NUM_REGS) ? xtensa_regs : xtensa->optregs;
+               unsigned int ridx = (i < XT_NUM_REGS) ? i : i - XT_NUM_REGS;
                if (reg_list[i].dirty) {
-                       if (xtensa_regs[i].type == XT_REG_SPECIAL ||
-                               xtensa_regs[i].type == XT_REG_USER ||
-                               xtensa_regs[i].type == XT_REG_FR) {
+                       if (rlist[ridx].type == XT_REG_SPECIAL ||
+                               rlist[ridx].type == XT_REG_USER ||
+                               rlist[ridx].type == XT_REG_FR) {
                                scratch_reg_dirty = true;
+                               if (i == XT_REG_IDX_CPENABLE) {
+                                       delay_cpenable = true;
+                                       continue;
+                               }
                                regval = xtensa_reg_get(target, i);
-                               LOG_TARGET_DEBUG(target, "Writing back reg %s val %08" PRIX32,
-                                       xtensa_regs[i].name,
+                               LOG_TARGET_DEBUG(target, "Writing back reg %s (%d) val %08" PRIX32,
+                                       reg_list[i].name,
+                                       rlist[ridx].reg_num,
                                        regval);
                                xtensa_queue_dbg_reg_write(xtensa, NARADR_DDR, regval);
-                               xtensa_queue_exec_ins(xtensa, XT_INS_RSR(XT_SR_DDR, XT_REG_A3));
-                               if (xtensa_regs[i].type == XT_REG_USER) {
-                                       if (reg_list[i].exist)
-                                               xtensa_queue_exec_ins(xtensa,
-                                                       XT_INS_WUR(xtensa_regs[i].reg_num,
-                                                               XT_REG_A3));
-                               } else if (xtensa_regs[i].type == XT_REG_FR) {
-                                       if (reg_list[i].exist)
-                                               xtensa_queue_exec_ins(xtensa,
-                                                       XT_INS_WFR(xtensa_regs[i].reg_num,
-                                                               XT_REG_A3));
-                               } else {/*SFR */
-                                       if (reg_list[i].exist) {
-                                               unsigned int reg_num = xtensa_regs[i].reg_num;
-                                               if (reg_num == XT_PC_REG_NUM_BASE)
-                                                       /* reg number of PC for debug interrupt
-                                                        * depends on NDEBUGLEVEL */
-                                                       reg_num += xtensa->core_config->debug.irq_level;
-
-                                               xtensa_queue_exec_ins(xtensa,
-                                                       XT_INS_WSR(reg_num, XT_REG_A3));
+                               xtensa_queue_exec_ins(xtensa, XT_INS_RSR(xtensa, XT_SR_DDR, XT_REG_A3));
+                               if (reg_list[i].exist) {
+                                       unsigned int reg_num = rlist[ridx].reg_num;
+                                       if (rlist[ridx].type == XT_REG_USER) {
+                                               xtensa_queue_exec_ins(xtensa, XT_INS_WUR(xtensa, reg_num, XT_REG_A3));
+                                       } else if (rlist[ridx].type == XT_REG_FR) {
+                                               xtensa_queue_exec_ins(xtensa, XT_INS_WFR(xtensa, reg_num, XT_REG_A3));
+                                       } else {/*SFR */
+                                               if (reg_num == XT_PC_REG_NUM_VIRTUAL)
+                                                       /* reg number of PC for debug interrupt depends on NDEBUGLEVEL
+                                                        **/
+                                                       reg_num =
+                                                               (XT_PC_REG_NUM_BASE +
+                                                               xtensa->core_config->debug.irq_level);
+                                               xtensa_queue_exec_ins(xtensa, XT_INS_WSR(xtensa, reg_num, XT_REG_A3));
                                        }
                                }
                                reg_list[i].dirty = false;
@@ -638,31 +638,64 @@ static int xtensa_write_dirty_registers(struct target *target)
        }
        if (scratch_reg_dirty)
                xtensa_mark_register_dirty(xtensa, XT_REG_IDX_A3);
+       if (delay_cpenable) {
+               regval = xtensa_reg_get(target, XT_REG_IDX_CPENABLE);
+               LOG_TARGET_DEBUG(target, "Writing back reg cpenable (224) val %08" PRIX32, regval);
+               xtensa_queue_dbg_reg_write(xtensa, NARADR_DDR, regval);
+               xtensa_queue_exec_ins(xtensa, XT_INS_RSR(xtensa, XT_SR_DDR, XT_REG_A3));
+               xtensa_queue_exec_ins(xtensa, XT_INS_WSR(xtensa,
+                               xtensa_regs[XT_REG_IDX_CPENABLE].reg_num,
+                               XT_REG_A3));
+               reg_list[XT_REG_IDX_CPENABLE].dirty = false;
+       }
 
-       if (xtensa->core_config->user_regs_num > 0 &&
-               xtensa->core_config->queue_write_dirty_user_regs)
-               xtensa->core_config->queue_write_dirty_user_regs(target);
+       preserve_a3 = (xtensa->core_config->windowed);
+       if (preserve_a3) {
+               /* Save (windowed) A3 for scratch use */
+               xtensa_queue_exec_ins(xtensa, XT_INS_WSR(xtensa, XT_SR_DDR, XT_REG_A3));
+               xtensa_queue_dbg_reg_read(xtensa, NARADR_DDR, a3_buf);
+               res = jtag_execute_queue();
+               xtensa_core_status_check(target);
+               a3 = buf_get_u32(a3_buf, 0, 32);
+       }
 
        if (xtensa->core_config->windowed) {
-               /*Grab the windowbase, we need it. */
+               res = xtensa_window_state_save(target, &woe);
+               if (res != ERROR_OK)
+                       return res;
+               /* Grab the windowbase, we need it. */
                windowbase = xtensa_reg_get(target, XT_REG_IDX_WINDOWBASE);
-               /*Check if there are problems with both the ARx as well as the corresponding Rx
-                * registers set and dirty. */
-               /*Warn the user if this happens, not much else we can do... */
+               /* Check if there are mismatches between the ARx and corresponding Ax registers.
+                * When the user sets a register on a windowed config, xt-gdb may set the ARx
+                * register directly.  Thus we take ARx as priority over Ax if both are dirty
+                * and it's unclear if the user set one over the other explicitly.
+                */
                for (unsigned int i = XT_REG_IDX_A0; i <= XT_REG_IDX_A15; i++) {
-                       unsigned int j = xtensa_windowbase_offset_to_canonical(i, windowbase);
+                       unsigned int j = xtensa_windowbase_offset_to_canonical(xtensa, i, windowbase);
                        if (reg_list[i].dirty && reg_list[j].dirty) {
-                               if (memcmp(reg_list[i].value, reg_list[j].value,
-                                               sizeof(xtensa_reg_val_t)) != 0)
-                                       LOG_WARNING(
-                                               "Warning: Both A%d as well as the physical register it points to (AR%d) are dirty and differs in value. Results are undefined!",
-                                               i - XT_REG_IDX_A0,
-                                               j - XT_REG_IDX_AR0);
+                               if (memcmp(reg_list[i].value, reg_list[j].value, sizeof(xtensa_reg_val_t)) != 0) {
+                                       bool show_warning = true;
+                                       if (i == XT_REG_IDX_A3)
+                                               show_warning = xtensa_scratch_regs_fixup(xtensa,
+                                                       reg_list, i, j, XT_AR_SCRATCH_A3, XT_AR_SCRATCH_AR3);
+                                       else if (i == XT_REG_IDX_A4)
+                                               show_warning = xtensa_scratch_regs_fixup(xtensa,
+                                                       reg_list, i, j, XT_AR_SCRATCH_A4, XT_AR_SCRATCH_AR4);
+                                       if (show_warning)
+                                               LOG_WARNING(
+                                                       "Warning: Both A%d [0x%08" PRIx32
+                                                       "] as well as its underlying physical register "
+                                                       "(AR%d) [0x%08" PRIx32 "] are dirty and differ in value",
+                                                       i - XT_REG_IDX_A0,
+                                                       buf_get_u32(reg_list[i].value, 0, 32),
+                                                       j - XT_REG_IDX_AR0,
+                                                       buf_get_u32(reg_list[j].value, 0, 32));
+                               }
                        }
                }
        }
 
-       /*Write A0-A16 */
+       /* Write A0-A16. */
        for (unsigned int i = 0; i < 16; i++) {
                if (reg_list[XT_REG_IDX_A0 + i].dirty) {
                        regval = xtensa_reg_get(target, XT_REG_IDX_A0 + i);
@@ -671,21 +704,25 @@ static int xtensa_write_dirty_registers(struct target *target)
                                regval,
                                xtensa_regs[XT_REG_IDX_A0 + i].reg_num);
                        xtensa_queue_dbg_reg_write(xtensa, NARADR_DDR, regval);
-                       xtensa_queue_exec_ins(xtensa, XT_INS_RSR(XT_SR_DDR, i));
+                       xtensa_queue_exec_ins(xtensa, XT_INS_RSR(xtensa, XT_SR_DDR, i));
                        reg_list[XT_REG_IDX_A0 + i].dirty = false;
+                       if (i == 3) {
+                               /* Avoid stomping A3 during restore at end of function */
+                               a3 = regval;
+                       }
                }
        }
 
        if (xtensa->core_config->windowed) {
-               /*Now write AR0-AR63. */
-               for (unsigned int j = 0; j < 64; j += 16) {
-                       /*Write the 16 registers we can see */
+               /* Now write AR registers */
+               for (unsigned int j = 0; j < XT_REG_IDX_ARLAST; j += 16) {
+                       /* Write the 16 registers we can see */
                        for (unsigned int i = 0; i < 16; i++) {
                                if (i + j < xtensa->core_config->aregs_num) {
                                        enum xtensa_reg_id realadr =
-                                               xtensa_windowbase_offset_to_canonical(XT_REG_IDX_AR0 + i + j,
+                                               xtensa_windowbase_offset_to_canonical(xtensa, XT_REG_IDX_AR0 + i + j,
                                                windowbase);
-                                       /*Write back any dirty un-windowed registers */
+                                       /* Write back any dirty un-windowed registers */
                                        if (reg_list[realadr].dirty) {
                                                regval = xtensa_reg_get(target, realadr);
                                                LOG_TARGET_DEBUG(
@@ -696,53 +733,36 @@ static int xtensa_write_dirty_registers(struct target *target)
                                                        xtensa_regs[realadr].reg_num);
                                                xtensa_queue_dbg_reg_write(xtensa, NARADR_DDR, regval);
                                                xtensa_queue_exec_ins(xtensa,
-                                                       XT_INS_RSR(XT_SR_DDR, xtensa_regs[XT_REG_IDX_AR0 + i].reg_num));
+                                                       XT_INS_RSR(xtensa, XT_SR_DDR,
+                                                               xtensa_regs[XT_REG_IDX_AR0 + i].reg_num));
                                                reg_list[realadr].dirty = false;
+                                               if ((i + j) == 3)
+                                                       /* Avoid stomping AR during A3 restore at end of function */
+                                                       a3 = regval;
                                        }
                                }
                        }
                        /*Now rotate the window so we'll see the next 16 registers. The final rotate
                         * will wraparound, */
                        /*leaving us in the state we were. */
-                       xtensa_queue_exec_ins(xtensa, XT_INS_ROTW(4));
+                       xtensa_queue_exec_ins(xtensa, XT_INS_ROTW(xtensa, 4));
                }
-       }
-       res = jtag_execute_queue();
-       xtensa_core_status_check(target);
 
-       return res;
-}
-
-int xtensa_queue_write_dirty_user_regs_u32(struct target *target)
-{
-       struct xtensa *xtensa = target_to_xtensa(target);
-       struct reg *reg_list = xtensa->core_cache->reg_list;
-       xtensa_reg_val_t reg_val;
-       bool scratch_reg_dirty = false;
+               xtensa_window_state_restore(target, woe);
 
-       LOG_TARGET_DEBUG(target, "start");
+               for (enum xtensa_ar_scratch_set_e s = 0; s < XT_AR_SCRATCH_NUM; s++)
+                       xtensa->scratch_ars[s].intval = false;
+       }
 
-       /* We need to write the dirty registers in the cache list back to the processor.
-        * Start by writing the SFR/user registers. */
-       for (unsigned int i = 0; i < xtensa->core_config->user_regs_num; i++) {
-               if (!reg_list[XT_USR_REG_START + i].dirty)
-                       continue;
-               scratch_reg_dirty = true;
-               reg_val = xtensa_reg_get(target, XT_USR_REG_START + i);
-               LOG_TARGET_DEBUG(target, "Writing back reg %s val %08" PRIX32,
-                       xtensa->core_config->user_regs[i].name,
-                       reg_val);
-               xtensa_queue_dbg_reg_write(xtensa, NARADR_DDR, reg_val);
-               xtensa_queue_exec_ins(xtensa, XT_INS_RSR(XT_SR_DDR, XT_REG_A3));
-               xtensa_queue_exec_ins(xtensa,
-                       XT_INS_WUR(xtensa->core_config->user_regs[i].reg_num,
-                               XT_REG_A3));
-               reg_list[XT_USR_REG_START + i].dirty = false;
+       if (preserve_a3) {
+               xtensa_queue_dbg_reg_write(xtensa, NARADR_DDR, a3);
+               xtensa_queue_exec_ins(xtensa, XT_INS_RSR(xtensa, XT_SR_DDR, XT_REG_A3));
        }
-       if (scratch_reg_dirty)
-               xtensa_mark_register_dirty(xtensa, XT_REG_IDX_A3);
 
-       return ERROR_OK;
+       res = jtag_execute_queue();
+       xtensa_core_status_check(target);
+
+       return res;
 }
 
 static inline bool xtensa_is_stopped(struct target *target)
@@ -757,6 +777,12 @@ int xtensa_examine(struct target *target)
        unsigned int cmd = PWRCTL_DEBUGWAKEUP | PWRCTL_MEMWAKEUP | PWRCTL_COREWAKEUP;
 
        LOG_DEBUG("coreid = %d", target->coreid);
+
+       if (xtensa->core_config->core_type == XT_UNDEF) {
+               LOG_ERROR("XTensa core not configured; is xtensa-core-openocd.cfg missing?");
+               return ERROR_FAIL;
+       }
+
        xtensa_queue_pwr_reg_write(xtensa, DMREG_PWRCTL, cmd);
        xtensa_queue_pwr_reg_write(xtensa, DMREG_PWRCTL, cmd | PWRCTL_JTAGDEBUGUSE);
        xtensa_dm_queue_enable(&xtensa->dbg_mod);
@@ -878,7 +904,7 @@ int xtensa_core_status_check(struct target *target)
                        OCDDSR_EXECEXCEPTION | OCDDSR_EXECOVERRUN);
                if (res != ERROR_OK && !xtensa->suppress_dsr_errors)
                        LOG_TARGET_ERROR(target, "clearing DSR failed!");
-               return xtensa->suppress_dsr_errors ? ERROR_OK : ERROR_FAIL;
+               return ERROR_FAIL;
        }
        return ERROR_OK;
 }
@@ -887,7 +913,6 @@ xtensa_reg_val_t xtensa_reg_get(struct target *target, enum xtensa_reg_id reg_id
 {
        struct xtensa *xtensa = target_to_xtensa(target);
        struct reg *reg = &xtensa->core_cache->reg_list[reg_id];
-       assert(reg_id < xtensa->core_cache->num_regs && "Attempt to access non-existing reg!");
        return xtensa_reg_get_value(reg);
 }
 
@@ -895,12 +920,35 @@ void xtensa_reg_set(struct target *target, enum xtensa_reg_id reg_id, xtensa_reg
 {
        struct xtensa *xtensa = target_to_xtensa(target);
        struct reg *reg = &xtensa->core_cache->reg_list[reg_id];
-       assert(reg_id < xtensa->core_cache->num_regs && "Attempt to access non-existing reg!");
        if (xtensa_reg_get_value(reg) == value)
                return;
        xtensa_reg_set_value(reg, value);
 }
 
+/* Set Ax (XT_REG_RELGEN) register along with its underlying ARx (XT_REG_GENERAL) */
+void xtensa_reg_set_deep_relgen(struct target *target, enum xtensa_reg_id a_idx, xtensa_reg_val_t value)
+{
+       struct xtensa *xtensa = target_to_xtensa(target);
+       uint32_t windowbase = (xtensa->core_config->windowed ?
+               xtensa_reg_get(target, XT_REG_IDX_WINDOWBASE) : 0);
+       int ar_idx = xtensa_windowbase_offset_to_canonical(xtensa, a_idx, windowbase);
+       xtensa_reg_set(target, a_idx, value);
+       xtensa_reg_set(target, ar_idx, value);
+}
+
+/* Read cause for entering halted state; return bitmask in DEBUGCAUSE_* format */
+uint32_t xtensa_cause_get(struct target *target)
+{
+       return xtensa_reg_get(target, XT_REG_IDX_DEBUGCAUSE);
+}
+
+void xtensa_cause_clear(struct target *target)
+{
+       struct xtensa *xtensa = target_to_xtensa(target);
+       xtensa_reg_set(target, XT_REG_IDX_DEBUGCAUSE, 0);
+       xtensa->core_cache->reg_list[XT_REG_IDX_DEBUGCAUSE].dirty = false;
+}
+
 int xtensa_assert_reset(struct target *target)
 {
        struct xtensa *xtensa = target_to_xtensa(target);
@@ -940,17 +988,43 @@ int xtensa_deassert_reset(struct target *target)
        return res;
 }
 
+int xtensa_soft_reset_halt(struct target *target)
+{
+       LOG_TARGET_DEBUG(target, "begin");
+       return xtensa_assert_reset(target);
+}
+
 int xtensa_fetch_all_regs(struct target *target)
 {
        struct xtensa *xtensa = target_to_xtensa(target);
        struct reg *reg_list = xtensa->core_cache->reg_list;
-       xtensa_reg_val_t cpenable = 0, windowbase = 0;
-       uint8_t regvals[XT_NUM_REGS][sizeof(xtensa_reg_val_t)];
-       uint8_t dsrs[XT_NUM_REGS][sizeof(xtensa_dsr_t)];
+       unsigned int reg_list_size = xtensa->core_cache->num_regs;
+       xtensa_reg_val_t cpenable = 0, windowbase = 0, a3;
+       uint32_t woe;
+       uint8_t a3_buf[4];
        bool debug_dsrs = !xtensa->regs_fetched || LOG_LEVEL_IS(LOG_LVL_DEBUG);
 
+       union xtensa_reg_val_u *regvals = calloc(reg_list_size, sizeof(*regvals));
+       if (!regvals) {
+               LOG_TARGET_ERROR(target, "unable to allocate memory for regvals!");
+               return ERROR_FAIL;
+       }
+       union xtensa_reg_val_u *dsrs = calloc(reg_list_size, sizeof(*dsrs));
+       if (!dsrs) {
+               LOG_TARGET_ERROR(target, "unable to allocate memory for dsrs!");
+               free(regvals);
+               return ERROR_FAIL;
+       }
+
        LOG_TARGET_DEBUG(target, "start");
 
+       /* Save (windowed) A3 so cache matches physical AR3; A3 usable as scratch */
+       xtensa_queue_exec_ins(xtensa, XT_INS_WSR(xtensa, XT_SR_DDR, XT_REG_A3));
+       xtensa_queue_dbg_reg_read(xtensa, NARADR_DDR, a3_buf);
+       int res = xtensa_window_state_save(target, &woe);
+       if (res != ERROR_OK)
+               goto xtensa_fetch_all_regs_done;
+
        /* Assume the CPU has just halted. We now want to fill the register cache with all the
         * register contents GDB needs. For speed, we pipeline all the read operations, execute them
         * in one go, then sort everything out from the regvals variable. */
@@ -961,176 +1035,178 @@ int xtensa_fetch_all_regs(struct target *target)
                for (unsigned int i = 0; i < 16; i++) {
                        if (i + j < xtensa->core_config->aregs_num) {
                                xtensa_queue_exec_ins(xtensa,
-                                       XT_INS_WSR(XT_SR_DDR, xtensa_regs[XT_REG_IDX_AR0 + i].reg_num));
-                               xtensa_queue_dbg_reg_read(xtensa, NARADR_DDR, regvals[XT_REG_IDX_AR0 + i + j]);
+                                       XT_INS_WSR(xtensa, XT_SR_DDR, xtensa_regs[XT_REG_IDX_AR0 + i].reg_num));
+                               xtensa_queue_dbg_reg_read(xtensa, NARADR_DDR,
+                                       regvals[XT_REG_IDX_AR0 + i + j].buf);
                                if (debug_dsrs)
-                                       xtensa_queue_dbg_reg_read(xtensa, NARADR_DSR, dsrs[XT_REG_IDX_AR0 + i + j]);
+                                       xtensa_queue_dbg_reg_read(xtensa, NARADR_DSR,
+                                               dsrs[XT_REG_IDX_AR0 + i + j].buf);
                        }
                }
-               if (xtensa->core_config->windowed) {
+               if (xtensa->core_config->windowed)
                        /* Now rotate the window so we'll see the next 16 registers. The final rotate
                         * will wraparound, */
                        /* leaving us in the state we were. */
-                       xtensa_queue_exec_ins(xtensa, XT_INS_ROTW(4));
-               }
+                       xtensa_queue_exec_ins(xtensa, XT_INS_ROTW(xtensa, 4));
        }
+       xtensa_window_state_restore(target, woe);
+
        if (xtensa->core_config->coproc) {
-               /* As the very first thing after AREGS, go grab the CPENABLE registers. It indicates
-                * if we can also grab the FP */
-               /* (and theoretically other coprocessor) registers, or if this is a bad thing to do.*/
-               xtensa_queue_exec_ins(xtensa, XT_INS_RSR(xtensa_regs[XT_REG_IDX_CPENABLE].reg_num, XT_REG_A3));
-               xtensa_queue_exec_ins(xtensa, XT_INS_WSR(XT_SR_DDR, XT_REG_A3));
-               xtensa_queue_dbg_reg_read(xtensa, NARADR_DDR, regvals[XT_REG_IDX_CPENABLE]);
+               /* As the very first thing after AREGS, go grab CPENABLE */
+               xtensa_queue_exec_ins(xtensa, XT_INS_RSR(xtensa, xtensa_regs[XT_REG_IDX_CPENABLE].reg_num, XT_REG_A3));
+               xtensa_queue_exec_ins(xtensa, XT_INS_WSR(xtensa, XT_SR_DDR, XT_REG_A3));
+               xtensa_queue_dbg_reg_read(xtensa, NARADR_DDR, regvals[XT_REG_IDX_CPENABLE].buf);
        }
-       int res = jtag_execute_queue();
+       res = jtag_execute_queue();
        if (res != ERROR_OK) {
                LOG_ERROR("Failed to read ARs (%d)!", res);
-               return res;
+               goto xtensa_fetch_all_regs_done;
        }
        xtensa_core_status_check(target);
 
-       if (xtensa->core_config->coproc)
-               cpenable = buf_get_u32(regvals[XT_REG_IDX_CPENABLE], 0, 32);
+       a3 = buf_get_u32(a3_buf, 0, 32);
+
+       if (xtensa->core_config->coproc) {
+               cpenable = buf_get_u32(regvals[XT_REG_IDX_CPENABLE].buf, 0, 32);
+
+               /* Enable all coprocessors (by setting all bits in CPENABLE) so we can read FP and user registers. */
+               xtensa_queue_dbg_reg_write(xtensa, NARADR_DDR, 0xffffffff);
+               xtensa_queue_exec_ins(xtensa, XT_INS_RSR(xtensa, XT_SR_DDR, XT_REG_A3));
+               xtensa_queue_exec_ins(xtensa, XT_INS_WSR(xtensa, xtensa_regs[XT_REG_IDX_CPENABLE].reg_num, XT_REG_A3));
+
+               /* Save CPENABLE; flag dirty later (when regcache updated) so original value is always restored */
+               LOG_TARGET_DEBUG(target, "CPENABLE: was 0x%" PRIx32 ", all enabled", cpenable);
+               xtensa_reg_set(target, XT_REG_IDX_CPENABLE, cpenable);
+       }
        /* We're now free to use any of A0-A15 as scratch registers
         * Grab the SFRs and user registers first. We use A3 as a scratch register. */
-       for (unsigned int i = 0; i < XT_NUM_REGS; i++) {
-               if (xtensa_reg_is_readable(xtensa_regs[i].flags, cpenable) && reg_list[i].exist &&
-                       (xtensa_regs[i].type == XT_REG_SPECIAL ||
-                               xtensa_regs[i].type == XT_REG_USER || xtensa_regs[i].type == XT_REG_FR)) {
-                       if (xtensa_regs[i].type == XT_REG_USER) {
-                               xtensa_queue_exec_ins(xtensa, XT_INS_RUR(xtensa_regs[i].reg_num, XT_REG_A3));
-                       } else if (xtensa_regs[i].type == XT_REG_FR) {
-                               xtensa_queue_exec_ins(xtensa, XT_INS_RFR(xtensa_regs[i].reg_num, XT_REG_A3));
-                       } else {        /*SFR */
-                               unsigned int reg_num = xtensa_regs[i].reg_num;
-                               if (reg_num == XT_PC_REG_NUM_BASE) {
+       for (unsigned int i = 0; i < reg_list_size; i++) {
+               struct xtensa_reg_desc *rlist = (i < XT_NUM_REGS) ? xtensa_regs : xtensa->optregs;
+               unsigned int ridx = (i < XT_NUM_REGS) ? i : i - XT_NUM_REGS;
+               if (xtensa_reg_is_readable(rlist[ridx].flags, cpenable) && rlist[ridx].exist) {
+                       bool reg_fetched = true;
+                       unsigned int reg_num = rlist[ridx].reg_num;
+                       switch (rlist[ridx].type) {
+                       case XT_REG_USER:
+                               xtensa_queue_exec_ins(xtensa, XT_INS_RUR(xtensa, reg_num, XT_REG_A3));
+                               break;
+                       case XT_REG_FR:
+                               xtensa_queue_exec_ins(xtensa, XT_INS_RFR(xtensa, reg_num, XT_REG_A3));
+                               break;
+                       case XT_REG_SPECIAL:
+                               if (reg_num == XT_PC_REG_NUM_VIRTUAL) {
                                        /* reg number of PC for debug interrupt depends on NDEBUGLEVEL */
-                                       reg_num += xtensa->core_config->debug.irq_level;
+                                       reg_num = (XT_PC_REG_NUM_BASE + xtensa->core_config->debug.irq_level);
+                               } else if (reg_num == xtensa_regs[XT_REG_IDX_CPENABLE].reg_num) {
+                                       /* CPENABLE already read/updated; don't re-read */
+                                       reg_fetched = false;
+                                       break;
                                }
-                               xtensa_queue_exec_ins(xtensa, XT_INS_RSR(reg_num, XT_REG_A3));
+                               xtensa_queue_exec_ins(xtensa, XT_INS_RSR(xtensa, reg_num, XT_REG_A3));
+                               break;
+                       default:
+                               reg_fetched = false;
+                       }
+                       if (reg_fetched) {
+                               xtensa_queue_exec_ins(xtensa, XT_INS_WSR(xtensa, XT_SR_DDR, XT_REG_A3));
+                               xtensa_queue_dbg_reg_read(xtensa, NARADR_DDR, regvals[i].buf);
+                               if (debug_dsrs)
+                                       xtensa_queue_dbg_reg_read(xtensa, NARADR_DSR, dsrs[i].buf);
                        }
-                       xtensa_queue_exec_ins(xtensa, XT_INS_WSR(XT_SR_DDR, XT_REG_A3));
-                       xtensa_queue_dbg_reg_read(xtensa, NARADR_DDR, regvals[i]);
-                       if (debug_dsrs)
-                               xtensa_queue_dbg_reg_read(xtensa, NARADR_DSR, dsrs[i]);
                }
        }
        /* Ok, send the whole mess to the CPU. */
        res = jtag_execute_queue();
        if (res != ERROR_OK) {
                LOG_ERROR("Failed to fetch AR regs!");
-               return res;
+               goto xtensa_fetch_all_regs_done;
        }
        xtensa_core_status_check(target);
 
        if (debug_dsrs) {
                /* DSR checking: follows order in which registers are requested. */
-               for (unsigned int i = 0; i < XT_NUM_REGS; i++) {
-                       if (xtensa_reg_is_readable(xtensa_regs[i].flags, cpenable) && reg_list[i].exist &&
-                               (xtensa_regs[i].type == XT_REG_SPECIAL || xtensa_regs[i].type == XT_REG_USER ||
-                                       xtensa_regs[i].type == XT_REG_FR)) {
-                               if (buf_get_u32(dsrs[i], 0, 32) & OCDDSR_EXECEXCEPTION) {
-                                       LOG_ERROR("Exception reading %s!", xtensa_regs[i].name);
-                                       return ERROR_FAIL;
+               for (unsigned int i = 0; i < reg_list_size; i++) {
+                       struct xtensa_reg_desc *rlist = (i < XT_NUM_REGS) ? xtensa_regs : xtensa->optregs;
+                       unsigned int ridx = (i < XT_NUM_REGS) ? i : i - XT_NUM_REGS;
+                       if (xtensa_reg_is_readable(rlist[ridx].flags, cpenable) && rlist[ridx].exist &&
+                               (rlist[ridx].type != XT_REG_DEBUG) &&
+                               (rlist[ridx].type != XT_REG_RELGEN) &&
+                               (rlist[ridx].type != XT_REG_TIE) &&
+                               (rlist[ridx].type != XT_REG_OTHER)) {
+                               if (buf_get_u32(dsrs[i].buf, 0, 32) & OCDDSR_EXECEXCEPTION) {
+                                       LOG_ERROR("Exception reading %s!", reg_list[i].name);
+                                       res = ERROR_FAIL;
+                                       goto xtensa_fetch_all_regs_done;
                                }
                        }
                }
        }
 
-       if (xtensa->core_config->user_regs_num > 0 && xtensa->core_config->fetch_user_regs) {
-               res = xtensa->core_config->fetch_user_regs(target);
-               if (res != ERROR_OK)
-                       return res;
-       }
-
-       if (xtensa->core_config->windowed) {
+       if (xtensa->core_config->windowed)
                /* We need the windowbase to decode the general addresses. */
-               windowbase = buf_get_u32(regvals[XT_REG_IDX_WINDOWBASE], 0, 32);
-       }
+               windowbase = buf_get_u32(regvals[XT_REG_IDX_WINDOWBASE].buf, 0, 32);
        /* Decode the result and update the cache. */
-       for (unsigned int i = 0; i < XT_NUM_REGS; i++) {
-               if (xtensa_reg_is_readable(xtensa_regs[i].flags, cpenable) && reg_list[i].exist) {
-                       if (xtensa_regs[i].type == XT_REG_GENERAL) {
-                               /* TODO: add support for non-windowed configs */
-                               assert(
-                                       xtensa->core_config->windowed &&
-                                       "Regs fetch is not supported for non-windowed configs!");
+       for (unsigned int i = 0; i < reg_list_size; i++) {
+               struct xtensa_reg_desc *rlist = (i < XT_NUM_REGS) ? xtensa_regs : xtensa->optregs;
+               unsigned int ridx = (i < XT_NUM_REGS) ? i : i - XT_NUM_REGS;
+               if (xtensa_reg_is_readable(rlist[ridx].flags, cpenable) && rlist[ridx].exist) {
+                       if ((xtensa->core_config->windowed) && (rlist[ridx].type == XT_REG_GENERAL)) {
                                /* The 64-value general register set is read from (windowbase) on down.
                                 * We need to get the real register address by subtracting windowbase and
                                 * wrapping around. */
-                               int realadr = xtensa_canonical_to_windowbase_offset(i, windowbase);
-                               buf_cpy(regvals[realadr], reg_list[i].value, reg_list[i].size);
-                       } else if (xtensa_regs[i].type == XT_REG_RELGEN) {
-                               buf_cpy(regvals[xtensa_regs[i].reg_num], reg_list[i].value, reg_list[i].size);
+                               enum xtensa_reg_id realadr = xtensa_canonical_to_windowbase_offset(xtensa, i,
+                                       windowbase);
+                               buf_cpy(regvals[realadr].buf, reg_list[i].value, reg_list[i].size);
+                       } else if (rlist[ridx].type == XT_REG_RELGEN) {
+                               buf_cpy(regvals[rlist[ridx].reg_num].buf, reg_list[i].value, reg_list[i].size);
+                               if (xtensa_extra_debug_log) {
+                                       xtensa_reg_val_t regval = buf_get_u32(regvals[rlist[ridx].reg_num].buf, 0, 32);
+                                       LOG_DEBUG("%s = 0x%x", rlist[ridx].name, regval);
+                               }
                        } else {
-                               buf_cpy(regvals[i], reg_list[i].value, reg_list[i].size);
+                               xtensa_reg_val_t regval = buf_get_u32(regvals[i].buf, 0, 32);
+                               bool is_dirty = (i == XT_REG_IDX_CPENABLE);
+                               if (xtensa_extra_debug_log)
+                                       LOG_INFO("Register %s: 0x%X", reg_list[i].name, regval);
+                               xtensa_reg_set(target, i, regval);
+                               reg_list[i].dirty = is_dirty;   /*always do this _after_ xtensa_reg_set! */
                        }
                        reg_list[i].valid = true;
                } else {
-                       reg_list[i].valid = false;
-               }
-       }
-       /* We have used A3 as a scratch register and we will need to write that back. */
-       xtensa_mark_register_dirty(xtensa, XT_REG_IDX_A3);
-       xtensa->regs_fetched = true;
-
-       return ERROR_OK;
-}
-
-int xtensa_fetch_user_regs_u32(struct target *target)
-{
-       struct xtensa *xtensa = target_to_xtensa(target);
-       struct reg *reg_list = xtensa->core_cache->reg_list;
-       xtensa_reg_val_t cpenable = 0;
-       uint8_t regvals[XT_USER_REGS_NUM_MAX][sizeof(xtensa_reg_val_t)];
-       uint8_t dsrs[XT_USER_REGS_NUM_MAX][sizeof(xtensa_dsr_t)];
-       bool debug_dsrs = !xtensa->regs_fetched || LOG_LEVEL_IS(LOG_LVL_DEBUG);
-
-       assert(xtensa->core_config->user_regs_num < XT_USER_REGS_NUM_MAX && "Too many user regs configured!");
-       if (xtensa->core_config->coproc)
-               cpenable = xtensa_reg_get(target, XT_REG_IDX_CPENABLE);
-
-       for (unsigned int i = 0; i < xtensa->core_config->user_regs_num; i++) {
-               if (!xtensa_reg_is_readable(xtensa->core_config->user_regs[i].flags, cpenable))
-                       continue;
-               xtensa_queue_exec_ins(xtensa, XT_INS_RUR(xtensa->core_config->user_regs[i].reg_num, XT_REG_A3));
-               xtensa_queue_exec_ins(xtensa, XT_INS_WSR(XT_SR_DDR, XT_REG_A3));
-               xtensa_queue_dbg_reg_read(xtensa, NARADR_DDR, regvals[i]);
-               if (debug_dsrs)
-                       xtensa_queue_dbg_reg_read(xtensa, NARADR_DSR, dsrs[i]);
-       }
-       /* Ok, send the whole mess to the CPU. */
-       int res = jtag_execute_queue();
-       if (res != ERROR_OK) {
-               LOG_ERROR("Failed to fetch AR regs!");
-               return res;
-       }
-       xtensa_core_status_check(target);
-
-       if (debug_dsrs) {
-               /* DSR checking: follows order in which registers are requested. */
-               for (unsigned int i = 0; i < xtensa->core_config->user_regs_num; i++) {
-                       if (!xtensa_reg_is_readable(xtensa->core_config->user_regs[i].flags, cpenable))
-                               continue;
-                       if (buf_get_u32(dsrs[i], 0, 32) & OCDDSR_EXECEXCEPTION) {
-                               LOG_ERROR("Exception reading %s!", xtensa->core_config->user_regs[i].name);
-                               return ERROR_FAIL;
+                       if ((rlist[ridx].flags & XT_REGF_MASK) == XT_REGF_NOREAD) {
+                               /* Report read-only registers all-zero but valid */
+                               reg_list[i].valid = true;
+                               xtensa_reg_set(target, i, 0);
+                       } else {
+                               reg_list[i].valid = false;
                        }
                }
        }
 
-       for (unsigned int i = 0; i < xtensa->core_config->user_regs_num; i++) {
-               if (xtensa_reg_is_readable(xtensa->core_config->user_regs[i].flags, cpenable)) {
-                       buf_cpy(regvals[i], reg_list[XT_USR_REG_START + i].value, reg_list[XT_USR_REG_START + i].size);
-                       reg_list[XT_USR_REG_START + i].valid = true;
-               } else {
-                       reg_list[XT_USR_REG_START + i].valid = false;
-               }
-       }
-
-       /* We have used A3 as a scratch register and we will need to write that back. */
+       if (xtensa->core_config->windowed) {
+               /* We have used A3 as a scratch register.
+                * Windowed configs: restore A3's AR (XT_REG_GENERAL) and and flag for write-back.
+                */
+               enum xtensa_reg_id ar3_idx = xtensa_windowbase_offset_to_canonical(xtensa, XT_REG_IDX_A3, windowbase);
+               xtensa_reg_set(target, ar3_idx, a3);
+               xtensa_mark_register_dirty(xtensa, ar3_idx);
+
+               /* Reset scratch_ars[] on fetch.  .chrval tracks AR mapping and changes w/ window */
+               sprintf(xtensa->scratch_ars[XT_AR_SCRATCH_AR3].chrval, "ar%d", ar3_idx - XT_REG_IDX_AR0);
+               enum xtensa_reg_id ar4_idx = xtensa_windowbase_offset_to_canonical(xtensa, XT_REG_IDX_A4, windowbase);
+               sprintf(xtensa->scratch_ars[XT_AR_SCRATCH_AR4].chrval, "ar%d", ar4_idx - XT_REG_IDX_AR0);
+               for (enum xtensa_ar_scratch_set_e s = 0; s < XT_AR_SCRATCH_NUM; s++)
+                       xtensa->scratch_ars[s].intval = false;
+       }
+
+       /* We have used A3 (XT_REG_RELGEN) as a scratch register.  Restore and flag for write-back. */
+       xtensa_reg_set(target, XT_REG_IDX_A3, a3);
        xtensa_mark_register_dirty(xtensa, XT_REG_IDX_A3);
-       return ERROR_OK;
+       xtensa->regs_fetched = true;
+xtensa_fetch_all_regs_done:
+       free(regvals);
+       free(dsrs);
+       return res;
 }
 
 int xtensa_get_gdb_reg_list(struct target *target,
@@ -1139,23 +1215,65 @@ int xtensa_get_gdb_reg_list(struct target *target,
        enum target_register_class reg_class)
 {
        struct xtensa *xtensa = target_to_xtensa(target);
-       unsigned int num_regs = xtensa->core_config->gdb_general_regs_num;
+       unsigned int num_regs;
 
-       if (reg_class == REG_CLASS_ALL)
-               num_regs = xtensa->regs_num;
+       if (reg_class == REG_CLASS_GENERAL) {
+               if ((xtensa->genpkt_regs_num == 0) || !xtensa->contiguous_regs_list) {
+                       LOG_ERROR("reg_class %d unhandled; 'xtgregs' not found", reg_class);
+                       return ERROR_FAIL;
+               }
+               num_regs = xtensa->genpkt_regs_num;
+       } else {
+               /* Determine whether to return a contiguous or sparse register map */
+               num_regs = xtensa->regmap_contiguous ? xtensa->total_regs_num : xtensa->dbregs_num;
+       }
 
-       LOG_DEBUG("reg_class=%i, num_regs=%d", reg_class, num_regs);
+       LOG_DEBUG("reg_class=%i, num_regs=%d", (int)reg_class, num_regs);
 
-       *reg_list = malloc(num_regs * sizeof(struct reg *));
+       *reg_list = calloc(num_regs, sizeof(struct reg *));
        if (!*reg_list)
                return ERROR_FAIL;
 
-       for (unsigned int k = 0; k < num_regs; k++) {
-               unsigned int reg_id = xtensa->core_config->gdb_regs_mapping[k];
-               (*reg_list)[k] = &xtensa->core_cache->reg_list[reg_id];
+       *reg_list_size = num_regs;
+       if (xtensa->regmap_contiguous) {
+               assert((num_regs <= xtensa->total_regs_num) && "contiguous regmap size internal error!");
+               for (unsigned int i = 0; i < num_regs; i++)
+                       (*reg_list)[i] = xtensa->contiguous_regs_list[i];
+               return ERROR_OK;
        }
 
-       *reg_list_size = num_regs;
+       for (unsigned int i = 0; i < num_regs; i++)
+               (*reg_list)[i] = (struct reg *)&xtensa->empty_regs[i];
+       unsigned int k = 0;
+       for (unsigned int i = 0; i < xtensa->core_cache->num_regs && k < num_regs; i++) {
+               if (xtensa->core_cache->reg_list[i].exist) {
+                       struct xtensa_reg_desc *rlist = (i < XT_NUM_REGS) ? xtensa_regs : xtensa->optregs;
+                       unsigned int ridx = (i < XT_NUM_REGS) ? i : i - XT_NUM_REGS;
+                       int sparse_idx = rlist[ridx].dbreg_num;
+                       if (i == XT_REG_IDX_PS) {
+                               if (xtensa->eps_dbglevel_idx == 0) {
+                                       LOG_ERROR("eps_dbglevel_idx not set\n");
+                                       return ERROR_FAIL;
+                               }
+                               (*reg_list)[sparse_idx] = &xtensa->core_cache->reg_list[xtensa->eps_dbglevel_idx];
+                               if (xtensa_extra_debug_log)
+                                       LOG_DEBUG("SPARSE GDB reg 0x%x getting EPS%d 0x%x",
+                                               sparse_idx, xtensa->core_config->debug.irq_level,
+                                               xtensa_reg_get_value((*reg_list)[sparse_idx]));
+                       } else if (rlist[ridx].type == XT_REG_RELGEN) {
+                               (*reg_list)[sparse_idx - XT_REG_IDX_ARFIRST] = &xtensa->core_cache->reg_list[i];
+                       } else {
+                               (*reg_list)[sparse_idx] = &xtensa->core_cache->reg_list[i];
+                       }
+                       if (i == XT_REG_IDX_PC)
+                               /* Make a duplicate copy of PC for external access */
+                               (*reg_list)[XT_PC_DBREG_NUM_BASE] = &xtensa->core_cache->reg_list[i];
+                       k++;
+               }
+       }
+
+       if (k == num_regs)
+               LOG_ERROR("SPARSE GDB reg list full (size %d)", k);
 
        return ERROR_OK;
 }
@@ -1219,21 +1337,21 @@ int xtensa_prepare_resume(struct target *target,
        if (address && !current) {
                xtensa_reg_set(target, XT_REG_IDX_PC, address);
        } else {
-               xtensa_reg_val_t cause = xtensa_reg_get(target, XT_REG_IDX_DEBUGCAUSE);
-               if (cause & DEBUGCAUSE_DB) {
+               uint32_t cause = xtensa_cause_get(target);
+               LOG_TARGET_DEBUG(target, "DEBUGCAUSE 0x%x (watchpoint %lu) (break %lu)",
+                       cause, (cause & DEBUGCAUSE_DB), (cause & (DEBUGCAUSE_BI | DEBUGCAUSE_BN)));
+               if (cause & DEBUGCAUSE_DB)
                        /* We stopped due to a watchpoint. We can't just resume executing the
                         * instruction again because */
                        /* that would trigger the watchpoint again. To fix this, we single-step,
                         * which ignores watchpoints. */
                        xtensa_do_step(target, current, address, handle_breakpoints);
-               }
-               if (cause & (DEBUGCAUSE_BI | DEBUGCAUSE_BN)) {
+               if (cause & (DEBUGCAUSE_BI | DEBUGCAUSE_BN))
                        /* We stopped due to a break instruction. We can't just resume executing the
                         * instruction again because */
                        /* that would trigger the break again. To fix this, we single-step, which
                         * ignores break. */
                        xtensa_do_step(target, current, address, handle_breakpoints);
-               }
        }
 
        /* Write back hw breakpoints. Current FreeRTOS SMP code can set a hw breakpoint on an
@@ -1260,7 +1378,7 @@ int xtensa_do_resume(struct target *target)
 
        LOG_TARGET_DEBUG(target, "start");
 
-       xtensa_queue_exec_ins(xtensa, XT_INS_RFDO);
+       xtensa_queue_exec_ins(xtensa, XT_INS_RFDO(xtensa));
        int res = jtag_execute_queue();
        if (res != ERROR_OK) {
                LOG_TARGET_ERROR(target, "Failed to exec RFDO %d!", res);
@@ -1301,18 +1419,19 @@ int xtensa_resume(struct target *target,
 
 static bool xtensa_pc_in_winexc(struct target *target, target_addr_t pc)
 {
+       struct xtensa *xtensa = target_to_xtensa(target);
        uint8_t insn_buf[XT_ISNS_SZ_MAX];
        int err = xtensa_read_buffer(target, pc, sizeof(insn_buf), insn_buf);
        if (err != ERROR_OK)
                return false;
 
        xtensa_insn_t insn = buf_get_u32(insn_buf, 0, 24);
-       xtensa_insn_t masked = insn & XT_INS_L32E_S32E_MASK;
-       if (masked == XT_INS_L32E(0, 0, 0) || masked == XT_INS_S32E(0, 0, 0))
+       xtensa_insn_t masked = insn & XT_INS_L32E_S32E_MASK(xtensa);
+       if (masked == XT_INS_L32E(xtensa, 0, 0, 0) || masked == XT_INS_S32E(xtensa, 0, 0, 0))
                return true;
 
-       masked = insn & XT_INS_RFWO_RFWU_MASK;
-       if (masked == XT_INS_RFWO || masked == XT_INS_RFWU)
+       masked = insn & XT_INS_RFWO_RFWU_MASK(xtensa);
+       if (masked == XT_INS_RFWO(xtensa) || masked == XT_INS_RFWU(xtensa))
                return true;
 
        return false;
@@ -1325,7 +1444,8 @@ int xtensa_do_step(struct target *target, int current, target_addr_t address, in
        const uint32_t icount_val = -2; /* ICOUNT value to load for 1 step */
        xtensa_reg_val_t dbreakc[XT_WATCHPOINTS_NUM_MAX];
        xtensa_reg_val_t icountlvl, cause;
-       xtensa_reg_val_t oldps, newps, oldpc, cur_pc;
+       xtensa_reg_val_t oldps, oldpc, cur_pc;
+       bool ps_lowered = false;
 
        LOG_TARGET_DEBUG(target, "current=%d, address=" TARGET_ADDR_FMT ", handle_breakpoints=%i",
                current, address, handle_breakpoints);
@@ -1335,16 +1455,16 @@ int xtensa_do_step(struct target *target, int current, target_addr_t address, in
                return ERROR_TARGET_NOT_HALTED;
        }
 
-       if (xtensa->core_config->debug.icount_sz != 32) {
-               LOG_TARGET_WARNING(target, "stepping for ICOUNT less then 32 bits is not implemented!");
+       if (xtensa->eps_dbglevel_idx == 0) {
+               LOG_ERROR("eps_dbglevel_idx not set\n");
                return ERROR_FAIL;
        }
 
-       /* Save old ps/pc */
-       oldps = xtensa_reg_get(target, XT_REG_IDX_PS);
+       /* Save old ps (EPS[dbglvl] on LX), pc */
+       oldps = xtensa_reg_get(target, xtensa->eps_dbglevel_idx);
        oldpc = xtensa_reg_get(target, XT_REG_IDX_PC);
 
-       cause = xtensa_reg_get(target, XT_REG_IDX_DEBUGCAUSE);
+       cause = xtensa_cause_get(target);
        LOG_TARGET_DEBUG(target, "oldps=%" PRIx32 ", oldpc=%" PRIx32 " dbg_cause=%" PRIx32 " exc_cause=%" PRIx32,
                oldps,
                oldpc,
@@ -1353,8 +1473,7 @@ int xtensa_do_step(struct target *target, int current, target_addr_t address, in
        if (handle_breakpoints && (cause & (DEBUGCAUSE_BI | DEBUGCAUSE_BN))) {
                /* handle hard-coded SW breakpoints (e.g. syscalls) */
                LOG_TARGET_DEBUG(target, "Increment PC to pass break instruction...");
-               xtensa_reg_set(target, XT_REG_IDX_DEBUGCAUSE, 0);       /* so we don't recurse into the same routine */
-               xtensa->core_cache->reg_list[XT_REG_IDX_DEBUGCAUSE].dirty = false;
+               xtensa_cause_clear(target);     /* so we don't recurse into the same routine */
                /* pretend that we have stepped */
                if (cause & DEBUGCAUSE_BI)
                        xtensa_reg_set(target, XT_REG_IDX_PC, oldpc + 3);       /* PC = PC+3 */
@@ -1363,13 +1482,22 @@ int xtensa_do_step(struct target *target, int current, target_addr_t address, in
                return ERROR_OK;
        }
 
-       /* Xtensa has an ICOUNTLEVEL register which sets the maximum interrupt level at which the
-        * instructions are to be counted while stepping.
-        * For example, if we need to step by 2 instructions, and an interrupt occurs inbetween,
-        * the processor will execute the interrupt, return, and halt after the 2nd instruction.
-        * However, sometimes we don't want the interrupt handlers to be executed at all, while
-        * stepping through the code. In this case (XT_STEPPING_ISR_OFF), PS.INTLEVEL can be raised
-        * to only allow Debug and NMI interrupts.
+       /* Xtensa LX has an ICOUNTLEVEL register which sets the maximum interrupt level
+        * at which the instructions are to be counted while stepping.
+        *
+        * For example, if we need to step by 2 instructions, and an interrupt occurs
+        * in between, the processor will trigger the interrupt and halt after the 2nd
+        * instruction within the interrupt vector and/or handler.
+        *
+        * However, sometimes we don't want the interrupt handlers to be executed at all
+        * while stepping through the code. In this case (XT_STEPPING_ISR_OFF),
+        * ICOUNTLEVEL can be lowered to the executing code's (level + 1) to prevent ISR
+        * code from being counted during stepping.  Note that C exception handlers must
+        * run at level 0 and hence will be counted and stepped into, should one occur.
+        *
+        * TODO: Certain instructions should never be single-stepped and should instead
+        * be emulated (per DUG): RSIL >= DBGLEVEL, RSR/WSR [ICOUNT|ICOUNTLEVEL], and
+        * RFI >= DBGLEVEL.
         */
        if (xtensa->stepping_isr_mode == XT_STEPPING_ISR_OFF) {
                if (!xtensa->core_config->high_irq.enabled) {
@@ -1378,18 +1506,11 @@ int xtensa_do_step(struct target *target, int current, target_addr_t address, in
                                "disabling IRQs while stepping is not implemented w/o high prio IRQs option!");
                        return ERROR_FAIL;
                }
-               /* Mask all interrupts below Debug, i.e. PS.INTLEVEL = DEBUGLEVEL - 1 */
-               xtensa_reg_val_t temp_ps = (oldps & ~0xF) | (xtensa->core_config->debug.irq_level - 1);
-               xtensa_reg_set(target, XT_REG_IDX_PS, temp_ps);
+               /* Update ICOUNTLEVEL accordingly */
+               icountlvl = MIN((oldps & 0xF) + 1, xtensa->core_config->debug.irq_level);
+       } else {
+               icountlvl = xtensa->core_config->debug.irq_level;
        }
-       /* Regardless of ISRs masking mode we need to count instructions at any CINTLEVEL during step.
-           So set `icountlvl` to DEBUGLEVEL.
-           If ISRs are masked they are disabled in PS (see above), so having `icountlvl` set to DEBUGLEVEL
-           will allow to step through any type of the code, e.g. 'high int level' ISR.
-           If ISRs are not masked With `icountlvl` set to DEBUGLEVEL, we can step into any ISR
-           which can happen (enabled in PS).
-       */
-       icountlvl = xtensa->core_config->debug.irq_level;
 
        if (cause & DEBUGCAUSE_DB) {
                /* We stopped due to a watchpoint. We can't just resume executing the instruction again because
@@ -1398,21 +1519,27 @@ int xtensa_do_step(struct target *target, int current, target_addr_t address, in
                LOG_TARGET_DEBUG(
                        target,
                        "Single-stepping to get past instruction that triggered the watchpoint...");
-               xtensa_reg_set(target, XT_REG_IDX_DEBUGCAUSE, 0);       /*so we don't recurse into
-                                                                        * the same routine */
-               xtensa->core_cache->reg_list[XT_REG_IDX_DEBUGCAUSE].dirty = false;
-               /*Save all DBREAKCx registers and set to 0 to disable watchpoints */
+               xtensa_cause_clear(target);     /* so we don't recurse into the same routine */
+               /* Save all DBREAKCx registers and set to 0 to disable watchpoints */
                for (unsigned int slot = 0; slot < xtensa->core_config->debug.dbreaks_num; slot++) {
                        dbreakc[slot] = xtensa_reg_get(target, XT_REG_IDX_DBREAKC0 + slot);
                        xtensa_reg_set(target, XT_REG_IDX_DBREAKC0 + slot, 0);
                }
        }
 
-       if (!handle_breakpoints && (cause & (DEBUGCAUSE_BI | DEBUGCAUSE_BN))) {
+       if (!handle_breakpoints && (cause & (DEBUGCAUSE_BI | DEBUGCAUSE_BN)))
                /* handle normal SW breakpoint */
-               xtensa_reg_set(target, XT_REG_IDX_DEBUGCAUSE, 0);       /*so we don't recurse into
-                                                                        * the same routine */
-               xtensa->core_cache->reg_list[XT_REG_IDX_DEBUGCAUSE].dirty = false;
+               xtensa_cause_clear(target);     /* so we don't recurse into the same routine */
+       if ((oldps & 0xf) >= icountlvl) {
+               /* Lower interrupt level to allow stepping, but flag eps[dbglvl] to be restored */
+               ps_lowered = true;
+               uint32_t newps = (oldps & ~0xf) | (icountlvl - 1);
+               xtensa_reg_set(target, xtensa->eps_dbglevel_idx, newps);
+               LOG_TARGET_DEBUG(target,
+                       "Lowering PS.INTLEVEL to allow stepping: %s <- 0x%08" PRIx32 " (was 0x%08" PRIx32 ")",
+                       xtensa->core_cache->reg_list[xtensa->eps_dbglevel_idx].name,
+                       newps,
+                       oldps);
        }
        do {
                xtensa_reg_set(target, XT_REG_IDX_ICOUNTLEVEL, icountlvl);
@@ -1467,7 +1594,7 @@ int xtensa_do_step(struct target *target, int current, target_addr_t address, in
                        "cur_ps=%" PRIx32 ", cur_pc=%" PRIx32 " dbg_cause=%" PRIx32 " exc_cause=%" PRIx32,
                        xtensa_reg_get(target, XT_REG_IDX_PS),
                        cur_pc,
-                       xtensa_reg_get(target, XT_REG_IDX_DEBUGCAUSE),
+                       xtensa_cause_get(target),
                        xtensa_reg_get(target, XT_REG_IDX_EXCCAUSE));
 
                /* Do not step into WindowOverflow if ISRs are masked.
@@ -1500,12 +1627,11 @@ int xtensa_do_step(struct target *target, int current, target_addr_t address, in
        }
 
        /* Restore int level */
-       /* TODO: Theoretically, this can mess up stepping over an instruction that modifies
-        * ps.intlevel by itself. TODO: Look into this. */
-       if (xtensa->stepping_isr_mode == XT_STEPPING_ISR_OFF) {
-               newps = xtensa_reg_get(target, XT_REG_IDX_PS);
-               newps = (newps & ~0xF) | (oldps & 0xf);
-               xtensa_reg_set(target, XT_REG_IDX_PS, newps);
+       if (ps_lowered) {
+               LOG_DEBUG("Restoring %s after stepping: 0x%08" PRIx32,
+                       xtensa->core_cache->reg_list[xtensa->eps_dbglevel_idx].name,
+                       oldps);
+               xtensa_reg_set(target, xtensa->eps_dbglevel_idx, oldps);
        }
 
        /* write ICOUNTLEVEL back to zero */
@@ -1553,7 +1679,7 @@ static inline target_addr_t xtensa_get_overlap_size(target_addr_t r1_start,
 }
 
 /**
- * Check if the address gets to memory regions, and it's access mode
+ * Check if the address gets to memory regions, and its access mode
  */
 static bool xtensa_memory_op_validate_range(struct xtensa *xtensa, target_addr_t address, size_t size, int access)
 {
@@ -1584,6 +1710,7 @@ int xtensa_read_memory(struct target *target, target_addr_t address, uint32_t si
        target_addr_t addrend_al = ALIGN_UP(address + size * count, 4);
        target_addr_t adr = addrstart_al;
        uint8_t *albuff;
+       bool bswap = xtensa->target->endianness == TARGET_BIG_ENDIAN;
 
        if (target->state != TARGET_HALTED) {
                LOG_TARGET_WARNING(target, "target not halted");
@@ -1613,19 +1740,48 @@ int xtensa_read_memory(struct target *target, target_addr_t address, uint32_t si
        xtensa_mark_register_dirty(xtensa, XT_REG_IDX_A3);
        /* Write start address to A3 */
        xtensa_queue_dbg_reg_write(xtensa, NARADR_DDR, addrstart_al);
-       xtensa_queue_exec_ins(xtensa, XT_INS_RSR(XT_SR_DDR, XT_REG_A3));
+       xtensa_queue_exec_ins(xtensa, XT_INS_RSR(xtensa, XT_SR_DDR, XT_REG_A3));
        /* Now we can safely read data from addrstart_al up to addrend_al into albuff */
-       for (unsigned int i = 0; adr != addrend_al; i += sizeof(uint32_t), adr += sizeof(uint32_t)) {
-               xtensa_queue_exec_ins(xtensa, XT_INS_LDDR32P(XT_REG_A3));
-               xtensa_queue_dbg_reg_read(xtensa, NARADR_DDR, &albuff[i]);
+       if (xtensa->probe_lsddr32p != 0) {
+               xtensa_queue_exec_ins(xtensa, XT_INS_LDDR32P(xtensa, XT_REG_A3));
+               for (unsigned int i = 0; adr != addrend_al; i += sizeof(uint32_t), adr += sizeof(uint32_t))
+                       xtensa_queue_dbg_reg_read(xtensa,
+                               (adr + sizeof(uint32_t) == addrend_al) ? NARADR_DDR : NARADR_DDREXEC,
+                               &albuff[i]);
+       } else {
+               xtensa_mark_register_dirty(xtensa, XT_REG_IDX_A4);
+               for (unsigned int i = 0; adr != addrend_al; i += sizeof(uint32_t), adr += sizeof(uint32_t)) {
+                       xtensa_queue_exec_ins(xtensa, XT_INS_L32I(xtensa, XT_REG_A3, XT_REG_A4, 0));
+                       xtensa_queue_exec_ins(xtensa, XT_INS_WSR(xtensa, XT_SR_DDR, XT_REG_A4));
+                       xtensa_queue_dbg_reg_read(xtensa, NARADR_DDR, &albuff[i]);
+                       xtensa_queue_dbg_reg_write(xtensa, NARADR_DDR, adr + sizeof(uint32_t));
+                       xtensa_queue_exec_ins(xtensa, XT_INS_RSR(xtensa, XT_SR_DDR, XT_REG_A3));
+               }
        }
        int res = jtag_execute_queue();
-       if (res == ERROR_OK)
+       if (res == ERROR_OK) {
+               bool prev_suppress = xtensa->suppress_dsr_errors;
+               xtensa->suppress_dsr_errors = true;
                res = xtensa_core_status_check(target);
-       if (res != ERROR_OK)
-               LOG_TARGET_WARNING(target, "Failed reading %d bytes at address " TARGET_ADDR_FMT,
-                       count * size, address);
+               if (xtensa->probe_lsddr32p == -1)
+                       xtensa->probe_lsddr32p = 1;
+               xtensa->suppress_dsr_errors = prev_suppress;
+       }
+       if (res != ERROR_OK) {
+               if (xtensa->probe_lsddr32p != 0) {
+                       /* Disable fast memory access instructions and retry before reporting an error */
+                       LOG_TARGET_INFO(target, "Disabling LDDR32.P/SDDR32.P");
+                       xtensa->probe_lsddr32p = 0;
+                       res = xtensa_read_memory(target, address, size, count, buffer);
+                       bswap = false;
+               } else {
+                       LOG_TARGET_WARNING(target, "Failed reading %d bytes at address "TARGET_ADDR_FMT,
+                               count * size, address);
+               }
+       }
 
+       if (bswap)
+               buf_bswap32(albuff, albuff, addrend_al - addrstart_al);
        if (albuff != buffer) {
                memcpy(buffer, albuff + (address & 3), (size * count));
                free(albuff);
@@ -1656,6 +1812,7 @@ int xtensa_write_memory(struct target *target,
        target_addr_t adr = addrstart_al;
        int res;
        uint8_t *albuff;
+       bool fill_head_tail = false;
 
        if (target->state != TARGET_HALTED) {
                LOG_TARGET_WARNING(target, "target not halted");
@@ -1674,34 +1831,49 @@ int xtensa_write_memory(struct target *target,
 
        /* Allocate a temporary buffer to put the aligned bytes in, if needed. */
        if (addrstart_al == address && addrend_al == address + (size * count)) {
-               /* We discard the const here because albuff can also be non-const */
-               albuff = (uint8_t *)buffer;
+               if (xtensa->target->endianness == TARGET_BIG_ENDIAN)
+                       /* Need a buffer for byte-swapping */
+                       albuff = malloc(addrend_al - addrstart_al);
+               else
+                       /* We discard the const here because albuff can also be non-const */
+                       albuff = (uint8_t *)buffer;
        } else {
+               fill_head_tail = true;
                albuff = malloc(addrend_al - addrstart_al);
-               if (!albuff) {
-                       LOG_TARGET_ERROR(target, "Out of memory allocating %" TARGET_PRIdADDR " bytes!",
-                               addrend_al - addrstart_al);
-                       return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
-               }
+       }
+       if (!albuff) {
+               LOG_TARGET_ERROR(target, "Out of memory allocating %" TARGET_PRIdADDR " bytes!",
+                       addrend_al - addrstart_al);
+               return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
        }
 
        /* We're going to use A3 here */
        xtensa_mark_register_dirty(xtensa, XT_REG_IDX_A3);
 
        /* If we're using a temp aligned buffer, we need to fill the head and/or tail bit of it. */
-       if (albuff != buffer) {
+       if (fill_head_tail) {
                /* See if we need to read the first and/or last word. */
                if (address & 3) {
                        xtensa_queue_dbg_reg_write(xtensa, NARADR_DDR, addrstart_al);
-                       xtensa_queue_exec_ins(xtensa, XT_INS_RSR(XT_SR_DDR, XT_REG_A3));
-                       xtensa_queue_exec_ins(xtensa, XT_INS_LDDR32P(XT_REG_A3));
+                       xtensa_queue_exec_ins(xtensa, XT_INS_RSR(xtensa, XT_SR_DDR, XT_REG_A3));
+                       if (xtensa->probe_lsddr32p == 1) {
+                               xtensa_queue_exec_ins(xtensa, XT_INS_LDDR32P(xtensa, XT_REG_A3));
+                       } else {
+                               xtensa_queue_exec_ins(xtensa, XT_INS_L32I(xtensa, XT_REG_A3, XT_REG_A3, 0));
+                               xtensa_queue_exec_ins(xtensa, XT_INS_WSR(xtensa, XT_SR_DDR, XT_REG_A3));
+                       }
                        xtensa_queue_dbg_reg_read(xtensa, NARADR_DDR, &albuff[0]);
                }
                if ((address + (size * count)) & 3) {
                        xtensa_queue_dbg_reg_write(xtensa, NARADR_DDR, addrend_al - 4);
-                       xtensa_queue_exec_ins(xtensa, XT_INS_RSR(XT_SR_DDR, XT_REG_A3));
-                       xtensa_queue_exec_ins(xtensa, XT_INS_LDDR32P(XT_REG_A3));
-                       xtensa_queue_dbg_reg_read(xtensa, NARADR_DDR,
+                       xtensa_queue_exec_ins(xtensa, XT_INS_RSR(xtensa, XT_SR_DDR, XT_REG_A3));
+                       if (xtensa->probe_lsddr32p == 1) {
+                               xtensa_queue_exec_ins(xtensa, XT_INS_LDDR32P(xtensa, XT_REG_A3));
+                       } else {
+                               xtensa_queue_exec_ins(xtensa, XT_INS_L32I(xtensa, XT_REG_A3, XT_REG_A3, 0));
+                               xtensa_queue_exec_ins(xtensa, XT_INS_WSR(xtensa, XT_SR_DDR, XT_REG_A3));
+                       }
+                       xtensa_queue_dbg_reg_read(xtensa, NARADR_DDR,
                                &albuff[addrend_al - addrstart_al - 4]);
                }
                /* Grab bytes */
@@ -1713,24 +1885,110 @@ int xtensa_write_memory(struct target *target,
                        return res;
                }
                xtensa_core_status_check(target);
-               /* Copy data to be written into the aligned buffer */
+               if (xtensa->target->endianness == TARGET_BIG_ENDIAN) {
+                       bool swapped_w0 = false;
+                       if (address & 3) {
+                               buf_bswap32(&albuff[0], &albuff[0], 4);
+                               swapped_w0 = true;
+                       }
+                       if ((address + (size * count)) & 3) {
+                               if ((addrend_al - addrstart_al - 4 == 0) && swapped_w0) {
+                                       /* Don't double-swap if buffer start/end are within the same word */
+                               } else {
+                                       buf_bswap32(&albuff[addrend_al - addrstart_al - 4],
+                                               &albuff[addrend_al - addrstart_al - 4], 4);
+                               }
+                       }
+               }
+               /* Copy data to be written into the aligned buffer (in host-endianness) */
                memcpy(&albuff[address & 3], buffer, size * count);
                /* Now we can write albuff in aligned uint32s. */
        }
 
+       if (xtensa->target->endianness == TARGET_BIG_ENDIAN)
+               buf_bswap32(albuff, fill_head_tail ? albuff : buffer, addrend_al - addrstart_al);
+
        /* Write start address to A3 */
        xtensa_queue_dbg_reg_write(xtensa, NARADR_DDR, addrstart_al);
-       xtensa_queue_exec_ins(xtensa, XT_INS_RSR(XT_SR_DDR, XT_REG_A3));
+       xtensa_queue_exec_ins(xtensa, XT_INS_RSR(xtensa, XT_SR_DDR, XT_REG_A3));
        /* Write the aligned buffer */
-       for (unsigned int i = 0; adr != addrend_al; i += sizeof(uint32_t), adr += sizeof(uint32_t)) {
-               xtensa_queue_dbg_reg_write(xtensa, NARADR_DDR, buf_get_u32(&albuff[i], 0, 32));
-               xtensa_queue_exec_ins(xtensa, XT_INS_SDDR32P(XT_REG_A3));
+       if (xtensa->probe_lsddr32p != 0) {
+               for (unsigned int i = 0; adr != addrend_al; i += sizeof(uint32_t), adr += sizeof(uint32_t)) {
+                       if (i == 0) {
+                               xtensa_queue_dbg_reg_write(xtensa, NARADR_DDR, buf_get_u32(&albuff[i], 0, 32));
+                               xtensa_queue_exec_ins(xtensa, XT_INS_SDDR32P(xtensa, XT_REG_A3));
+                       } else {
+                               xtensa_queue_dbg_reg_write(xtensa, NARADR_DDREXEC, buf_get_u32(&albuff[i], 0, 32));
+                       }
+               }
+       } else {
+               xtensa_mark_register_dirty(xtensa, XT_REG_IDX_A4);
+               for (unsigned int i = 0; adr != addrend_al; i += sizeof(uint32_t), adr += sizeof(uint32_t)) {
+                       xtensa_queue_dbg_reg_write(xtensa, NARADR_DDR, buf_get_u32(&albuff[i], 0, 32));
+                       xtensa_queue_exec_ins(xtensa, XT_INS_RSR(xtensa, XT_SR_DDR, XT_REG_A4));
+                       xtensa_queue_exec_ins(xtensa, XT_INS_S32I(xtensa, XT_REG_A3, XT_REG_A4, 0));
+                       xtensa_queue_dbg_reg_write(xtensa, NARADR_DDR, adr + sizeof(uint32_t));
+                       xtensa_queue_exec_ins(xtensa, XT_INS_RSR(xtensa, XT_SR_DDR, XT_REG_A3));
+               }
        }
+
        res = jtag_execute_queue();
-       if (res == ERROR_OK)
+       if (res == ERROR_OK) {
+               bool prev_suppress = xtensa->suppress_dsr_errors;
+               xtensa->suppress_dsr_errors = true;
                res = xtensa_core_status_check(target);
-       if (res != ERROR_OK)
-               LOG_TARGET_WARNING(target, "Failed writing %d bytes at address " TARGET_ADDR_FMT, count * size, address);
+               if (xtensa->probe_lsddr32p == -1)
+                       xtensa->probe_lsddr32p = 1;
+               xtensa->suppress_dsr_errors = prev_suppress;
+       }
+       if (res != ERROR_OK) {
+               if (xtensa->probe_lsddr32p != 0) {
+                       /* Disable fast memory access instructions and retry before reporting an error */
+                       LOG_TARGET_INFO(target, "Disabling LDDR32.P/SDDR32.P");
+                       xtensa->probe_lsddr32p = 0;
+                       res = xtensa_write_memory(target, address, size, count, buffer);
+               } else {
+                       LOG_TARGET_WARNING(target, "Failed writing %d bytes at address "TARGET_ADDR_FMT,
+                               count * size, address);
+               }
+       } else {
+               /* Invalidate ICACHE, writeback DCACHE if present */
+               uint32_t issue_ihi = xtensa_is_icacheable(xtensa, address);
+               uint32_t issue_dhwb = xtensa_is_dcacheable(xtensa, address);
+               if (issue_ihi || issue_dhwb) {
+                       uint32_t ilinesize = issue_ihi ?  xtensa->core_config->icache.line_size : UINT32_MAX;
+                       uint32_t dlinesize = issue_dhwb ? xtensa->core_config->dcache.line_size : UINT32_MAX;
+                       uint32_t linesize = MIN(ilinesize, dlinesize);
+                       uint32_t off = 0;
+                       adr = addrstart_al;
+
+                       while ((adr + off) < addrend_al) {
+                               if (off == 0) {
+                                       /* Write start address to A3 */
+                                       xtensa_queue_dbg_reg_write(xtensa, NARADR_DDR, adr);
+                                       xtensa_queue_exec_ins(xtensa, XT_INS_RSR(xtensa, XT_SR_DDR, XT_REG_A3));
+                               }
+                               if (issue_ihi)
+                                       xtensa_queue_exec_ins(xtensa, XT_INS_IHI(xtensa, XT_REG_A3, off));
+                               if (issue_dhwb)
+                                       xtensa_queue_exec_ins(xtensa, XT_INS_DHWBI(xtensa, XT_REG_A3, off));
+                               off += linesize;
+                               if (off > 1020) {
+                                       /* IHI, DHWB have 8-bit immediate operands (0..1020) */
+                                       adr += off;
+                                       off = 0;
+                               }
+                       }
+
+                       /* Execute cache WB/INV instructions */
+                       res = jtag_execute_queue();
+                       xtensa_core_status_check(target);
+                       if (res != ERROR_OK)
+                               LOG_TARGET_ERROR(target,
+                                       "Error issuing cache writeback/invaldate instruction(s): %d",
+                                       res);
+               }
+       }
        if (albuff != buffer)
                free(albuff);
 
@@ -1754,6 +2012,11 @@ int xtensa_poll(struct target *target)
        struct xtensa *xtensa = target_to_xtensa(target);
 
        int res = xtensa_dm_power_status_read(&xtensa->dbg_mod, PWRSTAT_DEBUGWASRESET | PWRSTAT_COREWASRESET);
+       if (xtensa->dbg_mod.power_status.stat != xtensa->dbg_mod.power_status.stath)
+               LOG_TARGET_DEBUG(target, "PWRSTAT: read 0x%08" PRIx32 ", clear 0x%08lx, reread 0x%08" PRIx32,
+                       xtensa->dbg_mod.power_status.stat,
+                       PWRSTAT_DEBUGWASRESET | PWRSTAT_COREWASRESET,
+                       xtensa->dbg_mod.power_status.stath);
        if (res != ERROR_OK)
                return res;
 
@@ -1771,9 +2034,15 @@ int xtensa_poll(struct target *target)
        if (res != ERROR_OK)
                return res;
 
+       uint32_t prev_dsr = xtensa->dbg_mod.core_status.dsr;
        res = xtensa_dm_core_status_read(&xtensa->dbg_mod);
        if (res != ERROR_OK)
                return res;
+       if (prev_dsr != xtensa->dbg_mod.core_status.dsr)
+               LOG_TARGET_DEBUG(target,
+                       "DSR has changed: was 0x%08" PRIx32 " now 0x%08" PRIx32,
+                       prev_dsr,
+                       xtensa->dbg_mod.core_status.dsr);
        if (xtensa->dbg_mod.power_status.stath & PWRSTAT_COREWASRESET) {
                /* if RESET state is persitent  */
                target->state = TARGET_RESET;
@@ -1797,7 +2066,7 @@ int xtensa_poll(struct target *target)
                         * priorities: watchpoint == breakpoint > single step > debug interrupt. */
                        /* Watchpoint and breakpoint events at the same time results in special
                         * debug reason: DBG_REASON_WPTANDBKPT. */
-                       xtensa_reg_val_t halt_cause = xtensa_reg_get(target, XT_REG_IDX_DEBUGCAUSE);
+                       uint32_t halt_cause = xtensa_cause_get(target);
                        /* TODO: Add handling of DBG_REASON_EXC_CATCH */
                        if (halt_cause & DEBUGCAUSE_IC)
                                target->debug_reason = DBG_REASON_SINGLESTEP;
@@ -1809,7 +2078,8 @@ int xtensa_poll(struct target *target)
                        } else if (halt_cause & DEBUGCAUSE_DB) {
                                target->debug_reason = DBG_REASON_WATCHPOINT;
                        }
-                       LOG_TARGET_DEBUG(target, "Target halted, pc=0x%08" PRIX32 ", debug_reason=%08x, oldstate=%08x",
+                       LOG_TARGET_DEBUG(target, "Target halted, pc=0x%08" PRIx32
+                               ", debug_reason=%08" PRIx32 ", oldstate=%08" PRIx32,
                                xtensa_reg_get(target, XT_REG_IDX_PC),
                                target->debug_reason,
                                oldstate);
@@ -1817,8 +2087,6 @@ int xtensa_poll(struct target *target)
                                halt_cause,
                                xtensa_reg_get(target, XT_REG_IDX_EXCCAUSE),
                                xtensa->dbg_mod.core_status.dsr);
-                       LOG_TARGET_INFO(target, "Target halted, PC=0x%08" PRIX32 ", debug_reason=%08x",
-                               xtensa_reg_get(target, XT_REG_IDX_PC), target->debug_reason);
                        xtensa_dm_core_status_clear(
                                &xtensa->dbg_mod,
                                OCDDSR_DEBUGPENDBREAK | OCDDSR_DEBUGINTBREAK | OCDDSR_DEBUGPENDTRAX |
@@ -1852,25 +2120,101 @@ int xtensa_poll(struct target *target)
        return ERROR_OK;
 }
 
+static int xtensa_update_instruction(struct target *target, target_addr_t address, uint32_t size, const uint8_t *buffer)
+{
+       struct xtensa *xtensa = target_to_xtensa(target);
+       unsigned int issue_ihi = xtensa_is_icacheable(xtensa, address);
+       unsigned int issue_dhwbi = xtensa_is_dcacheable(xtensa, address);
+       uint32_t icache_line_size = issue_ihi ? xtensa->core_config->icache.line_size : UINT32_MAX;
+       uint32_t dcache_line_size = issue_dhwbi ? xtensa->core_config->dcache.line_size : UINT32_MAX;
+       unsigned int same_ic_line = ((address & (icache_line_size - 1)) + size) <= icache_line_size;
+       unsigned int same_dc_line = ((address & (dcache_line_size - 1)) + size) <= dcache_line_size;
+       int ret;
+
+       if (size > icache_line_size)
+               return ERROR_FAIL;
+
+       if (issue_ihi || issue_dhwbi) {
+               /* We're going to use A3 here */
+               xtensa_mark_register_dirty(xtensa, XT_REG_IDX_A3);
+
+               /* Write start address to A3 and invalidate */
+               xtensa_queue_dbg_reg_write(xtensa, NARADR_DDR, address);
+               xtensa_queue_exec_ins(xtensa, XT_INS_RSR(xtensa, XT_SR_DDR, XT_REG_A3));
+               LOG_TARGET_DEBUG(target, "DHWBI, IHI for address "TARGET_ADDR_FMT, address);
+               if (issue_dhwbi) {
+                       xtensa_queue_exec_ins(xtensa, XT_INS_DHWBI(xtensa, XT_REG_A3, 0));
+                       if (!same_dc_line) {
+                               LOG_TARGET_DEBUG(target,
+                                       "DHWBI second dcache line for address "TARGET_ADDR_FMT,
+                                       address + 4);
+                               xtensa_queue_exec_ins(xtensa, XT_INS_DHWBI(xtensa, XT_REG_A3, 4));
+                       }
+               }
+               if (issue_ihi) {
+                       xtensa_queue_exec_ins(xtensa, XT_INS_IHI(xtensa, XT_REG_A3, 0));
+                       if (!same_ic_line) {
+                               LOG_TARGET_DEBUG(target,
+                                       "IHI second icache line for address "TARGET_ADDR_FMT,
+                                       address + 4);
+                               xtensa_queue_exec_ins(xtensa, XT_INS_IHI(xtensa, XT_REG_A3, 4));
+                       }
+               }
+
+               /* Execute invalidate instructions */
+               ret = jtag_execute_queue();
+               xtensa_core_status_check(target);
+               if (ret != ERROR_OK) {
+                       LOG_ERROR("Error issuing cache invaldate instruction(s): %d", ret);
+                       return ret;
+               }
+       }
+
+       /* Write new instructions to memory */
+       ret = target_write_buffer(target, address, size, buffer);
+       if (ret != ERROR_OK) {
+               LOG_TARGET_ERROR(target, "Error writing instruction to memory: %d", ret);
+               return ret;
+       }
+
+       if (issue_dhwbi) {
+               /* Flush dcache so instruction propagates.  A3 may be corrupted during memory write */
+               xtensa_queue_dbg_reg_write(xtensa, NARADR_DDR, address);
+               xtensa_queue_exec_ins(xtensa, XT_INS_RSR(xtensa, XT_SR_DDR, XT_REG_A3));
+               xtensa_queue_exec_ins(xtensa, XT_INS_DHWB(xtensa, XT_REG_A3, 0));
+               LOG_DEBUG("DHWB dcache line for address "TARGET_ADDR_FMT, address);
+               if (!same_dc_line) {
+                       LOG_TARGET_DEBUG(target, "DHWB second dcache line for address "TARGET_ADDR_FMT, address + 4);
+                       xtensa_queue_exec_ins(xtensa, XT_INS_DHWB(xtensa, XT_REG_A3, 4));
+               }
+
+               /* Execute invalidate instructions */
+               ret = jtag_execute_queue();
+               xtensa_core_status_check(target);
+       }
+
+       /* TODO: Handle L2 cache if present */
+       return ret;
+}
+
 static int xtensa_sw_breakpoint_add(struct target *target,
        struct breakpoint *breakpoint,
        struct xtensa_sw_breakpoint *sw_bp)
 {
+       struct xtensa *xtensa = target_to_xtensa(target);
        int ret = target_read_buffer(target, breakpoint->address, XT_ISNS_SZ_MAX, sw_bp->insn);
        if (ret != ERROR_OK) {
                LOG_TARGET_ERROR(target, "Failed to read original instruction (%d)!", ret);
                return ret;
        }
 
-       sw_bp->insn_sz = xtensa_insn_size_get(buf_get_u32(sw_bp->insn, 0, 24));
+       sw_bp->insn_sz = MIN(XT_ISNS_SZ_MAX, breakpoint->length);
        sw_bp->oocd_bp = breakpoint;
 
-       uint32_t break_insn = sw_bp->insn_sz == XT_ISNS_SZ_MAX ? XT_INS_BREAK(0, 0) : XT_INS_BREAKN(0);
-       /* convert to target endianness */
-       uint8_t break_insn_buff[4];
-       target_buffer_set_u32(target, break_insn_buff, break_insn);
+       uint32_t break_insn = sw_bp->insn_sz == XT_ISNS_SZ_MAX ? XT_INS_BREAK(xtensa, 0, 0) : XT_INS_BREAKN(xtensa, 0);
 
-       ret = target_write_buffer(target, breakpoint->address, sw_bp->insn_sz, break_insn_buff);
+       /* Underlying memory write will convert instruction endianness, don't do that here */
+       ret = xtensa_update_instruction(target, breakpoint->address, sw_bp->insn_sz, (uint8_t *)&break_insn);
        if (ret != ERROR_OK) {
                LOG_TARGET_ERROR(target, "Failed to write breakpoint instruction (%d)!", ret);
                return ret;
@@ -1881,9 +2225,9 @@ static int xtensa_sw_breakpoint_add(struct target *target,
 
 static int xtensa_sw_breakpoint_remove(struct target *target, struct xtensa_sw_breakpoint *sw_bp)
 {
-       int ret = target_write_buffer(target, sw_bp->oocd_bp->address, sw_bp->insn_sz, sw_bp->insn);
+       int ret = xtensa_update_instruction(target, sw_bp->oocd_bp->address, sw_bp->insn_sz, sw_bp->insn);
        if (ret != ERROR_OK) {
-               LOG_TARGET_ERROR(target, "Failed to read insn (%d)!", ret);
+               LOG_TARGET_ERROR(target, "Failed to write insn (%d)!", ret);
                return ret;
        }
        sw_bp->oocd_bp = NULL;
@@ -1927,7 +2271,8 @@ int xtensa_breakpoint_add(struct target *target, struct breakpoint *breakpoint)
 
        xtensa->hw_brps[slot] = breakpoint;
        /* We will actually write the breakpoints when we resume the target. */
-       LOG_TARGET_DEBUG(target, "placed HW breakpoint @ " TARGET_ADDR_FMT,
+       LOG_TARGET_DEBUG(target, "placed HW breakpoint %u @ " TARGET_ADDR_FMT,
+               slot,
                breakpoint->address);
 
        return ERROR_OK;
@@ -2049,6 +2394,12 @@ static int xtensa_build_reg_cache(struct target *target)
 {
        struct xtensa *xtensa = target_to_xtensa(target);
        struct reg_cache **cache_p = register_get_last_cache_p(&target->reg_cache);
+       unsigned int last_dbreg_num = 0;
+
+       if (xtensa->core_regs_num + xtensa->num_optregs != xtensa->total_regs_num)
+               LOG_TARGET_WARNING(target, "Register count MISMATCH: %d core regs, %d extended regs; %d expected",
+                       xtensa->core_regs_num, xtensa->num_optregs, xtensa->total_regs_num);
+
        struct reg_cache *reg_cache = calloc(1, sizeof(struct reg_cache));
 
        if (!reg_cache) {
@@ -2057,86 +2408,101 @@ static int xtensa_build_reg_cache(struct target *target)
        }
        reg_cache->name = "Xtensa registers";
        reg_cache->next = NULL;
-       reg_cache->num_regs = XT_NUM_REGS + xtensa->core_config->user_regs_num;
        /* Init reglist */
-       struct reg *reg_list = calloc(reg_cache->num_regs, sizeof(struct reg));
+       unsigned int reg_list_size = XT_NUM_REGS + xtensa->num_optregs;
+       struct reg *reg_list = calloc(reg_list_size, sizeof(struct reg));
        if (!reg_list) {
                LOG_ERROR("Failed to alloc reg list!");
                goto fail;
        }
-       xtensa->regs_num = 0;
-
-       for (unsigned int i = 0; i < XT_NUM_REGS; i++) {
-               reg_list[i].exist = false;
-               if (xtensa_regs[i].type == XT_REG_USER) {
-                       if (xtensa_user_reg_exists(xtensa, i))
-                               reg_list[i].exist = true;
-                       else
-                               LOG_DEBUG("User reg '%s' (%d) does not exist", xtensa_regs[i].name, i);
-               } else if (xtensa_regs[i].type == XT_REG_FR) {
-                       if (xtensa_fp_reg_exists(xtensa, i))
-                               reg_list[i].exist = true;
-                       else
-                               LOG_DEBUG("FP reg '%s' (%d) does not exist", xtensa_regs[i].name, i);
-               } else if (xtensa_regs[i].type == XT_REG_SPECIAL) {
-                       if (xtensa_special_reg_exists(xtensa, i))
-                               reg_list[i].exist = true;
-                       else
-                               LOG_DEBUG("Special reg '%s' (%d) does not exist", xtensa_regs[i].name, i);
-               } else {
-                       if (xtensa_regular_reg_exists(xtensa, i))
-                               reg_list[i].exist = true;
-                       else
-                               LOG_DEBUG("Regular reg '%s' (%d) does not exist", xtensa_regs[i].name, i);
-               }
-               reg_list[i].name = xtensa_regs[i].name;
-               reg_list[i].size = 32;
-               reg_list[i].value = calloc(1, 4 /*XT_REG_LEN*/);/* make Clang Static Analyzer happy */
-               if (!reg_list[i].value) {
-                       LOG_ERROR("Failed to alloc reg list value!");
+       xtensa->dbregs_num = 0;
+       unsigned int didx = 0;
+       for (unsigned int whichlist = 0; whichlist < 2; whichlist++) {
+               struct xtensa_reg_desc *rlist = (whichlist == 0) ? xtensa_regs : xtensa->optregs;
+               unsigned int listsize = (whichlist == 0) ? XT_NUM_REGS : xtensa->num_optregs;
+               for (unsigned int i = 0; i < listsize; i++, didx++) {
+                       reg_list[didx].exist = rlist[i].exist;
+                       reg_list[didx].name = rlist[i].name;
+                       reg_list[didx].size = 32;
+                       reg_list[didx].value = calloc(1, 4 /*XT_REG_LEN*/);     /* make Clang Static Analyzer happy */
+                       if (!reg_list[didx].value) {
+                               LOG_ERROR("Failed to alloc reg list value!");
+                               goto fail;
+                       }
+                       reg_list[didx].dirty = false;
+                       reg_list[didx].valid = false;
+                       reg_list[didx].type = &xtensa_reg_type;
+                       reg_list[didx].arch_info = xtensa;
+                       if (rlist[i].exist && (rlist[i].dbreg_num > last_dbreg_num))
+                               last_dbreg_num = rlist[i].dbreg_num;
+
+                       if (xtensa_extra_debug_log) {
+                               LOG_TARGET_DEBUG(target,
+                                       "POPULATE %-16s list %d exist %d, idx %d, type %d, dbreg_num 0x%04x",
+                                       reg_list[didx].name,
+                                       whichlist,
+                                       reg_list[didx].exist,
+                                       didx,
+                                       rlist[i].type,
+                                       rlist[i].dbreg_num);
+                       }
+               }
+       }
+
+       xtensa->dbregs_num = last_dbreg_num + 1;
+       reg_cache->reg_list = reg_list;
+       reg_cache->num_regs = reg_list_size;
+
+       LOG_TARGET_DEBUG(target, "xtensa->total_regs_num %d reg_list_size %d xtensa->dbregs_num %d",
+               xtensa->total_regs_num, reg_list_size, xtensa->dbregs_num);
+
+       /* Construct empty-register list for handling unknown register requests */
+       xtensa->empty_regs = calloc(xtensa->dbregs_num, sizeof(struct reg));
+       if (!xtensa->empty_regs) {
+               LOG_TARGET_ERROR(target, "ERROR: Out of memory");
+               goto fail;
+       }
+       for (unsigned int i = 0; i < xtensa->dbregs_num; i++) {
+               xtensa->empty_regs[i].name = calloc(8, sizeof(char));
+               if (!xtensa->empty_regs[i].name) {
+                       LOG_TARGET_ERROR(target, "ERROR: Out of memory");
                        goto fail;
                }
-               reg_list[i].dirty = false;
-               reg_list[i].valid = false;
-               reg_list[i].type = &xtensa_reg_type;
-               reg_list[i].arch_info = xtensa;
-               if (reg_list[i].exist)
-                       xtensa->regs_num++;
-       }
-       for (unsigned int i = 0; i < xtensa->core_config->user_regs_num; i++) {
-               reg_list[XT_USR_REG_START + i].exist = true;
-               reg_list[XT_USR_REG_START + i].name = xtensa->core_config->user_regs[i].name;
-               reg_list[XT_USR_REG_START + i].size = xtensa->core_config->user_regs[i].size;
-               reg_list[XT_USR_REG_START + i].value = calloc(1, reg_list[XT_USR_REG_START + i].size / 8);
-               if (!reg_list[XT_USR_REG_START + i].value) {
-                       LOG_ERROR("Failed to alloc user reg list value!");
+               sprintf((char *)xtensa->empty_regs[i].name, "?0x%04x", i);
+               xtensa->empty_regs[i].size = 32;
+               xtensa->empty_regs[i].type = &xtensa_reg_type;
+               xtensa->empty_regs[i].value = calloc(1, 4 /*XT_REG_LEN*/);      /* make Clang Static Analyzer happy */
+               if (!xtensa->empty_regs[i].value) {
+                       LOG_ERROR("Failed to alloc empty reg list value!");
                        goto fail;
                }
-               reg_list[XT_USR_REG_START + i].dirty = false;
-               reg_list[XT_USR_REG_START + i].valid = false;
-               reg_list[XT_USR_REG_START + i].type = xtensa->core_config->user_regs[i].type;
-               reg_list[XT_USR_REG_START + i].arch_info = xtensa;
-               xtensa->regs_num++;
-       }
-       if (xtensa->core_config->gdb_general_regs_num >= xtensa->regs_num) {
-               LOG_ERROR("Regs number less then GDB general regs number!");
-               goto fail;
+               xtensa->empty_regs[i].arch_info = xtensa;
        }
 
-       /* assign GDB reg numbers to registers */
-       for (unsigned int gdb_reg_id = 0; gdb_reg_id < xtensa->regs_num; gdb_reg_id++) {
-               unsigned int reg_id = xtensa->core_config->gdb_regs_mapping[gdb_reg_id];
-               if (reg_id >= reg_cache->num_regs) {
-                       LOG_ERROR("Invalid GDB map!");
+       /* Construct contiguous register list from contiguous descriptor list */
+       if (xtensa->regmap_contiguous && xtensa->contiguous_regs_desc) {
+               xtensa->contiguous_regs_list = calloc(xtensa->total_regs_num, sizeof(struct reg *));
+               if (!xtensa->contiguous_regs_list) {
+                       LOG_TARGET_ERROR(target, "ERROR: Out of memory");
                        goto fail;
                }
-               if (!reg_list[reg_id].exist) {
-                       LOG_ERROR("Non-existing reg in GDB map!");
-                       goto fail;
+               for (unsigned int i = 0; i < xtensa->total_regs_num; i++) {
+                       unsigned int j;
+                       for (j = 0; j < reg_cache->num_regs; j++) {
+                               if (!strcmp(reg_cache->reg_list[j].name, xtensa->contiguous_regs_desc[i]->name)) {
+                                       xtensa->contiguous_regs_list[i] = &(reg_cache->reg_list[j]);
+                                       LOG_TARGET_DEBUG(target,
+                                               "POPULATE contiguous regs list: %-16s, dbreg_num 0x%04x",
+                                               xtensa->contiguous_regs_list[i]->name,
+                                               xtensa->contiguous_regs_desc[i]->dbreg_num);
+                                       break;
+                               }
+                       }
+                       if (j == reg_cache->num_regs)
+                               LOG_TARGET_WARNING(target, "contiguous register %s not found",
+                                       xtensa->contiguous_regs_desc[i]->name);
                }
-               reg_list[reg_id].number = gdb_reg_id;
        }
-       reg_cache->reg_list = reg_list;
 
        xtensa->algo_context_backup = calloc(reg_cache->num_regs, sizeof(void *));
        if (!xtensa->algo_context_backup) {
@@ -2151,7 +2517,6 @@ static int xtensa_build_reg_cache(struct target *target)
                        goto fail;
                }
        }
-
        xtensa->core_cache = reg_cache;
        if (cache_p)
                *cache_p = reg_cache;
@@ -2159,9 +2524,15 @@ static int xtensa_build_reg_cache(struct target *target)
 
 fail:
        if (reg_list) {
-               for (unsigned int i = 0; i < reg_cache->num_regs; i++)
+               for (unsigned int i = 0; i < reg_list_size; i++)
                        free(reg_list[i].value);
-               free(reg_list);
+       }
+       if (xtensa->empty_regs) {
+               for (unsigned int i = 0; i < xtensa->dbregs_num; i++) {
+                       free((void *)xtensa->empty_regs[i].name);
+                       free(xtensa->empty_regs[i].value);
+               }
+               free(xtensa->empty_regs);
        }
        if (xtensa->algo_context_backup) {
                for (unsigned int i = 0; i < reg_cache->num_regs; i++)
@@ -2173,21 +2544,321 @@ fail:
        return ERROR_FAIL;
 }
 
+static int32_t xtensa_gdbqc_parse_exec_tie_ops(struct target *target, char *opstr)
+{
+       struct xtensa *xtensa = target_to_xtensa(target);
+       int32_t status = ERROR_COMMAND_ARGUMENT_INVALID;
+       /* Process op[] list */
+       while (opstr && (*opstr == ':')) {
+               uint8_t ops[32];
+               unsigned int oplen = strtoul(opstr + 1, &opstr, 16);
+               if (oplen > 32) {
+                       LOG_TARGET_ERROR(target, "TIE access instruction too long (%d)\n", oplen);
+                       break;
+               }
+               unsigned int i = 0;
+               while ((i < oplen) && opstr && (*opstr == ':'))
+                       ops[i++] = strtoul(opstr + 1, &opstr, 16);
+               if (i != oplen) {
+                       LOG_TARGET_ERROR(target, "TIE access instruction malformed (%d)\n", i);
+                       break;
+               }
+
+               char insn_buf[128];
+               sprintf(insn_buf, "Exec %d-byte TIE sequence: ", oplen);
+               for (i = 0; i < oplen; i++)
+                       sprintf(insn_buf + strlen(insn_buf), "%02x:", ops[i]);
+               LOG_TARGET_DEBUG(target, "%s", insn_buf);
+               xtensa_queue_exec_ins_wide(xtensa, ops, oplen); /* Handles endian-swap */
+               status = ERROR_OK;
+       }
+       return status;
+}
+
+static int xtensa_gdbqc_qxtreg(struct target *target, const char *packet, char **response_p)
+{
+       struct xtensa *xtensa = target_to_xtensa(target);
+       bool iswrite = (packet[0] == 'Q');
+       enum xtensa_qerr_e error;
+
+       /* Read/write TIE register.  Requires spill location.
+        * qxtreg<num>:<len>:<oplen>:<op[0]>:<...>[:<oplen>:<op[0]>:<...>]
+        * Qxtreg<num>:<len>:<oplen>:<op[0]>:<...>[:<oplen>:<op[0]>:<...>]=<value>
+        */
+       if (!(xtensa->spill_buf)) {
+               LOG_ERROR("Spill location not specified. Try 'target remote <host>:3333 &spill_location0'");
+               error = XT_QERR_FAIL;
+               goto xtensa_gdbqc_qxtreg_fail;
+       }
+
+       char *delim;
+       uint32_t regnum = strtoul(packet + 6, &delim, 16);
+       if (*delim != ':') {
+               LOG_ERROR("Malformed qxtreg packet");
+               error = XT_QERR_INVAL;
+               goto xtensa_gdbqc_qxtreg_fail;
+       }
+       uint32_t reglen = strtoul(delim + 1, &delim, 16);
+       if (*delim != ':') {
+               LOG_ERROR("Malformed qxtreg packet");
+               error = XT_QERR_INVAL;
+               goto xtensa_gdbqc_qxtreg_fail;
+       }
+       uint8_t regbuf[XT_QUERYPKT_RESP_MAX];
+       LOG_DEBUG("TIE reg 0x%08" PRIx32 " %s (%d bytes)", regnum, iswrite ? "write" : "read", reglen);
+       if (reglen * 2 + 1 > XT_QUERYPKT_RESP_MAX) {
+               LOG_ERROR("TIE register too large");
+               error = XT_QERR_MEM;
+               goto xtensa_gdbqc_qxtreg_fail;
+       }
+
+       /* (1) Save spill memory, (1.5) [if write then store value to spill location],
+        * (2) read old a4, (3) write spill address to a4.
+        * NOTE: ensure a4 is restored properly by all error handling logic
+        */
+       unsigned int memop_size = (xtensa->spill_loc & 3) ? 1 : 4;
+       int status = xtensa_read_memory(target, xtensa->spill_loc, memop_size,
+               xtensa->spill_bytes / memop_size, xtensa->spill_buf);
+       if (status != ERROR_OK) {
+               LOG_ERROR("Spill memory save");
+               error = XT_QERR_MEM;
+               goto xtensa_gdbqc_qxtreg_fail;
+       }
+       if (iswrite) {
+               /* Extract value and store in spill memory */
+               unsigned int b = 0;
+               char *valbuf = strchr(delim, '=');
+               if (!(valbuf && (*valbuf == '='))) {
+                       LOG_ERROR("Malformed Qxtreg packet");
+                       error = XT_QERR_INVAL;
+                       goto xtensa_gdbqc_qxtreg_fail;
+               }
+               valbuf++;
+               while (*valbuf && *(valbuf + 1)) {
+                       char bytestr[3] = { 0, 0, 0 };
+                       strncpy(bytestr, valbuf, 2);
+                       regbuf[b++] = strtoul(bytestr, NULL, 16);
+                       valbuf += 2;
+               }
+               if (b != reglen) {
+                       LOG_ERROR("Malformed Qxtreg packet");
+                       error = XT_QERR_INVAL;
+                       goto xtensa_gdbqc_qxtreg_fail;
+               }
+               status = xtensa_write_memory(target, xtensa->spill_loc, memop_size,
+                       reglen / memop_size, regbuf);
+               if (status != ERROR_OK) {
+                       LOG_ERROR("TIE value store");
+                       error = XT_QERR_MEM;
+                       goto xtensa_gdbqc_qxtreg_fail;
+               }
+       }
+       xtensa_reg_val_t orig_a4 = xtensa_reg_get(target, XT_REG_IDX_A4);
+       xtensa_queue_dbg_reg_write(xtensa, NARADR_DDR, xtensa->spill_loc);
+       xtensa_queue_exec_ins(xtensa, XT_INS_RSR(xtensa, XT_SR_DDR, XT_REG_A4));
+
+       int32_t tieop_status = xtensa_gdbqc_parse_exec_tie_ops(target, delim);
+
+       /* Restore a4 but not yet spill memory.  Execute it all... */
+       xtensa_queue_dbg_reg_write(xtensa, NARADR_DDR, orig_a4);
+       xtensa_queue_exec_ins(xtensa, XT_INS_RSR(xtensa, XT_SR_DDR, XT_REG_A4));
+       status = jtag_execute_queue();
+       if (status != ERROR_OK) {
+               LOG_TARGET_ERROR(target, "TIE queue execute: %d\n", status);
+               tieop_status = status;
+       }
+       status = xtensa_core_status_check(target);
+       if (status != ERROR_OK) {
+               LOG_TARGET_ERROR(target, "TIE instr execute: %d\n", status);
+               tieop_status = status;
+       }
+
+       if (tieop_status == ERROR_OK) {
+               if (iswrite) {
+                       /* TIE write succeeded; send OK */
+                       strcpy(*response_p, "OK");
+               } else {
+                       /* TIE read succeeded; copy result from spill memory */
+                       status = xtensa_read_memory(target, xtensa->spill_loc, memop_size, reglen, regbuf);
+                       if (status != ERROR_OK) {
+                               LOG_TARGET_ERROR(target, "TIE result read");
+                               tieop_status = status;
+                       }
+                       unsigned int i;
+                       for (i = 0; i < reglen; i++)
+                               sprintf(*response_p + 2 * i, "%02x", regbuf[i]);
+                       *(*response_p + 2 * i) = '\0';
+                       LOG_TARGET_DEBUG(target, "TIE response: %s", *response_p);
+               }
+       }
+
+       /* Restore spill memory first, then report any previous errors */
+       status = xtensa_write_memory(target, xtensa->spill_loc, memop_size,
+               xtensa->spill_bytes / memop_size, xtensa->spill_buf);
+       if (status != ERROR_OK) {
+               LOG_ERROR("Spill memory restore");
+               error = XT_QERR_MEM;
+               goto xtensa_gdbqc_qxtreg_fail;
+       }
+       if (tieop_status != ERROR_OK) {
+               LOG_ERROR("TIE execution");
+               error = XT_QERR_FAIL;
+               goto xtensa_gdbqc_qxtreg_fail;
+       }
+       return ERROR_OK;
+
+xtensa_gdbqc_qxtreg_fail:
+       strcpy(*response_p, xt_qerr[error].chrval);
+       return xt_qerr[error].intval;
+}
+
+int xtensa_gdb_query_custom(struct target *target, const char *packet, char **response_p)
+{
+       struct xtensa *xtensa = target_to_xtensa(target);
+       enum xtensa_qerr_e error;
+       if (!packet || !response_p) {
+               LOG_TARGET_ERROR(target, "invalid parameter: packet %p response_p %p", packet, response_p);
+               return ERROR_FAIL;
+       }
+
+       *response_p = xtensa->qpkt_resp;
+       if (strncmp(packet, "qxtn", 4) == 0) {
+               strcpy(*response_p, "OpenOCD");
+               return ERROR_OK;
+       } else if (strncasecmp(packet, "qxtgdbversion=", 14) == 0) {
+               return ERROR_OK;
+       } else if ((strncmp(packet, "Qxtsis=", 7) == 0) || (strncmp(packet, "Qxtsds=", 7) == 0)) {
+               /* Confirm host cache params match core .cfg file */
+               struct xtensa_cache_config *cachep = (packet[4] == 'i') ?
+                       &xtensa->core_config->icache : &xtensa->core_config->dcache;
+               unsigned int line_size = 0, size = 0, way_count = 0;
+               sscanf(&packet[7], "%x,%x,%x", &line_size, &size, &way_count);
+               if ((cachep->line_size != line_size) ||
+                       (cachep->size != size) ||
+                       (cachep->way_count != way_count)) {
+                       LOG_TARGET_WARNING(target, "%cCache mismatch; check xtensa-core-XXX.cfg file",
+                               cachep == &xtensa->core_config->icache ? 'I' : 'D');
+               }
+               strcpy(*response_p, "OK");
+               return ERROR_OK;
+       } else if ((strncmp(packet, "Qxtiram=", 8) == 0) || (strncmp(packet, "Qxtirom=", 8) == 0)) {
+               /* Confirm host IRAM/IROM params match core .cfg file */
+               struct xtensa_local_mem_config *memp = (packet[5] == 'a') ?
+                       &xtensa->core_config->iram : &xtensa->core_config->irom;
+               unsigned int base = 0, size = 0, i;
+               char *pkt = (char *)&packet[7];
+               do {
+                       pkt++;
+                       size = strtoul(pkt, &pkt, 16);
+                       pkt++;
+                       base = strtoul(pkt, &pkt, 16);
+                       LOG_TARGET_DEBUG(target, "memcheck: %dB @ 0x%08x", size, base);
+                       for (i = 0; i < memp->count; i++) {
+                               if ((memp->regions[i].base == base) && (memp->regions[i].size == size))
+                                       break;
+                       }
+                       if (i == memp->count) {
+                               LOG_TARGET_WARNING(target, "%s mismatch; check xtensa-core-XXX.cfg file",
+                                       memp == &xtensa->core_config->iram ? "IRAM" : "IROM");
+                               break;
+                       }
+                       for (i = 0; i < 11; i++) {
+                               pkt++;
+                               strtoul(pkt, &pkt, 16);
+                       }
+               } while (pkt && (pkt[0] == ','));
+               strcpy(*response_p, "OK");
+               return ERROR_OK;
+       } else if (strncmp(packet, "Qxtexcmlvl=", 11) == 0) {
+               /* Confirm host EXCM_LEVEL matches core .cfg file */
+               unsigned int excm_level = strtoul(&packet[11], NULL, 0);
+               if (!xtensa->core_config->high_irq.enabled ||
+                       (excm_level != xtensa->core_config->high_irq.excm_level))
+                       LOG_TARGET_WARNING(target, "EXCM_LEVEL mismatch; check xtensa-core-XXX.cfg file");
+               strcpy(*response_p, "OK");
+               return ERROR_OK;
+       } else if ((strncmp(packet, "Qxtl2cs=", 8) == 0) ||
+               (strncmp(packet, "Qxtl2ca=", 8) == 0) ||
+               (strncmp(packet, "Qxtdensity=", 11) == 0)) {
+               strcpy(*response_p, "OK");
+               return ERROR_OK;
+       } else if (strncmp(packet, "Qxtspill=", 9) == 0) {
+               char *delim;
+               uint32_t spill_loc = strtoul(packet + 9, &delim, 16);
+               if (*delim != ':') {
+                       LOG_ERROR("Malformed Qxtspill packet");
+                       error = XT_QERR_INVAL;
+                       goto xtensa_gdb_query_custom_fail;
+               }
+               xtensa->spill_loc = spill_loc;
+               xtensa->spill_bytes = strtoul(delim + 1, NULL, 16);
+               if (xtensa->spill_buf)
+                       free(xtensa->spill_buf);
+               xtensa->spill_buf = calloc(1, xtensa->spill_bytes);
+               if (!xtensa->spill_buf) {
+                       LOG_ERROR("Spill buf alloc");
+                       error = XT_QERR_MEM;
+                       goto xtensa_gdb_query_custom_fail;
+               }
+               LOG_TARGET_DEBUG(target, "Set spill 0x%08" PRIx32 " (%d)", xtensa->spill_loc, xtensa->spill_bytes);
+               strcpy(*response_p, "OK");
+               return ERROR_OK;
+       } else if (strncasecmp(packet, "qxtreg", 6) == 0) {
+               return xtensa_gdbqc_qxtreg(target, packet, response_p);
+       } else if ((strncmp(packet, "qTStatus", 8) == 0) ||
+               (strncmp(packet, "qxtftie", 7) == 0) ||
+               (strncmp(packet, "qxtstie", 7) == 0)) {
+               /* Return empty string to indicate trace, TIE wire debug are unsupported */
+               strcpy(*response_p, "");
+               return ERROR_OK;
+       }
+
+       /* Warn for all other queries, but do not return errors */
+       LOG_TARGET_WARNING(target, "Unknown target-specific query packet: %s", packet);
+       strcpy(*response_p, "");
+       return ERROR_OK;
+
+xtensa_gdb_query_custom_fail:
+       strcpy(*response_p, xt_qerr[error].chrval);
+       return xt_qerr[error].intval;
+}
+
 int xtensa_init_arch_info(struct target *target, struct xtensa *xtensa,
-       const struct xtensa_config *xtensa_config,
        const struct xtensa_debug_module_config *dm_cfg)
 {
        target->arch_info = xtensa;
        xtensa->common_magic = XTENSA_COMMON_MAGIC;
        xtensa->target = target;
-       xtensa->core_config = xtensa_config;
        xtensa->stepping_isr_mode = XT_STEPPING_ISR_ON;
 
-       if (!xtensa->core_config->exc.enabled || !xtensa->core_config->irq.enabled ||
-               !xtensa->core_config->high_irq.enabled || !xtensa->core_config->debug.enabled) {
-               LOG_ERROR("Xtensa configuration does not support debugging!");
+       xtensa->core_config = calloc(1, sizeof(struct xtensa_config));
+       if (!xtensa->core_config) {
+               LOG_ERROR("Xtensa configuration alloc failed\n");
                return ERROR_FAIL;
        }
+
+       /* Default cache settings are disabled with 1 way */
+       xtensa->core_config->icache.way_count = 1;
+       xtensa->core_config->dcache.way_count = 1;
+
+       /* chrval: AR3/AR4 register names will change with window mapping.
+        * intval: tracks whether scratch register was set through gdb P packet.
+        */
+       for (enum xtensa_ar_scratch_set_e s = 0; s < XT_AR_SCRATCH_NUM; s++) {
+               xtensa->scratch_ars[s].chrval = calloc(8, sizeof(char));
+               if (!xtensa->scratch_ars[s].chrval) {
+                       for (enum xtensa_ar_scratch_set_e f = s - 1; s >= 0; s--)
+                               free(xtensa->scratch_ars[f].chrval);
+                       free(xtensa->core_config);
+                       LOG_ERROR("Xtensa scratch AR alloc failed\n");
+                       return ERROR_FAIL;
+               }
+               xtensa->scratch_ars[s].intval = false;
+               sprintf(xtensa->scratch_ars[s].chrval, "%s%d",
+                       ((s == XT_AR_SCRATCH_A3) || (s == XT_AR_SCRATCH_A4)) ? "a" : "ar",
+                       ((s == XT_AR_SCRATCH_A3) || (s == XT_AR_SCRATCH_AR3)) ? 3 : 4);
+       }
+
        return xtensa_dm_init(&xtensa->dbg_mod, dm_cfg);
 }
 
@@ -2201,12 +2872,12 @@ int xtensa_target_init(struct command_context *cmd_ctx, struct target *target)
        struct xtensa *xtensa = target_to_xtensa(target);
 
        xtensa->come_online_probes_num = 3;
-       xtensa->hw_brps = calloc(xtensa->core_config->debug.ibreaks_num, sizeof(struct breakpoint *));
+       xtensa->hw_brps = calloc(XT_HW_IBREAK_MAX_NUM, sizeof(struct breakpoint *));
        if (!xtensa->hw_brps) {
                LOG_ERROR("Failed to alloc memory for HW breakpoints!");
                return ERROR_FAIL;
        }
-       xtensa->hw_wps = calloc(xtensa->core_config->debug.dbreaks_num, sizeof(struct watchpoint *));
+       xtensa->hw_wps = calloc(XT_HW_DBREAK_MAX_NUM, sizeof(struct watchpoint *));
        if (!xtensa->hw_wps) {
                free(xtensa->hw_brps);
                LOG_ERROR("Failed to alloc memory for HW watchpoints!");
@@ -2220,6 +2891,11 @@ int xtensa_target_init(struct command_context *cmd_ctx, struct target *target)
                return ERROR_FAIL;
        }
 
+       xtensa->spill_loc = 0xffffffff;
+       xtensa->spill_bytes = 0;
+       xtensa->spill_buf = NULL;
+       xtensa->probe_lsddr32p = -1;    /* Probe for fast load/store operations */
+
        return xtensa_build_reg_cache(target);
 }
 
@@ -2240,6 +2916,21 @@ static void xtensa_free_reg_cache(struct target *target)
        }
        xtensa->core_cache = NULL;
        xtensa->algo_context_backup = NULL;
+
+       if (xtensa->empty_regs) {
+               for (unsigned int i = 0; i < xtensa->dbregs_num; i++) {
+                       free((void *)xtensa->empty_regs[i].name);
+                       free(xtensa->empty_regs[i].value);
+               }
+               free(xtensa->empty_regs);
+       }
+       xtensa->empty_regs = NULL;
+       if (xtensa->optregs) {
+               for (unsigned int i = 0; i < xtensa->num_optregs; i++)
+                       free((void *)xtensa->optregs[i].name);
+               free(xtensa->optregs);
+       }
+       xtensa->optregs = NULL;
 }
 
 void xtensa_target_deinit(struct target *target)
@@ -2265,6 +2956,13 @@ void xtensa_target_deinit(struct target *target)
        free(xtensa->hw_brps);
        free(xtensa->hw_wps);
        free(xtensa->sw_brps);
+       if (xtensa->spill_buf) {
+               free(xtensa->spill_buf);
+               xtensa->spill_buf = NULL;
+       }
+       for (enum xtensa_ar_scratch_set_e s = 0; s < XT_AR_SCRATCH_NUM; s++)
+               free(xtensa->scratch_ars[s].chrval);
+       free(xtensa->core_config);
 }
 
 const char *xtensa_get_gdb_arch(struct target *target)
@@ -2272,6 +2970,521 @@ const char *xtensa_get_gdb_arch(struct target *target)
        return "xtensa";
 }
 
+/* exe <ascii-encoded hexadecimal instruction bytes> */
+COMMAND_HELPER(xtensa_cmd_exe_do, struct target *target)
+{
+       struct xtensa *xtensa = target_to_xtensa(target);
+
+       if (CMD_ARGC != 1)
+               return ERROR_COMMAND_SYNTAX_ERROR;
+
+       /* Process ascii-encoded hex byte string */
+       const char *parm = CMD_ARGV[0];
+       unsigned int parm_len = strlen(parm);
+       if ((parm_len >= 64) || (parm_len & 1)) {
+               LOG_ERROR("Invalid parameter length (%d): must be even, < 64 characters", parm_len);
+               return ERROR_FAIL;
+       }
+
+       uint8_t ops[32];
+       unsigned int oplen = parm_len / 2;
+       char encoded_byte[3] = { 0, 0, 0 };
+       for (unsigned int i = 0; i < oplen; i++) {
+               encoded_byte[0] = *parm++;
+               encoded_byte[1] = *parm++;
+               ops[i] = strtoul(encoded_byte, NULL, 16);
+       }
+
+       /* GDB must handle state save/restore.
+        * Flush reg cache in case spill location is in an AR
+        * Update CPENABLE only for this execution; later restore cached copy
+        * Keep a copy of exccause in case executed code triggers an exception
+        */
+       int status = xtensa_write_dirty_registers(target);
+       if (status != ERROR_OK) {
+               LOG_ERROR("%s: Failed to write back register cache.", target_name(target));
+               return ERROR_FAIL;
+       }
+       xtensa_reg_val_t exccause = xtensa_reg_get(target, XT_REG_IDX_EXCCAUSE);
+       xtensa_reg_val_t cpenable = xtensa_reg_get(target, XT_REG_IDX_CPENABLE);
+       xtensa_reg_val_t a3 = xtensa_reg_get(target, XT_REG_IDX_A3);
+       xtensa_queue_dbg_reg_write(xtensa, NARADR_DDR, 0xffffffff);
+       xtensa_queue_exec_ins(xtensa, XT_INS_RSR(xtensa, XT_SR_DDR, XT_REG_A3));
+       xtensa_queue_exec_ins(xtensa, XT_INS_WSR(xtensa,
+                       xtensa_regs[XT_REG_IDX_CPENABLE].reg_num, XT_REG_A3));
+       xtensa_queue_dbg_reg_write(xtensa, NARADR_DDR, a3);
+       xtensa_queue_exec_ins(xtensa, XT_INS_RSR(xtensa, XT_SR_DDR, XT_REG_A3));
+
+       /* Queue instruction list and execute everything */
+       LOG_TARGET_DEBUG(target, "execute stub: %s", CMD_ARGV[0]);
+       xtensa_queue_exec_ins_wide(xtensa, ops, oplen); /* Handles endian-swap */
+       status = jtag_execute_queue();
+       if (status != ERROR_OK)
+               LOG_TARGET_ERROR(target, "TIE queue execute: %d\n", status);
+       status = xtensa_core_status_check(target);
+       if (status != ERROR_OK)
+               LOG_TARGET_ERROR(target, "TIE instr execute: %d\n", status);
+
+       /* Reread register cache and restore saved regs after instruction execution */
+       if (xtensa_fetch_all_regs(target) != ERROR_OK)
+               LOG_TARGET_ERROR(target, "%s: Failed to fetch register cache (post-exec).", target_name(target));
+       xtensa_reg_set(target, XT_REG_IDX_EXCCAUSE, exccause);
+       xtensa_reg_set(target, XT_REG_IDX_CPENABLE, cpenable);
+       return status;
+}
+
+COMMAND_HANDLER(xtensa_cmd_exe)
+{
+       return CALL_COMMAND_HANDLER(xtensa_cmd_exe_do, get_current_target(CMD_CTX));
+}
+
+/* xtdef <name> */
+COMMAND_HELPER(xtensa_cmd_xtdef_do, struct xtensa *xtensa)
+{
+       if (CMD_ARGC != 1)
+               return ERROR_COMMAND_SYNTAX_ERROR;
+
+       const char *core_name = CMD_ARGV[0];
+       if (strcasecmp(core_name, "LX") == 0) {
+               xtensa->core_config->core_type = XT_LX;
+       } else {
+               LOG_ERROR("xtdef [LX]\n");
+               return ERROR_COMMAND_SYNTAX_ERROR;
+       }
+       return ERROR_OK;
+}
+
+COMMAND_HANDLER(xtensa_cmd_xtdef)
+{
+       return CALL_COMMAND_HANDLER(xtensa_cmd_xtdef_do,
+               target_to_xtensa(get_current_target(CMD_CTX)));
+}
+
+static inline bool xtensa_cmd_xtopt_legal_val(char *opt, int val, int min, int max)
+{
+       if ((val < min) || (val > max)) {
+               LOG_ERROR("xtopt %s (%d) out of range [%d..%d]\n", opt, val, min, max);
+               return false;
+       }
+       return true;
+}
+
+/* xtopt <name> <value> */
+COMMAND_HELPER(xtensa_cmd_xtopt_do, struct xtensa *xtensa)
+{
+       if (CMD_ARGC != 2)
+               return ERROR_COMMAND_SYNTAX_ERROR;
+
+       const char *opt_name = CMD_ARGV[0];
+       int opt_val = strtol(CMD_ARGV[1], NULL, 0);
+       if (strcasecmp(opt_name, "arnum") == 0) {
+               if (!xtensa_cmd_xtopt_legal_val("arnum", opt_val, 0, 64))
+                       return ERROR_COMMAND_ARGUMENT_INVALID;
+               xtensa->core_config->aregs_num = opt_val;
+       } else if (strcasecmp(opt_name, "windowed") == 0) {
+               if (!xtensa_cmd_xtopt_legal_val("windowed", opt_val, 0, 1))
+                       return ERROR_COMMAND_ARGUMENT_INVALID;
+               xtensa->core_config->windowed = opt_val;
+       } else if (strcasecmp(opt_name, "cpenable") == 0) {
+               if (!xtensa_cmd_xtopt_legal_val("cpenable", opt_val, 0, 1))
+                       return ERROR_COMMAND_ARGUMENT_INVALID;
+               xtensa->core_config->coproc = opt_val;
+       } else if (strcasecmp(opt_name, "exceptions") == 0) {
+               if (!xtensa_cmd_xtopt_legal_val("exceptions", opt_val, 0, 1))
+                       return ERROR_COMMAND_ARGUMENT_INVALID;
+               xtensa->core_config->exceptions = opt_val;
+       } else if (strcasecmp(opt_name, "intnum") == 0) {
+               if (!xtensa_cmd_xtopt_legal_val("intnum", opt_val, 0, 32))
+                       return ERROR_COMMAND_ARGUMENT_INVALID;
+               xtensa->core_config->irq.enabled = (opt_val > 0);
+               xtensa->core_config->irq.irq_num = opt_val;
+       } else if (strcasecmp(opt_name, "hipriints") == 0) {
+               if (!xtensa_cmd_xtopt_legal_val("hipriints", opt_val, 0, 1))
+                       return ERROR_COMMAND_ARGUMENT_INVALID;
+               xtensa->core_config->high_irq.enabled = opt_val;
+       } else if (strcasecmp(opt_name, "excmlevel") == 0) {
+               if (!xtensa_cmd_xtopt_legal_val("excmlevel", opt_val, 1, 6))
+                       return ERROR_COMMAND_ARGUMENT_INVALID;
+               if (!xtensa->core_config->high_irq.enabled) {
+                       LOG_ERROR("xtopt excmlevel requires hipriints\n");
+                       return ERROR_COMMAND_ARGUMENT_INVALID;
+               }
+               xtensa->core_config->high_irq.excm_level = opt_val;
+       } else if (strcasecmp(opt_name, "intlevels") == 0) {
+               if (xtensa->core_config->core_type == XT_LX) {
+                       if (!xtensa_cmd_xtopt_legal_val("intlevels", opt_val, 2, 6))
+                               return ERROR_COMMAND_ARGUMENT_INVALID;
+               } else {
+                       if (!xtensa_cmd_xtopt_legal_val("intlevels", opt_val, 1, 255))
+                               return ERROR_COMMAND_ARGUMENT_INVALID;
+               }
+               if (!xtensa->core_config->high_irq.enabled) {
+                       LOG_ERROR("xtopt intlevels requires hipriints\n");
+                       return ERROR_COMMAND_ARGUMENT_INVALID;
+               }
+               xtensa->core_config->high_irq.level_num = opt_val;
+       } else if (strcasecmp(opt_name, "debuglevel") == 0) {
+               if (xtensa->core_config->core_type == XT_LX) {
+                       if (!xtensa_cmd_xtopt_legal_val("debuglevel", opt_val, 2, 6))
+                               return ERROR_COMMAND_ARGUMENT_INVALID;
+               } else {
+                       if (!xtensa_cmd_xtopt_legal_val("debuglevel", opt_val, 0, 0))
+                               return ERROR_COMMAND_ARGUMENT_INVALID;
+               }
+               xtensa->core_config->debug.enabled = 1;
+               xtensa->core_config->debug.irq_level = opt_val;
+       } else if (strcasecmp(opt_name, "ibreaknum") == 0) {
+               if (!xtensa_cmd_xtopt_legal_val("ibreaknum", opt_val, 0, 2))
+                       return ERROR_COMMAND_ARGUMENT_INVALID;
+               xtensa->core_config->debug.ibreaks_num = opt_val;
+       } else if (strcasecmp(opt_name, "dbreaknum") == 0) {
+               if (!xtensa_cmd_xtopt_legal_val("dbreaknum", opt_val, 0, 2))
+                       return ERROR_COMMAND_ARGUMENT_INVALID;
+               xtensa->core_config->debug.dbreaks_num = opt_val;
+       } else if (strcasecmp(opt_name, "tracemem") == 0) {
+               if (!xtensa_cmd_xtopt_legal_val("tracemem", opt_val, 0, 256 * 1024))
+                       return ERROR_COMMAND_ARGUMENT_INVALID;
+               xtensa->core_config->trace.mem_sz = opt_val;
+               xtensa->core_config->trace.enabled = (opt_val > 0);
+       } else if (strcasecmp(opt_name, "tracememrev") == 0) {
+               if (!xtensa_cmd_xtopt_legal_val("tracememrev", opt_val, 0, 1))
+                       return ERROR_COMMAND_ARGUMENT_INVALID;
+               xtensa->core_config->trace.reversed_mem_access = opt_val;
+       } else if (strcasecmp(opt_name, "perfcount") == 0) {
+               if (!xtensa_cmd_xtopt_legal_val("perfcount", opt_val, 0, 8))
+                       return ERROR_COMMAND_ARGUMENT_INVALID;
+               xtensa->core_config->debug.perfcount_num = opt_val;
+       } else {
+               LOG_WARNING("Unknown xtensa command ignored: \"xtopt %s %s\"", CMD_ARGV[0], CMD_ARGV[1]);
+               return ERROR_OK;
+       }
+
+       return ERROR_OK;
+}
+
+COMMAND_HANDLER(xtensa_cmd_xtopt)
+{
+       return CALL_COMMAND_HANDLER(xtensa_cmd_xtopt_do,
+               target_to_xtensa(get_current_target(CMD_CTX)));
+}
+
+/* xtmem <type> [parameters] */
+COMMAND_HELPER(xtensa_cmd_xtmem_do, struct xtensa *xtensa)
+{
+       struct xtensa_cache_config *cachep = NULL;
+       struct xtensa_local_mem_config *memp = NULL;
+       int mem_access = 0;
+       bool is_dcache = false;
+
+       if (CMD_ARGC == 0) {
+               LOG_ERROR("xtmem <type> [parameters]\n");
+               return ERROR_COMMAND_SYNTAX_ERROR;
+       }
+
+       const char *mem_name = CMD_ARGV[0];
+       if (strcasecmp(mem_name, "icache") == 0) {
+               cachep = &xtensa->core_config->icache;
+       } else if (strcasecmp(mem_name, "dcache") == 0) {
+               cachep = &xtensa->core_config->dcache;
+               is_dcache = true;
+       } else if (strcasecmp(mem_name, "l2cache") == 0) {
+               /* TODO: support L2 cache */
+       } else if (strcasecmp(mem_name, "l2addr") == 0) {
+               /* TODO: support L2 cache */
+       } else if (strcasecmp(mem_name, "iram") == 0) {
+               memp = &xtensa->core_config->iram;
+               mem_access = XT_MEM_ACCESS_READ | XT_MEM_ACCESS_WRITE;
+       } else if (strcasecmp(mem_name, "dram") == 0) {
+               memp = &xtensa->core_config->dram;
+               mem_access = XT_MEM_ACCESS_READ | XT_MEM_ACCESS_WRITE;
+       } else if (strcasecmp(mem_name, "sram") == 0) {
+               memp = &xtensa->core_config->sram;
+               mem_access = XT_MEM_ACCESS_READ | XT_MEM_ACCESS_WRITE;
+       } else if (strcasecmp(mem_name, "irom") == 0) {
+               memp = &xtensa->core_config->irom;
+               mem_access = XT_MEM_ACCESS_READ;
+       } else if (strcasecmp(mem_name, "drom") == 0) {
+               memp = &xtensa->core_config->drom;
+               mem_access = XT_MEM_ACCESS_READ;
+       } else if (strcasecmp(mem_name, "srom") == 0) {
+               memp = &xtensa->core_config->srom;
+               mem_access = XT_MEM_ACCESS_READ;
+       } else {
+               LOG_ERROR("xtmem types: <icache|dcache|l2cache|l2addr|iram|irom|dram|drom|sram|srom>\n");
+               return ERROR_COMMAND_ARGUMENT_INVALID;
+       }
+
+       if (cachep) {
+               if ((CMD_ARGC != 4) && (CMD_ARGC != 5)) {
+                       LOG_ERROR("xtmem <cachetype> <linebytes> <cachebytes> <ways> [writeback]\n");
+                       return ERROR_COMMAND_SYNTAX_ERROR;
+               }
+               cachep->line_size = strtoul(CMD_ARGV[1], NULL, 0);
+               cachep->size = strtoul(CMD_ARGV[2], NULL, 0);
+               cachep->way_count = strtoul(CMD_ARGV[3], NULL, 0);
+               cachep->writeback = ((CMD_ARGC == 5) && is_dcache) ?
+                       strtoul(CMD_ARGV[4], NULL, 0) : 0;
+       } else if (memp) {
+               if (CMD_ARGC != 3) {
+                       LOG_ERROR("xtmem <memtype> <baseaddr> <bytes>\n");
+                       return ERROR_COMMAND_SYNTAX_ERROR;
+               }
+               struct xtensa_local_mem_region_config *memcfgp = &memp->regions[memp->count];
+               memcfgp->base = strtoul(CMD_ARGV[1], NULL, 0);
+               memcfgp->size = strtoul(CMD_ARGV[2], NULL, 0);
+               memcfgp->access = mem_access;
+               memp->count++;
+       }
+
+       return ERROR_OK;
+}
+
+COMMAND_HANDLER(xtensa_cmd_xtmem)
+{
+       return CALL_COMMAND_HANDLER(xtensa_cmd_xtmem_do,
+               target_to_xtensa(get_current_target(CMD_CTX)));
+}
+
+/* xtmpu <num FG seg> <min seg size> <lockable> <executeonly> */
+COMMAND_HELPER(xtensa_cmd_xtmpu_do, struct xtensa *xtensa)
+{
+       if (CMD_ARGC != 4) {
+               LOG_ERROR("xtmpu <num FG seg> <min seg size> <lockable> <executeonly>\n");
+               return ERROR_COMMAND_SYNTAX_ERROR;
+       }
+
+       unsigned int nfgseg = strtoul(CMD_ARGV[0], NULL, 0);
+       unsigned int minsegsize = strtoul(CMD_ARGV[1], NULL, 0);
+       unsigned int lockable = strtoul(CMD_ARGV[2], NULL, 0);
+       unsigned int execonly = strtoul(CMD_ARGV[3], NULL, 0);
+
+       if ((nfgseg > 32)) {
+               LOG_ERROR("<nfgseg> must be within [0..32]\n");
+               return ERROR_COMMAND_ARGUMENT_INVALID;
+       } else if (minsegsize & (minsegsize - 1)) {
+               LOG_ERROR("<minsegsize> must be a power of 2 >= 32\n");
+               return ERROR_COMMAND_ARGUMENT_INVALID;
+       } else if (lockable > 1) {
+               LOG_ERROR("<lockable> must be 0 or 1\n");
+               return ERROR_COMMAND_ARGUMENT_INVALID;
+       } else if (execonly > 1) {
+               LOG_ERROR("<execonly> must be 0 or 1\n");
+               return ERROR_COMMAND_ARGUMENT_INVALID;
+       }
+
+       xtensa->core_config->mpu.enabled = true;
+       xtensa->core_config->mpu.nfgseg = nfgseg;
+       xtensa->core_config->mpu.minsegsize = minsegsize;
+       xtensa->core_config->mpu.lockable = lockable;
+       xtensa->core_config->mpu.execonly = execonly;
+       return ERROR_OK;
+}
+
+COMMAND_HANDLER(xtensa_cmd_xtmpu)
+{
+       return CALL_COMMAND_HANDLER(xtensa_cmd_xtmpu_do,
+               target_to_xtensa(get_current_target(CMD_CTX)));
+}
+
+/* xtmmu <NIREFILLENTRIES> <NDREFILLENTRIES> <IVARWAY56> <DVARWAY56> */
+COMMAND_HELPER(xtensa_cmd_xtmmu_do, struct xtensa *xtensa)
+{
+       if (CMD_ARGC != 2) {
+               LOG_ERROR("xtmmu <NIREFILLENTRIES> <NDREFILLENTRIES>\n");
+               return ERROR_COMMAND_SYNTAX_ERROR;
+       }
+
+       unsigned int nirefillentries = strtoul(CMD_ARGV[0], NULL, 0);
+       unsigned int ndrefillentries = strtoul(CMD_ARGV[1], NULL, 0);
+       if ((nirefillentries != 16) && (nirefillentries != 32)) {
+               LOG_ERROR("<nirefillentries> must be 16 or 32\n");
+               return ERROR_COMMAND_ARGUMENT_INVALID;
+       } else if ((ndrefillentries != 16) && (ndrefillentries != 32)) {
+               LOG_ERROR("<ndrefillentries> must be 16 or 32\n");
+               return ERROR_COMMAND_ARGUMENT_INVALID;
+       }
+
+       xtensa->core_config->mmu.enabled = true;
+       xtensa->core_config->mmu.itlb_entries_count = nirefillentries;
+       xtensa->core_config->mmu.dtlb_entries_count = ndrefillentries;
+       return ERROR_OK;
+}
+
+COMMAND_HANDLER(xtensa_cmd_xtmmu)
+{
+       return CALL_COMMAND_HANDLER(xtensa_cmd_xtmmu_do,
+               target_to_xtensa(get_current_target(CMD_CTX)));
+}
+
+/* xtregs <numregs>
+ * xtreg <regname> <regnum> */
+COMMAND_HELPER(xtensa_cmd_xtreg_do, struct xtensa *xtensa)
+{
+       if (CMD_ARGC == 1) {
+               int32_t numregs = strtoul(CMD_ARGV[0], NULL, 0);
+               if ((numregs <= 0) || (numregs > UINT16_MAX)) {
+                       LOG_ERROR("xtreg <numregs>: Invalid 'numregs' (%d)", numregs);
+                       return ERROR_COMMAND_SYNTAX_ERROR;
+               }
+               if ((xtensa->genpkt_regs_num > 0) && (numregs < (int32_t)xtensa->genpkt_regs_num)) {
+                       LOG_ERROR("xtregs (%d) must be larger than numgenregs (%d) (if xtregfmt specified)",
+                               numregs, xtensa->genpkt_regs_num);
+                       return ERROR_COMMAND_SYNTAX_ERROR;
+               }
+               xtensa->total_regs_num = numregs;
+               xtensa->core_regs_num = 0;
+               xtensa->num_optregs = 0;
+               /* A little more memory than required, but saves a second initialization pass */
+               xtensa->optregs = calloc(xtensa->total_regs_num, sizeof(struct xtensa_reg_desc));
+               if (!xtensa->optregs) {
+                       LOG_ERROR("Failed to allocate xtensa->optregs!");
+                       return ERROR_FAIL;
+               }
+               return ERROR_OK;
+       } else if (CMD_ARGC != 2)
+               return ERROR_COMMAND_SYNTAX_ERROR;
+
+       /* "xtregfmt contiguous" must be specified prior to the first "xtreg" definition
+        * if general register (g-packet) requests or contiguous register maps are supported */
+       if (xtensa->regmap_contiguous && !xtensa->contiguous_regs_desc) {
+               xtensa->contiguous_regs_desc = calloc(xtensa->total_regs_num, sizeof(struct xtensa_reg_desc *));
+               if (!xtensa->contiguous_regs_desc) {
+                       LOG_ERROR("Failed to allocate xtensa->contiguous_regs_desc!");
+                       return ERROR_FAIL;
+               }
+       }
+
+       const char *regname = CMD_ARGV[0];
+       unsigned int regnum = strtoul(CMD_ARGV[1], NULL, 0);
+       if (regnum > UINT16_MAX) {
+               LOG_ERROR("<regnum> must be a 16-bit number");
+               return ERROR_COMMAND_ARGUMENT_INVALID;
+       }
+
+       if ((xtensa->num_optregs + xtensa->core_regs_num) >= xtensa->total_regs_num) {
+               if (xtensa->total_regs_num)
+                       LOG_ERROR("'xtreg %s 0x%04x': Too many registers (%d expected, %d core %d extended)",
+                               regname, regnum,
+                               xtensa->total_regs_num, xtensa->core_regs_num, xtensa->num_optregs);
+               else
+                       LOG_ERROR("'xtreg %s 0x%04x': Number of registers unspecified",
+                               regname, regnum);
+               return ERROR_FAIL;
+       }
+
+       /* Determine whether register belongs in xtensa_regs[] or xtensa->xtensa_spec_regs[] */
+       struct xtensa_reg_desc *rptr = &xtensa->optregs[xtensa->num_optregs];
+       bool is_extended_reg = true;
+       unsigned int ridx;
+       for (ridx = 0; ridx < XT_NUM_REGS; ridx++) {
+               if (strcmp(CMD_ARGV[0], xtensa_regs[ridx].name) == 0) {
+                       /* Flag core register as defined */
+                       rptr = &xtensa_regs[ridx];
+                       xtensa->core_regs_num++;
+                       is_extended_reg = false;
+                       break;
+               }
+       }
+
+       rptr->exist = true;
+       if (is_extended_reg) {
+               /* Register ID, debugger-visible register ID */
+               rptr->name = strdup(CMD_ARGV[0]);
+               rptr->dbreg_num = regnum;
+               rptr->reg_num = (regnum & XT_REG_INDEX_MASK);
+               xtensa->num_optregs++;
+
+               /* Register type */
+               if ((regnum & XT_REG_GENERAL_MASK) == XT_REG_GENERAL_VAL) {
+                       rptr->type = XT_REG_GENERAL;
+               } else if ((regnum & XT_REG_USER_MASK) == XT_REG_USER_VAL) {
+                       rptr->type = XT_REG_USER;
+               } else if ((regnum & XT_REG_FR_MASK) == XT_REG_FR_VAL) {
+                       rptr->type = XT_REG_FR;
+               } else if ((regnum & XT_REG_SPECIAL_MASK) == XT_REG_SPECIAL_VAL) {
+                       rptr->type = XT_REG_SPECIAL;
+               } else if ((regnum & XT_REG_RELGEN_MASK) == XT_REG_RELGEN_VAL) {
+                       /* WARNING: For these registers, regnum points to the
+                        * index of the corresponding ARx registers, NOT to
+                        * the processor register number! */
+                       rptr->type = XT_REG_RELGEN;
+                       rptr->reg_num += XT_REG_IDX_ARFIRST;
+                       rptr->dbreg_num += XT_REG_IDX_ARFIRST;
+               } else if ((regnum & XT_REG_TIE_MASK) != 0) {
+                       rptr->type = XT_REG_TIE;
+               } else {
+                       rptr->type = XT_REG_OTHER;
+               }
+
+               /* Register flags */
+               if ((strcmp(rptr->name, "mmid") == 0) || (strcmp(rptr->name, "eraccess") == 0) ||
+                       (strcmp(rptr->name, "ddr") == 0) || (strcmp(rptr->name, "intset") == 0) ||
+                       (strcmp(rptr->name, "intclear") == 0))
+                       rptr->flags = XT_REGF_NOREAD;
+               else
+                       rptr->flags = 0;
+
+               if ((rptr->reg_num == (XT_PS_REG_NUM_BASE + xtensa->core_config->debug.irq_level)) &&
+                       (xtensa->core_config->core_type == XT_LX) && (rptr->type == XT_REG_SPECIAL)) {
+                       xtensa->eps_dbglevel_idx = XT_NUM_REGS + xtensa->num_optregs - 1;
+                       LOG_DEBUG("Setting PS (%s) index to %d", rptr->name, xtensa->eps_dbglevel_idx);
+               }
+       } else if (strcmp(rptr->name, "cpenable") == 0) {
+               xtensa->core_config->coproc = true;
+       }
+
+       /* Build out list of contiguous registers in specified order */
+       unsigned int running_reg_count = xtensa->num_optregs + xtensa->core_regs_num;
+       if (xtensa->contiguous_regs_desc) {
+               assert((running_reg_count <= xtensa->total_regs_num) && "contiguous register address internal error!");
+               xtensa->contiguous_regs_desc[running_reg_count - 1] = rptr;
+       }
+       if (xtensa_extra_debug_log)
+               LOG_DEBUG("Added %s register %-16s: 0x%04x/0x%02x t%d (%d of %d)",
+                       is_extended_reg ? "config-specific" : "core",
+                       rptr->name, rptr->dbreg_num, rptr->reg_num, rptr->type,
+                       is_extended_reg ? xtensa->num_optregs : ridx,
+                       is_extended_reg ? xtensa->total_regs_num : XT_NUM_REGS);
+       return ERROR_OK;
+}
+
+COMMAND_HANDLER(xtensa_cmd_xtreg)
+{
+       return CALL_COMMAND_HANDLER(xtensa_cmd_xtreg_do,
+               target_to_xtensa(get_current_target(CMD_CTX)));
+}
+
+/* xtregfmt <contiguous|sparse> [numgregs] */
+COMMAND_HELPER(xtensa_cmd_xtregfmt_do, struct xtensa *xtensa)
+{
+       if ((CMD_ARGC == 1) || (CMD_ARGC == 2)) {
+               if (!strcasecmp(CMD_ARGV[0], "sparse")) {
+                       return ERROR_OK;
+               } else if (!strcasecmp(CMD_ARGV[0], "contiguous")) {
+                       xtensa->regmap_contiguous = true;
+                       if (CMD_ARGC == 2) {
+                               unsigned int numgregs = strtoul(CMD_ARGV[1], NULL, 0);
+                               if ((numgregs <= 0) ||
+                                       ((numgregs > xtensa->total_regs_num) &&
+                                               (xtensa->total_regs_num > 0))) {
+                                       LOG_ERROR("xtregfmt: if specified, numgregs (%d) must be <= numregs (%d)",
+                                               numgregs, xtensa->total_regs_num);
+                                       return ERROR_COMMAND_SYNTAX_ERROR;
+                               }
+                               xtensa->genpkt_regs_num = numgregs;
+                       }
+                       return ERROR_OK;
+               }
+       }
+       return ERROR_COMMAND_SYNTAX_ERROR;
+}
+
+COMMAND_HANDLER(xtensa_cmd_xtregfmt)
+{
+       return CALL_COMMAND_HANDLER(xtensa_cmd_xtregfmt_do,
+               target_to_xtensa(get_current_target(CMD_CTX)));
+}
+
 COMMAND_HELPER(xtensa_cmd_permissive_mode_do, struct xtensa *xtensa)
 {
        return CALL_COMMAND_HANDLER(handle_command_parse_bool,
@@ -2422,7 +3635,7 @@ COMMAND_HANDLER(xtensa_cmd_mask_interrupts)
 
 COMMAND_HELPER(xtensa_cmd_smpbreak_do, struct target *target)
 {
-       int res = ERROR_OK;
+       int res;
        uint32_t val = 0;
 
        if (CMD_ARGC >= 1) {
@@ -2455,16 +3668,15 @@ COMMAND_HELPER(xtensa_cmd_smpbreak_do, struct target *target)
        } else {
                struct xtensa *xtensa = target_to_xtensa(target);
                res = xtensa_smpbreak_read(xtensa, &val);
-               if (res == ERROR_OK) {
+               if (res == ERROR_OK)
                        command_print(CMD, "Current bits set:%s%s%s%s",
                                (val & OCDDCR_BREAKINEN) ? " BreakIn" : "",
                                (val & OCDDCR_BREAKOUTEN) ? " BreakOut" : "",
                                (val & OCDDCR_RUNSTALLINEN) ? " RunStallIn" : "",
                                (val & OCDDCR_DEBUGMODEOUTEN) ? " DebugModeOut" : ""
                                );
-               } else {
+               else
                        command_print(CMD, "Failed to get smpbreak config %d", res);
-               }
        }
        return res;
 }
@@ -2653,12 +3865,68 @@ COMMAND_HANDLER(xtensa_cmd_tracedump)
                target_to_xtensa(get_current_target(CMD_CTX)), CMD_ARGV[0]);
 }
 
-const struct command_registration xtensa_command_handlers[] = {
+static const struct command_registration xtensa_any_command_handlers[] = {
+       {
+               .name = "xtdef",
+               .handler = xtensa_cmd_xtdef,
+               .mode = COMMAND_CONFIG,
+               .help = "Configure Xtensa core type",
+               .usage = "<type>",
+       },
+       {
+               .name = "xtopt",
+               .handler = xtensa_cmd_xtopt,
+               .mode = COMMAND_CONFIG,
+               .help = "Configure Xtensa core option",
+               .usage = "<name> <value>",
+       },
+       {
+               .name = "xtmem",
+               .handler = xtensa_cmd_xtmem,
+               .mode = COMMAND_CONFIG,
+               .help = "Configure Xtensa memory/cache option",
+               .usage = "<type> [parameters]",
+       },
+       {
+               .name = "xtmmu",
+               .handler = xtensa_cmd_xtmmu,
+               .mode = COMMAND_CONFIG,
+               .help = "Configure Xtensa MMU option",
+               .usage = "<NIREFILLENTRIES> <NDREFILLENTRIES> <IVARWAY56> <DVARWAY56>",
+       },
+       {
+               .name = "xtmpu",
+               .handler = xtensa_cmd_xtmpu,
+               .mode = COMMAND_CONFIG,
+               .help = "Configure Xtensa MPU option",
+               .usage = "<num FG seg> <min seg size> <lockable> <executeonly>",
+       },
+       {
+               .name = "xtreg",
+               .handler = xtensa_cmd_xtreg,
+               .mode = COMMAND_CONFIG,
+               .help = "Configure Xtensa register",
+               .usage = "<regname> <regnum>",
+       },
+       {
+               .name = "xtregs",
+               .handler = xtensa_cmd_xtreg,
+               .mode = COMMAND_CONFIG,
+               .help = "Configure number of Xtensa registers",
+               .usage = "<numregs>",
+       },
+       {
+               .name = "xtregfmt",
+               .handler = xtensa_cmd_xtregfmt,
+               .mode = COMMAND_CONFIG,
+               .help = "Configure format of Xtensa register map",
+               .usage = "<contiguous|sparse> [numgregs]",
+       },
        {
                .name = "set_permissive",
                .handler = xtensa_cmd_permissive_mode,
                .mode = COMMAND_ANY,
-               .help = "When set to 1, enable Xtensa permissive mode (less client-side checks)",
+               .help = "When set to 1, enable Xtensa permissive mode (fewer client-side checks)",
                .usage = "[0|1]",
        },
        {
@@ -2673,8 +3941,7 @@ const struct command_registration xtensa_command_handlers[] = {
                .handler = xtensa_cmd_smpbreak,
                .mode = COMMAND_ANY,
                .help = "Set the way the CPU chains OCD breaks",
-               .usage =
-                       "[none|breakinout|runstall] | [BreakIn] [BreakOut] [RunStallIn] [DebugModeOut]",
+               .usage = "[none|breakinout|runstall] | [BreakIn] [BreakOut] [RunStallIn] [DebugModeOut]",
        },
        {
                .name = "perfmon_enable",
@@ -2687,8 +3954,7 @@ const struct command_registration xtensa_command_handlers[] = {
                .name = "perfmon_dump",
                .handler = xtensa_cmd_perfmon_dump,
                .mode = COMMAND_EXEC,
-               .help =
-                       "Dump performance counter value. If no argument specified, dumps all counters.",
+               .help = "Dump performance counter value. If no argument specified, dumps all counters.",
                .usage = "[counter_id]",
        },
        {
@@ -2713,5 +3979,23 @@ const struct command_registration xtensa_command_handlers[] = {
                .help = "Tracing: Dump trace memory to a files. One file per core.",
                .usage = "<outfile>",
        },
+       {
+               .name = "exe",
+               .handler = xtensa_cmd_exe,
+               .mode = COMMAND_ANY,
+               .help = "Xtensa stub execution",
+               .usage = "<ascii-encoded hexadecimal instruction bytes>",
+       },
+       COMMAND_REGISTRATION_DONE
+};
+
+const struct command_registration xtensa_command_handlers[] = {
+       {
+               .name = "xtensa",
+               .mode = COMMAND_ANY,
+               .help = "Xtensa command group",
+               .usage = "",
+               .chain = xtensa_any_command_handlers,
+       },
        COMMAND_REGISTRATION_DONE
 };