target/cortex_m: minor refactoring in cortex_m_store_core_reg_u32()
[fw/openocd] / src / target / cortex_m.c
index e52332dd620dfdfcc32185dc561a4f96dd3805bf..7125e9e8309f41873a81dbe8b2a05fecbfa6a56e 100644 (file)
 #include "cortex_m.h"
 #include "target_request.h"
 #include "target_type.h"
+#include "arm_adi_v5.h"
 #include "arm_disassembler.h"
 #include "register.h"
 #include "arm_opcodes.h"
 #include "arm_semihosting.h"
 #include <helper/time_support.h>
+#include <rtt/rtt.h>
 
 /* NOTE:  most of this should work fine for the Cortex-M1 and
  * Cortex-M0 cores too, although they're ARMv6-M not ARMv7-M.
  * any longer.
  */
 
+/* Timeout for register r/w */
+#define DHCSR_S_REGRDY_TIMEOUT (500)
+
+/* Supported Cortex-M Cores */
+static const struct cortex_m_part_info cortex_m_parts[] = {
+       {
+               .partno = CORTEX_M0_PARTNO,
+               .name = "Cortex-M0",
+               .arch = ARM_ARCH_V6M,
+       },
+       {
+               .partno = CORTEX_M0P_PARTNO,
+               .name = "Cortex-M0+",
+               .arch = ARM_ARCH_V6M,
+       },
+       {
+               .partno = CORTEX_M1_PARTNO,
+               .name = "Cortex-M1",
+               .arch = ARM_ARCH_V6M,
+       },
+       {
+               .partno = CORTEX_M3_PARTNO,
+               .name = "Cortex-M3",
+               .arch = ARM_ARCH_V7M,
+               .flags = CORTEX_M_F_TAR_AUTOINCR_BLOCK_4K,
+       },
+       {
+               .partno = CORTEX_M4_PARTNO,
+               .name = "Cortex-M4",
+               .arch = ARM_ARCH_V7M,
+               .flags = CORTEX_M_F_HAS_FPV4 | CORTEX_M_F_TAR_AUTOINCR_BLOCK_4K,
+       },
+       {
+               .partno = CORTEX_M7_PARTNO,
+               .name = "Cortex-M7",
+               .arch = ARM_ARCH_V7M,
+               .flags = CORTEX_M_F_HAS_FPV5,
+       },
+       {
+               .partno = CORTEX_M23_PARTNO,
+               .name = "Cortex-M23",
+               .arch = ARM_ARCH_V8M,
+       },
+       {
+               .partno = CORTEX_M33_PARTNO,
+               .name = "Cortex-M33",
+               .arch = ARM_ARCH_V8M,
+               .flags = CORTEX_M_F_HAS_FPV5,
+       },
+       {
+               .partno = CORTEX_M35P_PARTNO,
+               .name = "Cortex-M35P",
+               .arch = ARM_ARCH_V8M,
+               .flags = CORTEX_M_F_HAS_FPV5,
+       },
+       {
+               .partno = CORTEX_M55_PARTNO,
+               .name = "Cortex-M55",
+               .arch = ARM_ARCH_V8M,
+               .flags = CORTEX_M_F_HAS_FPV5,
+       },
+};
+
 /* forward declarations */
 static int cortex_m_store_core_reg_u32(struct target *target,
                uint32_t num, uint32_t value);
 static void cortex_m_dwt_free(struct target *target);
 
-static int cortexm_dap_read_coreregister_u32(struct target *target,
-       uint32_t *value, int regnum)
+/** DCB DHCSR register contains S_RETIRE_ST and S_RESET_ST bits cleared
+ *  on a read. Call this helper function each time DHCSR is read
+ *  to preserve S_RESET_ST state in case of a reset event was detected.
+ */
+static inline void cortex_m_cumulate_dhcsr_sticky(struct cortex_m_common *cortex_m,
+               uint32_t dhcsr)
+{
+       cortex_m->dcb_dhcsr_cumulated_sticky |= dhcsr;
+}
+
+/** Read DCB DHCSR register to cortex_m->dcb_dhcsr and cumulate
+ * sticky bits in cortex_m->dcb_dhcsr_cumulated_sticky
+ */
+static int cortex_m_read_dhcsr_atomic_sticky(struct target *target)
+{
+       struct cortex_m_common *cortex_m = target_to_cm(target);
+       struct armv7m_common *armv7m = target_to_armv7m(target);
+
+       int retval = mem_ap_read_atomic_u32(armv7m->debug_ap, DCB_DHCSR,
+                               &cortex_m->dcb_dhcsr);
+       if (retval != ERROR_OK)
+               return retval;
+
+       cortex_m_cumulate_dhcsr_sticky(cortex_m, cortex_m->dcb_dhcsr);
+       return ERROR_OK;
+}
+
+static int cortex_m_load_core_reg_u32(struct target *target,
+               uint32_t regsel, uint32_t *value)
 {
+       struct cortex_m_common *cortex_m = target_to_cm(target);
        struct armv7m_common *armv7m = target_to_armv7m(target);
        int retval;
-       uint32_t dcrdr;
+       uint32_t dcrdr, tmp_value;
+       int64_t then;
 
        /* because the DCB_DCRDR is used for the emulated dcc channel
         * we have to save/restore the DCB_DCRDR when used */
@@ -71,13 +165,33 @@ static int cortexm_dap_read_coreregister_u32(struct target *target,
                        return retval;
        }
 
-       retval = mem_ap_write_u32(armv7m->debug_ap, DCB_DCRSR, regnum);
+       retval = mem_ap_write_u32(armv7m->debug_ap, DCB_DCRSR, regsel);
        if (retval != ERROR_OK)
                return retval;
 
-       retval = mem_ap_read_atomic_u32(armv7m->debug_ap, DCB_DCRDR, value);
-       if (retval != ERROR_OK)
-               return retval;
+       /* check if value from register is ready and pre-read it */
+       then = timeval_ms();
+       while (1) {
+               retval = mem_ap_read_u32(armv7m->debug_ap, DCB_DHCSR,
+                                                                &cortex_m->dcb_dhcsr);
+               if (retval != ERROR_OK)
+                       return retval;
+               retval = mem_ap_read_atomic_u32(armv7m->debug_ap, DCB_DCRDR,
+                                                                               &tmp_value);
+               if (retval != ERROR_OK)
+                       return retval;
+               cortex_m_cumulate_dhcsr_sticky(cortex_m, cortex_m->dcb_dhcsr);
+               if (cortex_m->dcb_dhcsr & S_REGRDY)
+                       break;
+               cortex_m->slow_register_read = true; /* Polling (still) needed. */
+               if (timeval_ms() > then + DHCSR_S_REGRDY_TIMEOUT) {
+                       LOG_ERROR("Timeout waiting for DCRDR transfer ready");
+                       return ERROR_TIMEOUT_REACHED;
+               }
+               keep_alive();
+       }
+
+       *value = tmp_value;
 
        if (target->dbg_msg_enabled) {
                /* restore DCB_DCRDR - this needs to be in a separate
@@ -89,12 +203,180 @@ static int cortexm_dap_read_coreregister_u32(struct target *target,
        return retval;
 }
 
-static int cortexm_dap_write_coreregister_u32(struct target *target,
-       uint32_t value, int regnum)
+static int cortex_m_slow_read_all_regs(struct target *target)
+{
+       struct cortex_m_common *cortex_m = target_to_cm(target);
+       struct armv7m_common *armv7m = target_to_armv7m(target);
+       const unsigned int num_regs = armv7m->arm.core_cache->num_regs;
+
+       /* Opportunistically restore fast read, it'll revert to slow
+        * if any register needed polling in cortex_m_load_core_reg_u32(). */
+       cortex_m->slow_register_read = false;
+
+       for (unsigned int reg_id = 0; reg_id < num_regs; reg_id++) {
+               struct reg *r = &armv7m->arm.core_cache->reg_list[reg_id];
+               if (r->exist) {
+                       int retval = armv7m->arm.read_core_reg(target, r, reg_id, ARM_MODE_ANY);
+                       if (retval != ERROR_OK)
+                               return retval;
+               }
+       }
+
+       if (!cortex_m->slow_register_read)
+               LOG_DEBUG("Switching back to fast register reads");
+
+       return ERROR_OK;
+}
+
+static int cortex_m_queue_reg_read(struct target *target, uint32_t regsel,
+               uint32_t *reg_value, uint32_t *dhcsr)
+{
+       struct armv7m_common *armv7m = target_to_armv7m(target);
+       int retval;
+
+       retval = mem_ap_write_u32(armv7m->debug_ap, DCB_DCRSR, regsel);
+       if (retval != ERROR_OK)
+               return retval;
+
+       retval = mem_ap_read_u32(armv7m->debug_ap, DCB_DHCSR, dhcsr);
+       if (retval != ERROR_OK)
+               return retval;
+
+       return mem_ap_read_u32(armv7m->debug_ap, DCB_DCRDR, reg_value);
+}
+
+static int cortex_m_fast_read_all_regs(struct target *target)
+{
+       struct cortex_m_common *cortex_m = target_to_cm(target);
+       struct armv7m_common *armv7m = target_to_armv7m(target);
+       int retval;
+       uint32_t dcrdr;
+
+       /* because the DCB_DCRDR is used for the emulated dcc channel
+        * we have to save/restore the DCB_DCRDR when used */
+       if (target->dbg_msg_enabled) {
+               retval = mem_ap_read_u32(armv7m->debug_ap, DCB_DCRDR, &dcrdr);
+               if (retval != ERROR_OK)
+                       return retval;
+       }
+
+       const unsigned int num_regs = armv7m->arm.core_cache->num_regs;
+       const unsigned int n_r32 = ARMV7M_LAST_REG - ARMV7M_CORE_FIRST_REG + 1
+                                                          + ARMV7M_FPU_LAST_REG - ARMV7M_FPU_FIRST_REG + 1;
+       /* we need one 32-bit word for each register except FP D0..D15, which
+        * need two words */
+       uint32_t r_vals[n_r32];
+       uint32_t dhcsr[n_r32];
+
+       unsigned int wi = 0; /* write index to r_vals and dhcsr arrays */
+       unsigned int reg_id; /* register index in the reg_list, ARMV7M_R0... */
+       for (reg_id = 0; reg_id < num_regs; reg_id++) {
+               struct reg *r = &armv7m->arm.core_cache->reg_list[reg_id];
+               if (!r->exist)
+                       continue;       /* skip non existent registers */
+
+               if (r->size <= 8) {
+                       /* Any 8-bit or shorter register is unpacked from a 32-bit
+                        * container register. Skip it now. */
+                       continue;
+               }
+
+               uint32_t regsel = armv7m_map_id_to_regsel(reg_id);
+               retval = cortex_m_queue_reg_read(target, regsel, &r_vals[wi],
+                                                                                &dhcsr[wi]);
+               if (retval != ERROR_OK)
+                       return retval;
+               wi++;
+
+               assert(r->size == 32 || r->size == 64);
+               if (r->size == 32)
+                       continue;       /* done with 32-bit register */
+
+               assert(reg_id >= ARMV7M_FPU_FIRST_REG && reg_id <= ARMV7M_FPU_LAST_REG);
+               /* the odd part of FP register (S1, S3...) */
+               retval = cortex_m_queue_reg_read(target, regsel + 1, &r_vals[wi],
+                                                                                        &dhcsr[wi]);
+               if (retval != ERROR_OK)
+                       return retval;
+               wi++;
+       }
+
+       assert(wi <= n_r32);
+
+       retval = dap_run(armv7m->debug_ap->dap);
+       if (retval != ERROR_OK)
+               return retval;
+
+       if (target->dbg_msg_enabled) {
+               /* restore DCB_DCRDR - this needs to be in a separate
+                * transaction otherwise the emulated DCC channel breaks */
+               retval = mem_ap_write_atomic_u32(armv7m->debug_ap, DCB_DCRDR, dcrdr);
+               if (retval != ERROR_OK)
+                       return retval;
+       }
+
+       bool not_ready = false;
+       for (unsigned int i = 0; i < wi; i++) {
+               if ((dhcsr[i] & S_REGRDY) == 0) {
+                       not_ready = true;
+                       LOG_DEBUG("Register %u was not ready during fast read", i);
+               }
+               cortex_m_cumulate_dhcsr_sticky(cortex_m, dhcsr[i]);
+       }
+
+       if (not_ready) {
+               /* Any register was not ready,
+                * fall back to slow read with S_REGRDY polling */
+               return ERROR_TIMEOUT_REACHED;
+       }
+
+       LOG_DEBUG("read %u 32-bit registers", wi);
+
+       unsigned int ri = 0; /* read index from r_vals array */
+       for (reg_id = 0; reg_id < num_regs; reg_id++) {
+               struct reg *r = &armv7m->arm.core_cache->reg_list[reg_id];
+               if (!r->exist)
+                       continue;       /* skip non existent registers */
+
+               r->dirty = false;
+
+               unsigned int reg32_id;
+               uint32_t offset;
+               if (armv7m_map_reg_packing(reg_id, &reg32_id, &offset)) {
+                       /* Unpack a partial register from 32-bit container register */
+                       struct reg *r32 = &armv7m->arm.core_cache->reg_list[reg32_id];
+
+                       /* The container register ought to precede all regs unpacked
+                        * from it in the reg_list. So the value should be ready
+                        * to unpack */
+                       assert(r32->valid);
+                       buf_cpy(r32->value + offset, r->value, r->size);
+
+               } else {
+                       assert(r->size == 32 || r->size == 64);
+                       buf_set_u32(r->value, 0, 32, r_vals[ri++]);
+
+                       if (r->size == 64) {
+                               assert(reg_id >= ARMV7M_FPU_FIRST_REG && reg_id <= ARMV7M_FPU_LAST_REG);
+                               /* the odd part of FP register (S1, S3...) */
+                               buf_set_u32(r->value + 4, 0, 32, r_vals[ri++]);
+                       }
+               }
+               r->valid = true;
+       }
+       assert(ri == wi);
+
+       return retval;
+}
+
+static int cortex_m_store_core_reg_u32(struct target *target,
+               uint32_t regsel, uint32_t value)
 {
+       struct cortex_m_common *cortex_m = target_to_cm(target);
        struct armv7m_common *armv7m = target_to_armv7m(target);
        int retval;
        uint32_t dcrdr;
+       int64_t then;
 
        /* because the DCB_DCRDR is used for the emulated dcc channel
         * we have to save/restore the DCB_DCRDR when used */
@@ -108,10 +390,25 @@ static int cortexm_dap_write_coreregister_u32(struct target *target,
        if (retval != ERROR_OK)
                return retval;
 
-       retval = mem_ap_write_atomic_u32(armv7m->debug_ap, DCB_DCRSR, regnum | DCRSR_WnR);
+       retval = mem_ap_write_u32(armv7m->debug_ap, DCB_DCRSR, regsel | DCRSR_WNR);
        if (retval != ERROR_OK)
                return retval;
 
+       /* check if value is written into register */
+       then = timeval_ms();
+       while (1) {
+               retval = cortex_m_read_dhcsr_atomic_sticky(target);
+               if (retval != ERROR_OK)
+                       return retval;
+               if (cortex_m->dcb_dhcsr & S_REGRDY)
+                       break;
+               if (timeval_ms() > then + DHCSR_S_REGRDY_TIMEOUT) {
+                       LOG_ERROR("Timeout waiting for DCRDR transfer ready");
+                       return ERROR_TIMEOUT_REACHED;
+               }
+               keep_alive();
+       }
+
        if (target->dbg_msg_enabled) {
                /* restore DCB_DCRDR - this needs to be in a separate
                 * transaction otherwise the emulated DCC channel breaks */
@@ -239,7 +536,6 @@ static int cortex_m_clear_halt(struct target *target)
 static int cortex_m_single_step_core(struct target *target)
 {
        struct cortex_m_common *cortex_m = target_to_cm(target);
-       struct armv7m_common *armv7m = &cortex_m->armv7m;
        int retval;
 
        /* Mask interrupts before clearing halt, if not done already.  This avoids
@@ -247,13 +543,11 @@ static int cortex_m_single_step_core(struct target *target)
         * HALT can put the core into an unknown state.
         */
        if (!(cortex_m->dcb_dhcsr & C_MASKINTS)) {
-               retval = mem_ap_write_atomic_u32(armv7m->debug_ap, DCB_DHCSR,
-                               DBGKEY | C_MASKINTS | C_HALT | C_DEBUGEN);
+               retval = cortex_m_write_debug_halt_mask(target, C_MASKINTS, 0);
                if (retval != ERROR_OK)
                        return retval;
        }
-       retval = mem_ap_write_atomic_u32(armv7m->debug_ap, DCB_DHCSR,
-                       DBGKEY | C_MASKINTS | C_STEP | C_DEBUGEN);
+       retval = cortex_m_write_debug_halt_mask(target, C_STEP, C_HALT);
        if (retval != ERROR_OK)
                return retval;
        LOG_DEBUG(" ");
@@ -284,7 +578,6 @@ static int cortex_m_enable_fpb(struct target *target)
 
 static int cortex_m_endreset_event(struct target *target)
 {
-       int i;
        int retval;
        uint32_t dcb_demcr;
        struct cortex_m_common *cortex_m = target_to_cm(target);
@@ -304,11 +597,12 @@ static int cortex_m_endreset_event(struct target *target)
        if (retval != ERROR_OK)
                return retval;
 
-       /* Enable debug requests */
-       retval = mem_ap_read_atomic_u32(armv7m->debug_ap, DCB_DHCSR, &cortex_m->dcb_dhcsr);
+       retval = cortex_m_read_dhcsr_atomic_sticky(target);
        if (retval != ERROR_OK)
                return retval;
+
        if (!(cortex_m->dcb_dhcsr & C_DEBUGEN)) {
+               /* Enable debug requests */
                retval = cortex_m_write_debug_halt_mask(target, 0, C_HALT | C_STEP | C_MASKINTS);
                if (retval != ERROR_OK)
                        return retval;
@@ -342,14 +636,14 @@ static int cortex_m_endreset_event(struct target *target)
        cortex_m->fpb_enabled = true;
 
        /* Restore FPB registers */
-       for (i = 0; i < cortex_m->fp_num_code + cortex_m->fp_num_lit; i++) {
+       for (unsigned int i = 0; i < cortex_m->fp_num_code + cortex_m->fp_num_lit; i++) {
                retval = target_write_u32(target, fp_list[i].fpcr_address, fp_list[i].fpcr_value);
                if (retval != ERROR_OK)
                        return retval;
        }
 
        /* Restore DWT registers */
-       for (i = 0; i < cortex_m->dwt_num_comp; i++) {
+       for (unsigned int i = 0; i < cortex_m->dwt_num_comp; i++) {
                retval = target_write_u32(target, dwt_list[i].dwt_comparator_address + 0,
                                dwt_list[i].comp);
                if (retval != ERROR_OK)
@@ -370,7 +664,9 @@ static int cortex_m_endreset_event(struct target *target)
        register_cache_invalidate(armv7m->arm.core_cache);
 
        /* make sure we have latest dhcsr flags */
-       retval = mem_ap_read_atomic_u32(armv7m->debug_ap, DCB_DHCSR, &cortex_m->dcb_dhcsr);
+       retval = cortex_m_read_dhcsr_atomic_sticky(target);
+       if (retval != ERROR_OK)
+               return retval;
 
        return retval;
 }
@@ -479,7 +775,6 @@ static int cortex_m_examine_exception_reason(struct target *target)
 
 static int cortex_m_debug_entry(struct target *target)
 {
-       int i;
        uint32_t xPSR;
        int retval;
        struct cortex_m_common *cortex_m = target_to_cm(target);
@@ -494,7 +789,8 @@ static int cortex_m_debug_entry(struct target *target)
        cortex_m_set_maskints_for_halt(target);
 
        cortex_m_clear_halt(target);
-       retval = mem_ap_read_atomic_u32(armv7m->debug_ap, DCB_DHCSR, &cortex_m->dcb_dhcsr);
+
+       retval = cortex_m_read_dhcsr_atomic_sticky(target);
        if (retval != ERROR_OK)
                return retval;
 
@@ -504,7 +800,7 @@ static int cortex_m_debug_entry(struct target *target)
 
        /* examine PE security state */
        bool secure_state = false;
-       if (armv7m->arm.is_armv8m) {
+       if (armv7m->arm.arch == ARM_ARCH_V8M) {
                uint32_t dscsr;
 
                retval = mem_ap_read_u32(armv7m->debug_ap, DCB_DSCSR, &dscsr);
@@ -514,25 +810,24 @@ static int cortex_m_debug_entry(struct target *target)
                secure_state = (dscsr & DSCSR_CDS) == DSCSR_CDS;
        }
 
-       /* Examine target state and mode
-        * First load register accessible through core debug port */
-       int num_regs = arm->core_cache->num_regs;
-
-       for (i = 0; i < num_regs; i++) {
-               r = &armv7m->arm.core_cache->reg_list[i];
-               if (!r->valid)
-                       arm->read_core_reg(target, r, i, ARM_MODE_ANY);
+       /* Load all registers to arm.core_cache */
+       if (!cortex_m->slow_register_read) {
+               retval = cortex_m_fast_read_all_regs(target);
+               if (retval == ERROR_TIMEOUT_REACHED) {
+                       cortex_m->slow_register_read = true;
+                       LOG_DEBUG("Switched to slow register read");
+               }
        }
 
+       if (cortex_m->slow_register_read)
+               retval = cortex_m_slow_read_all_regs(target);
+
+       if (retval != ERROR_OK)
+               return retval;
+
        r = arm->cpsr;
        xPSR = buf_get_u32(r->value, 0, 32);
 
-       /* For IT instructions xPSR must be reloaded on resume and clear on debug exec */
-       if (xPSR & 0xf00) {
-               r->dirty = r->valid;
-               cortex_m_store_core_reg_u32(target, 16, xPSR & ~0xff);
-       }
-
        /* Are we in an exception handler */
        if (xPSR & 0x1FF) {
                armv7m->exception_number = (xPSR & 0x1FF);
@@ -541,7 +836,7 @@ static int cortex_m_debug_entry(struct target *target)
                arm->map = armv7m_msp_reg_map;
        } else {
                unsigned control = buf_get_u32(arm->core_cache
-                               ->reg_list[ARMV7M_CONTROL].value, 0, 2);
+                               ->reg_list[ARMV7M_CONTROL].value, 0, 3);
 
                /* is this thread privileged? */
                arm->core_mode = control & 1
@@ -584,7 +879,7 @@ static int cortex_m_poll(struct target *target)
        struct armv7m_common *armv7m = &cortex_m->armv7m;
 
        /* Read from Debug Halting Control and Status Register */
-       retval = mem_ap_read_atomic_u32(armv7m->debug_ap, DCB_DHCSR, &cortex_m->dcb_dhcsr);
+       retval = cortex_m_read_dhcsr_atomic_sticky(target);
        if (retval != ERROR_OK) {
                target->state = TARGET_UNKNOWN;
                return retval;
@@ -605,12 +900,13 @@ static int cortex_m_poll(struct target *target)
                detected_failure = ERROR_FAIL;
 
                /* refresh status bits */
-               retval = mem_ap_read_atomic_u32(armv7m->debug_ap, DCB_DHCSR, &cortex_m->dcb_dhcsr);
+               retval = cortex_m_read_dhcsr_atomic_sticky(target);
                if (retval != ERROR_OK)
                        return retval;
        }
 
-       if (cortex_m->dcb_dhcsr & S_RESET_ST) {
+       if (cortex_m->dcb_dhcsr_cumulated_sticky & S_RESET_ST) {
+               cortex_m->dcb_dhcsr_cumulated_sticky &= ~S_RESET_ST;
                if (target->state != TARGET_RESET) {
                        target->state = TARGET_RESET;
                        LOG_INFO("%s: external reset detected", target_name(target));
@@ -656,13 +952,14 @@ static int cortex_m_poll(struct target *target)
                }
        }
 
-       /* REVISIT when S_SLEEP is set, it's in a Sleep or DeepSleep state.
-        * How best to model low power modes?
-        */
-
        if (target->state == TARGET_UNKNOWN) {
-               /* check if processor is retiring instructions */
-               if (cortex_m->dcb_dhcsr & S_RETIRE_ST) {
+               /* Check if processor is retiring instructions or sleeping.
+                * Unlike S_RESET_ST here we test if the target *is* running now,
+                * not if it has been running (possibly in the past). Instructions are
+                * typically processed much faster than OpenOCD polls DHCSR so S_RETIRE_ST
+                * is read always 1. That's the reason not to use dcb_dhcsr_cumulated_sticky.
+                */
+               if (cortex_m->dcb_dhcsr & S_RETIRE_ST || cortex_m->dcb_dhcsr & S_SLEEP) {
                        target->state = TARGET_RUNNING;
                        retval = ERROR_OK;
                }
@@ -728,7 +1025,6 @@ static int cortex_m_soft_reset_halt(struct target *target)
 {
        struct cortex_m_common *cortex_m = target_to_cm(target);
        struct armv7m_common *armv7m = &cortex_m->armv7m;
-       uint32_t dcb_dhcsr = 0;
        int retval, timeout = 0;
 
        /* on single cortex_m MCU soft_reset_halt should be avoided as same functionality
@@ -737,6 +1033,11 @@ static int cortex_m_soft_reset_halt(struct target *target)
         * core, not the peripherals */
        LOG_DEBUG("soft_reset_halt is discouraged, please use 'reset halt' instead.");
 
+       if (!cortex_m->vectreset_supported) {
+               LOG_ERROR("VECTRESET is not supported on this Cortex-M core");
+               return ERROR_FAIL;
+       }
+
        /* Set C_DEBUGEN */
        retval = cortex_m_write_debug_halt_mask(target, 0, C_STEP | C_MASKINTS);
        if (retval != ERROR_OK)
@@ -759,25 +1060,23 @@ static int cortex_m_soft_reset_halt(struct target *target)
        register_cache_invalidate(cortex_m->armv7m.arm.core_cache);
 
        while (timeout < 100) {
-               retval = mem_ap_read_atomic_u32(armv7m->debug_ap, DCB_DHCSR, &dcb_dhcsr);
+               retval = cortex_m_read_dhcsr_atomic_sticky(target);
                if (retval == ERROR_OK) {
                        retval = mem_ap_read_atomic_u32(armv7m->debug_ap, NVIC_DFSR,
                                        &cortex_m->nvic_dfsr);
                        if (retval != ERROR_OK)
                                return retval;
-                       if ((dcb_dhcsr & S_HALT)
+                       if ((cortex_m->dcb_dhcsr & S_HALT)
                                && (cortex_m->nvic_dfsr & DFSR_VCATCH)) {
-                               LOG_DEBUG("system reset-halted, DHCSR 0x%08x, "
-                                       "DFSR 0x%08x",
-                                       (unsigned) dcb_dhcsr,
-                                       (unsigned) cortex_m->nvic_dfsr);
+                               LOG_DEBUG("system reset-halted, DHCSR 0x%08" PRIx32 ", DFSR 0x%08" PRIx32,
+                                       cortex_m->dcb_dhcsr, cortex_m->nvic_dfsr);
                                cortex_m_poll(target);
                                /* FIXME restore user's vector catch config */
                                return ERROR_OK;
                        } else
                                LOG_DEBUG("waiting for system reset-halt, "
-                                       "DHCSR 0x%08x, %d ms",
-                                       (unsigned) dcb_dhcsr, timeout);
+                                       "DHCSR 0x%08" PRIx32 ", %d ms",
+                                       cortex_m->dcb_dhcsr, timeout);
                }
                timeout++;
                alive_sleep(1);
@@ -827,15 +1126,19 @@ static int cortex_m_resume(struct target *target, int current,
                 * in parallel with disabled interrupts can cause local faults
                 * to not be taken.
                 *
-                * REVISIT this clearly breaks non-debug execution, since the
-                * PRIMASK register state isn't saved/restored...  workaround
-                * by never resuming app code after debug execution.
+                * This breaks non-debug (application) execution if not
+                * called from armv7m_start_algorithm() which saves registers.
                 */
                buf_set_u32(r->value, 0, 1, 1);
                r->dirty = true;
                r->valid = true;
 
-               /* Make sure we are in Thumb mode */
+               /* Make sure we are in Thumb mode, set xPSR.T bit */
+               /* armv7m_start_algorithm() initializes entire xPSR register.
+                * This duplicity handles the case when cortex_m_resume()
+                * is used with the debug_execution flag directly,
+                * not called through armv7m_start_algorithm().
+                */
                r = armv7m->arm.cpsr;
                buf_set_u32(r->value, 24, 1, 1);
                r->dirty = true;
@@ -916,8 +1219,11 @@ static int cortex_m_step(struct target *target, int current,
        }
 
        /* current = 1: continue on current pc, otherwise continue at <address> */
-       if (!current)
+       if (!current) {
                buf_set_u32(pc->value, 0, 32, address);
+               pc->dirty = true;
+               pc->valid = true;
+       }
 
        uint32_t pc_value = buf_get_u32(pc->value, 0, 32);
 
@@ -1019,9 +1325,7 @@ static int cortex_m_step(struct target *target, int current,
 
                                        /* Wait for pending handlers to complete or timeout */
                                        do {
-                                               retval = mem_ap_read_atomic_u32(armv7m->debug_ap,
-                                                               DCB_DHCSR,
-                                                               &cortex_m->dcb_dhcsr);
+                                               retval = cortex_m_read_dhcsr_atomic_sticky(target);
                                                if (retval != ERROR_OK) {
                                                        target->state = TARGET_UNKNOWN;
                                                        return retval;
@@ -1056,7 +1360,7 @@ static int cortex_m_step(struct target *target, int current,
                }
        }
 
-       retval = mem_ap_read_atomic_u32(armv7m->debug_ap, DCB_DHCSR, &cortex_m->dcb_dhcsr);
+       retval = cortex_m_read_dhcsr_atomic_sticky(target);
        if (retval != ERROR_OK)
                return retval;
 
@@ -1134,8 +1438,8 @@ static int cortex_m_assert_reset(struct target *target)
        }
 
        /* Enable debug requests */
-       int retval;
-       retval = mem_ap_read_atomic_u32(armv7m->debug_ap, DCB_DHCSR, &cortex_m->dcb_dhcsr);
+       int retval = cortex_m_read_dhcsr_atomic_sticky(target);
+
        /* Store important errors instead of failing and proceed to reset assert */
 
        if (retval != ERROR_OK || !(cortex_m->dcb_dhcsr & C_DEBUGEN))
@@ -1181,7 +1485,7 @@ static int cortex_m_assert_reset(struct target *target)
                retval = ERROR_OK;
        } else {
                /* Use a standard Cortex-M3 software reset mechanism.
-                * We default to using VECRESET as it is supported on all current cores
+                * We default to using VECTRESET as it is supported on all current cores
                 * (except Cortex-M0, M0+ and M1 which support SYSRESETREQ only!)
                 * This has the disadvantage of not resetting the peripherals, so a
                 * reset-init event handler is needed to perform any peripheral resets.
@@ -1208,11 +1512,13 @@ static int cortex_m_assert_reset(struct target *target)
                if (retval3 != ERROR_OK)
                        LOG_DEBUG("Ignoring AP write error right after reset");
 
-               retval3 = dap_dp_init(armv7m->debug_ap->dap);
-               if (retval3 != ERROR_OK)
+               retval3 = dap_dp_init_or_reconnect(armv7m->debug_ap->dap);
+               if (retval3 != ERROR_OK) {
                        LOG_ERROR("DP initialisation failed");
-
-               else {
+                       /* The error return value must not be propagated in this case.
+                        * SYSRESETREQ or VECTRESET have been possibly triggered
+                        * so reset processing should continue */
+               } else {
                        /* I do not know why this is necessary, but it
                         * fixes strange effects (step/resume cause NMI
                         * after reset) on LM3S6918 -- Michael Schwingen
@@ -1255,7 +1561,8 @@ static int cortex_m_deassert_reset(struct target *target)
        if ((jtag_reset_config & RESET_HAS_SRST) &&
            !(jtag_reset_config & RESET_SRST_NO_GATING) &&
                target_was_examined(target)) {
-               int retval = dap_dp_init(armv7m->debug_ap->dap);
+
+               int retval = dap_dp_init_or_reconnect(armv7m->debug_ap->dap);
                if (retval != ERROR_OK) {
                        LOG_ERROR("DP initialisation failed");
                        return retval;
@@ -1268,7 +1575,7 @@ static int cortex_m_deassert_reset(struct target *target)
 int cortex_m_set_breakpoint(struct target *target, struct breakpoint *breakpoint)
 {
        int retval;
-       int fp_num = 0;
+       unsigned int fp_num = 0;
        struct cortex_m_common *cortex_m = target_to_cm(target);
        struct cortex_m_fp_comparator *comparator_list = cortex_m->fp_comparator_list;
 
@@ -1355,7 +1662,7 @@ int cortex_m_unset_breakpoint(struct target *target, struct breakpoint *breakpoi
        struct cortex_m_common *cortex_m = target_to_cm(target);
        struct cortex_m_fp_comparator *comparator_list = cortex_m->fp_comparator_list;
 
-       if (!breakpoint->set) {
+       if (breakpoint->set <= 0) {
                LOG_WARNING("breakpoint not set");
                return ERROR_OK;
        }
@@ -1368,8 +1675,8 @@ int cortex_m_unset_breakpoint(struct target *target, struct breakpoint *breakpoi
                breakpoint->set);
 
        if (breakpoint->type == BKPT_HARD) {
-               int fp_num = breakpoint->set - 1;
-               if ((fp_num < 0) || (fp_num >= cortex_m->fp_num_code)) {
+               unsigned int fp_num = breakpoint->set - 1;
+               if (fp_num >= cortex_m->fp_num_code) {
                        LOG_DEBUG("Invalid FP Comparator number in breakpoint");
                        return ERROR_OK;
                }
@@ -1413,9 +1720,9 @@ int cortex_m_remove_breakpoint(struct target *target, struct breakpoint *breakpo
        return cortex_m_unset_breakpoint(target, breakpoint);
 }
 
-int cortex_m_set_watchpoint(struct target *target, struct watchpoint *watchpoint)
+static int cortex_m_set_watchpoint(struct target *target, struct watchpoint *watchpoint)
 {
-       int dwt_num = 0;
+       unsigned int dwt_num = 0;
        struct cortex_m_common *cortex_m = target_to_cm(target);
 
        /* REVISIT Don't fully trust these "not used" records ... users
@@ -1496,25 +1803,24 @@ int cortex_m_set_watchpoint(struct target *target, struct watchpoint *watchpoint
        return ERROR_OK;
 }
 
-int cortex_m_unset_watchpoint(struct target *target, struct watchpoint *watchpoint)
+static int cortex_m_unset_watchpoint(struct target *target, struct watchpoint *watchpoint)
 {
        struct cortex_m_common *cortex_m = target_to_cm(target);
        struct cortex_m_dwt_comparator *comparator;
-       int dwt_num;
 
-       if (!watchpoint->set) {
+       if (watchpoint->set <= 0) {
                LOG_WARNING("watchpoint (wpid: %d) not set",
                        watchpoint->unique_id);
                return ERROR_OK;
        }
 
-       dwt_num = watchpoint->set - 1;
+       unsigned int dwt_num = watchpoint->set - 1;
 
        LOG_DEBUG("Watchpoint (ID %d) DWT%d address: 0x%08x clear",
                watchpoint->unique_id, dwt_num,
                (unsigned) watchpoint->address);
 
-       if ((dwt_num < 0) || (dwt_num >= cortex_m->dwt_num_comp)) {
+       if (dwt_num >= cortex_m->dwt_num_comp) {
                LOG_DEBUG("Invalid DWT Comparator number in watchpoint");
                return ERROR_OK;
        }
@@ -1598,186 +1904,45 @@ int cortex_m_remove_watchpoint(struct target *target, struct watchpoint *watchpo
        return ERROR_OK;
 }
 
-void cortex_m_enable_watchpoints(struct target *target)
+int cortex_m_hit_watchpoint(struct target *target, struct watchpoint **hit_watchpoint)
 {
-       struct watchpoint *watchpoint = target->watchpoints;
-
-       /* set any pending watchpoints */
-       while (watchpoint) {
-               if (!watchpoint->set)
-                       cortex_m_set_watchpoint(target, watchpoint);
-               watchpoint = watchpoint->next;
-       }
-}
-
-static int cortex_m_load_core_reg_u32(struct target *target,
-               uint32_t num, uint32_t *value)
-{
-       int retval;
-
-       /* NOTE:  we "know" here that the register identifiers used
-        * in the v7m header match the Cortex-M3 Debug Core Register
-        * Selector values for R0..R15, xPSR, MSP, and PSP.
-        */
-       switch (num) {
-               case 0 ... 18:
-                       /* read a normal core register */
-                       retval = cortexm_dap_read_coreregister_u32(target, value, num);
-
-                       if (retval != ERROR_OK) {
-                               LOG_ERROR("JTAG failure %i", retval);
-                               return ERROR_JTAG_DEVICE_ERROR;
-                       }
-                       LOG_DEBUG("load from core reg %i  value 0x%" PRIx32 "", (int)num, *value);
-                       break;
-
-               case ARMV7M_FPSCR:
-                       /* Floating-point Status and Registers */
-                       retval = target_write_u32(target, DCB_DCRSR, 0x21);
-                       if (retval != ERROR_OK)
-                               return retval;
-                       retval = target_read_u32(target, DCB_DCRDR, value);
-                       if (retval != ERROR_OK)
-                               return retval;
-                       LOG_DEBUG("load from FPSCR  value 0x%" PRIx32, *value);
-                       break;
-
-               case ARMV7M_S0 ... ARMV7M_S31:
-                       /* Floating-point Status and Registers */
-                       retval = target_write_u32(target, DCB_DCRSR, num - ARMV7M_S0 + 0x40);
-                       if (retval != ERROR_OK)
-                               return retval;
-                       retval = target_read_u32(target, DCB_DCRDR, value);
-                       if (retval != ERROR_OK)
-                               return retval;
-                       LOG_DEBUG("load from FPU reg S%d  value 0x%" PRIx32,
-                                 (int)(num - ARMV7M_S0), *value);
-                       break;
-
-               case ARMV7M_PRIMASK:
-               case ARMV7M_BASEPRI:
-               case ARMV7M_FAULTMASK:
-               case ARMV7M_CONTROL:
-                       /* Cortex-M3 packages these four registers as bitfields
-                        * in one Debug Core register.  So say r0 and r2 docs;
-                        * it was removed from r1 docs, but still works.
-                        */
-                       cortexm_dap_read_coreregister_u32(target, value, 20);
-
-                       switch (num) {
-                               case ARMV7M_PRIMASK:
-                                       *value = buf_get_u32((uint8_t *)value, 0, 1);
-                                       break;
+       if (target->debug_reason != DBG_REASON_WATCHPOINT)
+               return ERROR_FAIL;
 
-                               case ARMV7M_BASEPRI:
-                                       *value = buf_get_u32((uint8_t *)value, 8, 8);
-                                       break;
+       struct cortex_m_common *cortex_m = target_to_cm(target);
 
-                               case ARMV7M_FAULTMASK:
-                                       *value = buf_get_u32((uint8_t *)value, 16, 1);
-                                       break;
+       for (struct watchpoint *wp = target->watchpoints; wp; wp = wp->next) {
+               if (!wp->set)
+                       continue;
 
-                               case ARMV7M_CONTROL:
-                                       *value = buf_get_u32((uint8_t *)value, 24, 2);
-                                       break;
-                       }
+               unsigned int dwt_num = wp->set - 1;
+               struct cortex_m_dwt_comparator *comparator = cortex_m->dwt_comparator_list + dwt_num;
 
-                       LOG_DEBUG("load from special reg %i value 0x%" PRIx32 "", (int)num, *value);
-                       break;
+               uint32_t dwt_function;
+               int retval = target_read_u32(target, comparator->dwt_comparator_address + 8, &dwt_function);
+               if (retval != ERROR_OK)
+                       return ERROR_FAIL;
 
-               default:
-                       return ERROR_COMMAND_SYNTAX_ERROR;
+               /* check the MATCHED bit */
+               if (dwt_function & BIT(24)) {
+                       *hit_watchpoint = wp;
+                       return ERROR_OK;
+               }
        }
 
-       return ERROR_OK;
+       return ERROR_FAIL;
 }
 
-static int cortex_m_store_core_reg_u32(struct target *target,
-               uint32_t num, uint32_t value)
+void cortex_m_enable_watchpoints(struct target *target)
 {
-       int retval;
-       uint32_t reg;
-       struct armv7m_common *armv7m = target_to_armv7m(target);
-
-       /* NOTE:  we "know" here that the register identifiers used
-        * in the v7m header match the Cortex-M3 Debug Core Register
-        * Selector values for R0..R15, xPSR, MSP, and PSP.
-        */
-       switch (num) {
-               case 0 ... 18:
-                       retval = cortexm_dap_write_coreregister_u32(target, value, num);
-                       if (retval != ERROR_OK) {
-                               struct reg *r;
-
-                               LOG_ERROR("JTAG failure");
-                               r = armv7m->arm.core_cache->reg_list + num;
-                               r->dirty = r->valid;
-                               return ERROR_JTAG_DEVICE_ERROR;
-                       }
-                       LOG_DEBUG("write core reg %i value 0x%" PRIx32 "", (int)num, value);
-                       break;
-
-               case ARMV7M_FPSCR:
-                       /* Floating-point Status and Registers */
-                       retval = target_write_u32(target, DCB_DCRDR, value);
-                       if (retval != ERROR_OK)
-                               return retval;
-                       retval = target_write_u32(target, DCB_DCRSR, 0x21 | (1<<16));
-                       if (retval != ERROR_OK)
-                               return retval;
-                       LOG_DEBUG("write FPSCR value 0x%" PRIx32, value);
-                       break;
-
-               case ARMV7M_S0 ... ARMV7M_S31:
-                       /* Floating-point Status and Registers */
-                       retval = target_write_u32(target, DCB_DCRDR, value);
-                       if (retval != ERROR_OK)
-                               return retval;
-                       retval = target_write_u32(target, DCB_DCRSR, (num - ARMV7M_S0 + 0x40) | (1<<16));
-                       if (retval != ERROR_OK)
-                               return retval;
-                       LOG_DEBUG("write FPU reg S%d  value 0x%" PRIx32,
-                                 (int)(num - ARMV7M_S0), value);
-                       break;
-
-               case ARMV7M_PRIMASK:
-               case ARMV7M_BASEPRI:
-               case ARMV7M_FAULTMASK:
-               case ARMV7M_CONTROL:
-                       /* Cortex-M3 packages these four registers as bitfields
-                        * in one Debug Core register.  So say r0 and r2 docs;
-                        * it was removed from r1 docs, but still works.
-                        */
-                       cortexm_dap_read_coreregister_u32(target, &reg, 20);
-
-                       switch (num) {
-                               case ARMV7M_PRIMASK:
-                                       buf_set_u32((uint8_t *)&reg, 0, 1, value);
-                                       break;
-
-                               case ARMV7M_BASEPRI:
-                                       buf_set_u32((uint8_t *)&reg, 8, 8, value);
-                                       break;
-
-                               case ARMV7M_FAULTMASK:
-                                       buf_set_u32((uint8_t *)&reg, 16, 1, value);
-                                       break;
-
-                               case ARMV7M_CONTROL:
-                                       buf_set_u32((uint8_t *)&reg, 24, 2, value);
-                                       break;
-                       }
-
-                       cortexm_dap_write_coreregister_u32(target, reg, 20);
-
-                       LOG_DEBUG("write special reg %i value 0x%" PRIx32 " ", (int)num, value);
-                       break;
+       struct watchpoint *watchpoint = target->watchpoints;
 
-               default:
-                       return ERROR_COMMAND_SYNTAX_ERROR;
+       /* set any pending watchpoints */
+       while (watchpoint) {
+               if (!watchpoint->set)
+                       cortex_m_set_watchpoint(target, watchpoint);
+               watchpoint = watchpoint->next;
        }
-
-       return ERROR_OK;
 }
 
 static int cortex_m_read_memory(struct target *target, target_addr_t address,
@@ -1785,7 +1950,7 @@ static int cortex_m_read_memory(struct target *target, target_addr_t address,
 {
        struct armv7m_common *armv7m = target_to_armv7m(target);
 
-       if (armv7m->arm.is_armv6m) {
+       if (armv7m->arm.arch == ARM_ARCH_V6M) {
                /* armv6m does not handle unaligned memory access */
                if (((size == 4) && (address & 0x3u)) || ((size == 2) && (address & 0x1u)))
                        return ERROR_TARGET_UNALIGNED_ACCESS;
@@ -1799,7 +1964,7 @@ static int cortex_m_write_memory(struct target *target, target_addr_t address,
 {
        struct armv7m_common *armv7m = target_to_armv7m(target);
 
-       if (armv7m->arm.is_armv6m) {
+       if (armv7m->arm.arch == ARM_ARCH_V6M) {
                /* armv6m does not handle unaligned memory access */
                if (((size == 4) && (address & 0x3u)) || ((size == 2) && (address & 0x1u)))
                        return ERROR_TARGET_UNALIGNED_ACCESS;
@@ -1835,28 +2000,23 @@ int cortex_m_profiling(struct target *target, uint32_t *samples,
        struct timeval timeout, now;
        struct armv7m_common *armv7m = target_to_armv7m(target);
        uint32_t reg_value;
-       bool use_pcsr = false;
-       int retval = ERROR_OK;
-       struct reg *reg;
-
-       gettimeofday(&timeout, NULL);
-       timeval_add_time(&timeout, seconds, 0);
+       int retval;
 
        retval = target_read_u32(target, DWT_PCSR, &reg_value);
        if (retval != ERROR_OK) {
                LOG_ERROR("Error while reading PCSR");
                return retval;
        }
-
-       if (reg_value != 0) {
-               use_pcsr = true;
-               LOG_INFO("Starting Cortex-M profiling. Sampling DWT_PCSR as fast as we can...");
-       } else {
-               LOG_INFO("Starting profiling. Halting and resuming the"
-                        " target as often as we can...");
-               reg = register_get_by_name(target->reg_cache, "pc", 1);
+       if (reg_value == 0) {
+               LOG_INFO("PCSR sampling not supported on this processor.");
+               return target_profiling_default(target, samples, max_num_samples, num_samples, seconds);
        }
 
+       gettimeofday(&timeout, NULL);
+       timeval_add_time(&timeout, seconds, 0);
+
+       LOG_INFO("Starting Cortex-M profiling. Sampling DWT_PCSR as fast as we can...");
+
        /* Make sure the target is running */
        target_poll(target);
        if (target->state == TARGET_HALTED)
@@ -1870,40 +2030,21 @@ int cortex_m_profiling(struct target *target, uint32_t *samples,
        uint32_t sample_count = 0;
 
        for (;;) {
-               if (use_pcsr) {
-                       if (armv7m && armv7m->debug_ap) {
-                               uint32_t read_count = max_num_samples - sample_count;
-                               if (read_count > 1024)
-                                       read_count = 1024;
-
-                               retval = mem_ap_read_buf_noincr(armv7m->debug_ap,
-                                                       (void *)&samples[sample_count],
-                                                       4, read_count, DWT_PCSR);
-                               sample_count += read_count;
-                       } else {
-                               target_read_u32(target, DWT_PCSR, &samples[sample_count++]);
-                       }
+               if (armv7m && armv7m->debug_ap) {
+                       uint32_t read_count = max_num_samples - sample_count;
+                       if (read_count > 1024)
+                               read_count = 1024;
+
+                       retval = mem_ap_read_buf_noincr(armv7m->debug_ap,
+                                               (void *)&samples[sample_count],
+                                               4, read_count, DWT_PCSR);
+                       sample_count += read_count;
                } else {
-                       target_poll(target);
-                       if (target->state == TARGET_HALTED) {
-                               reg_value = buf_get_u32(reg->value, 0, 32);
-                               /* current pc, addr = 0, do not handle breakpoints, not debugging */
-                               retval = target_resume(target, 1, 0, 0, 0);
-                               samples[sample_count++] = reg_value;
-                               target_poll(target);
-                               alive_sleep(10); /* sleep 10ms, i.e. <100 samples/second. */
-                       } else if (target->state == TARGET_RUNNING) {
-                               /* We want to quickly sample the PC. */
-                               retval = target_halt(target);
-                       } else {
-                               LOG_INFO("Target not halted or running");
-                               retval = ERROR_OK;
-                               break;
-                       }
+                       target_read_u32(target, DWT_PCSR, &samples[sample_count++]);
                }
 
                if (retval != ERROR_OK) {
-                       LOG_ERROR("Error while reading %s", use_pcsr ? "PCSR" : "target pc");
+                       LOG_ERROR("Error while reading PCSR");
                        return retval;
                }
 
@@ -2013,12 +2154,12 @@ static void cortex_m_dwt_addreg(struct target *t, struct reg *r, const struct dw
        r->type = &dwt_reg_type;
 }
 
-void cortex_m_dwt_setup(struct cortex_m_common *cm, struct target *target)
+static void cortex_m_dwt_setup(struct cortex_m_common *cm, struct target *target)
 {
        uint32_t dwtcr;
        struct reg_cache *cache;
        struct cortex_m_dwt_comparator *comparator;
-       int reg, i;
+       int reg;
 
        target_read_u32(target, DWT_CTRL, &dwtcr);
        LOG_DEBUG("DWT_CTRL: 0x%" PRIx32, dwtcr);
@@ -2060,7 +2201,7 @@ fail1:
                        dwt_base_regs + reg);
 
        comparator = cm->dwt_comparator_list;
-       for (i = 0; i < cm->dwt_num_comp; i++, comparator++) {
+       for (unsigned int i = 0; i < cm->dwt_num_comp; i++, comparator++) {
                int j;
 
                comparator->dwt_comparator_address = DWT_COMP0 + 0x10 * i;
@@ -2131,14 +2272,13 @@ int cortex_m_examine(struct target *target)
 {
        int retval;
        uint32_t cpuid, fpcr, mvfr0, mvfr1;
-       int i;
        struct cortex_m_common *cortex_m = target_to_cm(target);
        struct adiv5_dap *swjdp = cortex_m->armv7m.arm.dap;
        struct armv7m_common *armv7m = target_to_armv7m(target);
 
-       /* stlink shares the examine handler but does not support
+       /* hla_target shares the examine handler but does not support
         * all its calls */
-       if (!armv7m->stlink) {
+       if (!armv7m->is_hla_target) {
                if (cortex_m->apsel == DP_APSEL_INVALID) {
                        /* Search for the MEM-AP */
                        retval = cortex_m_find_mem_ap(swjdp, &armv7m->debug_ap);
@@ -2150,7 +2290,6 @@ int cortex_m_examine(struct target *target)
                        armv7m->debug_ap = dap_ap(swjdp, cortex_m->apsel);
                }
 
-               /* Leave (only) generic DAP stuff for debugport_init(); */
                armv7m->debug_ap->memaccess_tck = 8;
 
                retval = mem_ap_init(armv7m->debug_ap);
@@ -2166,35 +2305,31 @@ int cortex_m_examine(struct target *target)
                if (retval != ERROR_OK)
                        return retval;
 
-               /* Get CPU Type */
-               i = (cpuid >> 4) & 0xf;
-
-               /* Check if it is an ARMv8-M core */
-               armv7m->arm.is_armv8m = true;
+               /* Get ARCH and CPU types */
+               const enum cortex_m_partno core_partno = (cpuid & ARM_CPUID_PARTNO_MASK) >> ARM_CPUID_PARTNO_POS;
 
-               switch (cpuid & ARM_CPUID_PARTNO_MASK) {
-                       case CORTEX_M23_PARTNO:
-                               i = 23;
-                               break;
-                       case CORTEX_M33_PARTNO:
-                               i = 33;
-                               break;
-                       case CORTEX_M35P_PARTNO:
-                               i = 35;
-                               break;
-                       case CORTEX_M55_PARTNO:
-                               i = 55;
-                               break;
-                       default:
-                               armv7m->arm.is_armv8m = false;
+               for (unsigned int n = 0; n < ARRAY_SIZE(cortex_m_parts); n++) {
+                       if (core_partno == cortex_m_parts[n].partno) {
+                               cortex_m->core_info = &cortex_m_parts[n];
                                break;
+                       }
                }
 
+               if (!cortex_m->core_info) {
+                       LOG_ERROR("Cortex-M PARTNO 0x%x is unrecognized", core_partno);
+                       return ERROR_FAIL;
+               }
+
+               armv7m->arm.arch = cortex_m->core_info->arch;
+
+               LOG_INFO("%s: %s r%" PRId8 "p%" PRId8 " processor detected",
+                               target_name(target),
+                               cortex_m->core_info->name,
+                               (uint8_t)((cpuid >> 20) & 0xf),
+                               (uint8_t)((cpuid >> 0) & 0xf));
 
-               LOG_DEBUG("Cortex-M%d r%" PRId8 "p%" PRId8 " processor detected",
-                               i, (uint8_t)((cpuid >> 20) & 0xf), (uint8_t)((cpuid >> 0) & 0xf));
                cortex_m->maskints_erratum = false;
-               if (i == 7) {
+               if (core_partno == CORTEX_M7_PARTNO) {
                        uint8_t rev, patch;
                        rev = (cpuid >> 20) & 0xf;
                        patch = (cpuid >> 0) & 0xf;
@@ -2205,65 +2340,55 @@ int cortex_m_examine(struct target *target)
                }
                LOG_DEBUG("cpuid: 0x%8.8" PRIx32 "", cpuid);
 
-               /* VECTRESET is not supported on Cortex-M0, M0+ and M1 */
-               cortex_m->vectreset_supported = i > 1;
-
-               if (i == 4) {
+               if (cortex_m->core_info->flags & CORTEX_M_F_HAS_FPV4) {
                        target_read_u32(target, MVFR0, &mvfr0);
                        target_read_u32(target, MVFR1, &mvfr1);
 
                        /* test for floating point feature on Cortex-M4 */
                        if ((mvfr0 == MVFR0_DEFAULT_M4) && (mvfr1 == MVFR1_DEFAULT_M4)) {
-                               LOG_DEBUG("Cortex-M%d floating point feature FPv4_SP found", i);
-                               armv7m->fp_feature = FPv4_SP;
+                               LOG_DEBUG("%s floating point feature FPv4_SP found", cortex_m->core_info->name);
+                               armv7m->fp_feature = FPV4_SP;
                        }
-               } else if (i == 7 || i == 33 || i == 35 || i == 55) {
+               } else if (cortex_m->core_info->flags & CORTEX_M_F_HAS_FPV5) {
                        target_read_u32(target, MVFR0, &mvfr0);
                        target_read_u32(target, MVFR1, &mvfr1);
 
                        /* test for floating point features on Cortex-M7 */
                        if ((mvfr0 == MVFR0_DEFAULT_M7_SP) && (mvfr1 == MVFR1_DEFAULT_M7_SP)) {
-                               LOG_DEBUG("Cortex-M%d floating point feature FPv5_SP found", i);
-                               armv7m->fp_feature = FPv5_SP;
+                               LOG_DEBUG("%s floating point feature FPv5_SP found", cortex_m->core_info->name);
+                               armv7m->fp_feature = FPV5_SP;
                        } else if ((mvfr0 == MVFR0_DEFAULT_M7_DP) && (mvfr1 == MVFR1_DEFAULT_M7_DP)) {
-                               LOG_DEBUG("Cortex-M%d floating point feature FPv5_DP found", i);
-                               armv7m->fp_feature = FPv5_DP;
+                               LOG_DEBUG("%s floating point feature FPv5_DP found", cortex_m->core_info->name);
+                               armv7m->fp_feature = FPV5_DP;
                        }
-               } else if (i == 0) {
-                       /* Cortex-M0 does not support unaligned memory access */
-                       armv7m->arm.is_armv6m = true;
                }
 
-               if (armv7m->fp_feature == FP_NONE &&
-                   armv7m->arm.core_cache->num_regs > ARMV7M_NUM_CORE_REGS_NOFP) {
-                       /* free unavailable FPU registers */
-                       size_t idx;
-
-                       for (idx = ARMV7M_NUM_CORE_REGS_NOFP;
-                            idx < armv7m->arm.core_cache->num_regs;
-                            idx++) {
-                               free(armv7m->arm.core_cache->reg_list[idx].value);
-                               free(armv7m->arm.core_cache->reg_list[idx].feature);
-                               free(armv7m->arm.core_cache->reg_list[idx].reg_data_type);
-                       }
-                       armv7m->arm.core_cache->num_regs = ARMV7M_NUM_CORE_REGS_NOFP;
-               }
+               /* VECTRESET is supported only on ARMv7-M cores */
+               cortex_m->vectreset_supported = armv7m->arm.arch == ARM_ARCH_V7M;
 
-               if (!armv7m->stlink) {
-                       if (i == 3 || i == 4)
+               /* Check for FPU, otherwise mark FPU register as non-existent */
+               if (armv7m->fp_feature == FP_NONE)
+                       for (size_t idx = ARMV7M_FPU_FIRST_REG; idx <= ARMV7M_FPU_LAST_REG; idx++)
+                               armv7m->arm.core_cache->reg_list[idx].exist = false;
+
+               if (armv7m->arm.arch != ARM_ARCH_V8M)
+                       for (size_t idx = ARMV8M_FIRST_REG; idx <= ARMV8M_LAST_REG; idx++)
+                               armv7m->arm.core_cache->reg_list[idx].exist = false;
+
+               if (!armv7m->is_hla_target) {
+                       if (cortex_m->core_info->flags & CORTEX_M_F_TAR_AUTOINCR_BLOCK_4K)
                                /* Cortex-M3/M4 have 4096 bytes autoincrement range,
                                 * s. ARM IHI 0031C: MEM-AP 7.2.2 */
                                armv7m->debug_ap->tar_autoincr_block = (1 << 12);
-                       else if (i == 7)
-                               /* Cortex-M7 has only 1024 bytes autoincrement range */
-                               armv7m->debug_ap->tar_autoincr_block = (1 << 10);
                }
 
-               /* Enable debug requests */
                retval = target_read_u32(target, DCB_DHCSR, &cortex_m->dcb_dhcsr);
                if (retval != ERROR_OK)
                        return retval;
+               cortex_m_cumulate_dhcsr_sticky(cortex_m, cortex_m->dcb_dhcsr);
+
                if (!(cortex_m->dcb_dhcsr & C_DEBUGEN)) {
+                       /* Enable debug requests */
                        uint32_t dhcsr = (cortex_m->dcb_dhcsr | C_DEBUGEN) & ~(C_HALT | C_STEP | C_MASKINTS);
 
                        retval = target_write_u32(target, DCB_DHCSR, DBGKEY | (dhcsr & 0x0000FFFFUL));
@@ -2277,10 +2402,8 @@ int cortex_m_examine(struct target *target)
                if (retval != ERROR_OK)
                        return retval;
 
-               if (armv7m->trace_config.config_type != TRACE_CONFIG_TYPE_DISABLED) {
-                       armv7m_trace_tpiu_config(target);
+               if (armv7m->trace_config.itm_deferred_config)
                        armv7m_trace_itm_config(target);
-               }
 
                /* NOTE: FPB and DWT are both optional. */
 
@@ -2297,7 +2420,7 @@ int cortex_m_examine(struct target *target)
                                cortex_m->fp_num_code + cortex_m->fp_num_lit,
                                sizeof(struct cortex_m_fp_comparator));
                cortex_m->fpb_enabled = fpcr & 1;
-               for (i = 0; i < cortex_m->fp_num_code + cortex_m->fp_num_lit; i++) {
+               for (unsigned int i = 0; i < cortex_m->fp_num_code + cortex_m->fp_num_lit; i++) {
                        cortex_m->fp_comparator_list[i].type =
                                (i < cortex_m->fp_num_code) ? FPCR_CODE : FPCR_LITERAL;
                        cortex_m->fp_comparator_list[i].fpcr_address = FP_COMP0 + 4 * i;
@@ -2315,7 +2438,7 @@ int cortex_m_examine(struct target *target)
                cortex_m_dwt_setup(cortex_m, target);
 
                /* These hardware breakpoints only work for code in flash! */
-               LOG_INFO("%s: hardware has %d breakpoints, %d watchpoints",
+               LOG_INFO("%s: target has %d breakpoints, %d watchpoints",
                        target_name(target),
                        cortex_m->fp_num_code,
                        cortex_m->dwt_num_comp);
@@ -2445,7 +2568,7 @@ static int cortex_m_target_create(struct target *target, Jim_Interp *interp)
                return ERROR_FAIL;
 
        struct cortex_m_common *cortex_m = calloc(1, sizeof(struct cortex_m_common));
-       if (cortex_m == NULL) {
+       if (!cortex_m) {
                LOG_ERROR("No memory creating target");
                return ERROR_FAIL;
        }
@@ -2463,7 +2586,7 @@ static int cortex_m_target_create(struct target *target, Jim_Interp *interp)
 static int cortex_m_verify_pointer(struct command_invocation *cmd,
        struct cortex_m_common *cm)
 {
-       if (cm->common_magic != CORTEX_M_COMMON_MAGIC) {
+       if (!is_cortex_m_with_dap_access(cm)) {
                command_print(cmd, "target is not a Cortex-M");
                return ERROR_TARGET_INVALID;
        }
@@ -2502,6 +2625,11 @@ COMMAND_HANDLER(handle_cortex_m_vector_catch_command)
        if (retval != ERROR_OK)
                return retval;
 
+       if (!target_was_examined(target)) {
+               LOG_ERROR("Target not examined yet");
+               return ERROR_FAIL;
+       }
+
        retval = mem_ap_read_atomic_u32(armv7m->debug_ap, DCB_DEMCR, &demcr);
        if (retval != ERROR_OK)
                return retval;
@@ -2566,14 +2694,14 @@ COMMAND_HANDLER(handle_cortex_m_mask_interrupts_command)
        struct cortex_m_common *cortex_m = target_to_cm(target);
        int retval;
 
-       static const Jim_Nvp nvp_maskisr_modes[] = {
+       static const struct jim_nvp nvp_maskisr_modes[] = {
                { .name = "auto", .value = CORTEX_M_ISRMASK_AUTO },
                { .name = "off", .value = CORTEX_M_ISRMASK_OFF },
                { .name = "on", .value = CORTEX_M_ISRMASK_ON },
                { .name = "steponly", .value = CORTEX_M_ISRMASK_STEPONLY },
                { .name = NULL, .value = -1 },
        };
-       const Jim_Nvp *n;
+       const struct jim_nvp *n;
 
 
        retval = cortex_m_verify_pointer(CMD, cortex_m);
@@ -2586,14 +2714,14 @@ COMMAND_HANDLER(handle_cortex_m_mask_interrupts_command)
        }
 
        if (CMD_ARGC > 0) {
-               n = Jim_Nvp_name2value_simple(nvp_maskisr_modes, CMD_ARGV[0]);
-               if (n->name == NULL)
+               n = jim_nvp_name2value_simple(nvp_maskisr_modes, CMD_ARGV[0]);
+               if (!n->name)
                        return ERROR_COMMAND_SYNTAX_ERROR;
                cortex_m->isrmasking_mode = n->value;
                cortex_m_set_maskints_for_halt(target);
        }
 
-       n = Jim_Nvp_value2name_simple(nvp_maskisr_modes, cortex_m->isrmasking_mode);
+       n = jim_nvp_value2name_simple(nvp_maskisr_modes, cortex_m->isrmasking_mode);
        command_print(CMD, "cortex_m interrupt mask %s", n->name);
 
        return ERROR_OK;
@@ -2675,6 +2803,11 @@ static const struct command_registration cortex_m_command_handlers[] = {
        {
                .chain = armv7m_trace_command_handlers,
        },
+       /* START_DEPRECATED_TPIU */
+       {
+               .chain = arm_tpiu_deprecated_command_handlers,
+       },
+       /* END_DEPRECATED_TPIU */
        {
                .name = "cortex_m",
                .mode = COMMAND_EXEC,
@@ -2682,12 +2815,14 @@ static const struct command_registration cortex_m_command_handlers[] = {
                .usage = "",
                .chain = cortex_m_exec_command_handlers,
        },
+       {
+               .chain = rtt_target_command_handlers,
+       },
        COMMAND_REGISTRATION_DONE
 };
 
 struct target_type cortexm_target = {
        .name = "cortex_m",
-       .deprecated_name = "cortex_m3",
 
        .poll = cortex_m_poll,
        .arch_state = armv7m_arch_state,
@@ -2718,6 +2853,7 @@ struct target_type cortexm_target = {
        .remove_breakpoint = cortex_m_remove_breakpoint,
        .add_watchpoint = cortex_m_add_watchpoint,
        .remove_watchpoint = cortex_m_remove_watchpoint,
+       .hit_watchpoint = cortex_m_hit_watchpoint,
 
        .commands = cortex_m_command_handlers,
        .target_create = cortex_m_target_create,