#include "log.h"
+/*
+ * This disassembler supports two main functions for OpenOCD:
+ *
+ * - Various "disassemble" commands. OpenOCD can serve as a
+ * machine-language debugger, without help from GDB.
+ *
+ * - Single stepping. Not all ARM cores support hardware single
+ * stepping. To work without that support, the debugger must
+ * be able to decode instructions to find out where to put a
+ * "next instruction" breakpoint.
+ *
+ * In addition, interpretation of ETM trace data needs some of the
+ * decoding mechanisms.
+ *
+ * At this writing (September 2009) neither function is complete.
+ *
+ * - ARM decoding
+ * * Old-style syntax (not UAL) is generally used
+ * * VFP instructions are not understood (ARMv5 and later)
+ * except as coprocessor 10/11 operations
+ * * Most ARM instructions through ARMv6 are decoded, but some
+ * of the post-ARMv4 opcodes may not be handled yet
+ * * NEON instructions are not understood (ARMv7-A)
+ *
+ * - Thumb/Thumb2 decoding
+ * * UAL syntax should be consistently used
+ * * Any Thumb2 instructions used in Cortex-M3 (ARMv7-M) should
+ * be handled properly. Accordingly, so should the subset
+ * used in Cortex-M0/M1; and "original" 16-bit Thumb from
+ * ARMv4T and ARMv5T.
+ * * Conditional effects of Thumb2 "IT" (if-then) instructions
+ * are not handled: the affected instructions are not shown
+ * with their now-conditional suffixes.
+ * * Some ARMv6 and ARMv7-M Thumb2 instructions may not be
+ * handled (minimally for coprocessor access).
+ * * SIMD instructions, and some other Thumb2 instructions
+ * from ARMv7-A, are not understood.
+ *
+ * - ThumbEE decoding
+ * * As a Thumb2 variant, the Thumb2 comments (above) apply.
+ * * Opcodes changed by ThumbEE mode are not handled; these
+ * instructions wrongly decode as LDM and STM.
+ *
+ * - Jazelle decoding ... no support whatsoever for Jazelle mode
+ * or decoding. ARM encourages use of the more generic ThumbEE
+ * mode, instead of Jazelle mode, in current chips.
+ *
+ * - Single-step/emulation ... spotty support, which is only weakly
+ * tested. Thumb2 is not supported. (Arguably a full simulator
+ * is not needed to support just single stepping. Recognizing
+ * branch vs non-branch instructions suffices, except when the
+ * instruction faults and triggers a synchronous exception which
+ * can be intercepted using other means.)
+ *
+ * ARM DDI 0406B "ARM Architecture Reference Manual, ARM v7-A and
+ * ARM v7-R edition" gives the most complete coverage of the various
+ * generations of ARM instructions. At this writing it is publicly
+ * accessible to anyone willing to create an account at the ARM
+ * web site; see http://www.arm.com/documentation/ for information.
+ *
+ * ARM DDI 0403C "ARMv7-M Architecture Reference Manual" provides
+ * more details relevant to the Thumb2-only processors (such as
+ * the Cortex-M implementations).
+ */
+
/* textual represenation of the condition field */
/* ALways (default) is ommitted (empty string) */
-char *arm_condition_strings[] =
+static const char *arm_condition_strings[] =
{
"EQ", "NE", "CS", "CC", "MI", "PL", "VS", "VC", "HI", "LS", "GE", "LT", "GT", "LE", "", "NV"
};
/* make up for C's missing ROR */
-uint32_t ror(uint32_t value, int places)
+static uint32_t ror(uint32_t value, int places)
{
return (value >> places) | (value << (32 - places));
}
-int evaluate_pld(uint32_t opcode, uint32_t address, arm_instruction_t *instruction)
+static int evaluate_pld(uint32_t opcode,
+ uint32_t address, arm_instruction_t *instruction)
{
/* PLD */
- if ((opcode & 0x0d70f0000) == 0x0550f000)
+ if ((opcode & 0x0d70f000) == 0x0550f000)
{
instruction->type = ARM_PLD;
return -1;
}
-int evaluate_swi(uint32_t opcode, uint32_t address, arm_instruction_t *instruction)
+static int evaluate_swi(uint32_t opcode,
+ uint32_t address, arm_instruction_t *instruction)
{
instruction->type = ARM_SWI;
return ERROR_OK;
}
-int evaluate_blx_imm(uint32_t opcode, uint32_t address, arm_instruction_t *instruction)
+static int evaluate_blx_imm(uint32_t opcode,
+ uint32_t address, arm_instruction_t *instruction)
{
int offset;
uint32_t immediate;
return ERROR_OK;
}
-int evaluate_b_bl(uint32_t opcode, uint32_t address, arm_instruction_t *instruction)
+static int evaluate_b_bl(uint32_t opcode,
+ uint32_t address, arm_instruction_t *instruction)
{
uint8_t L;
uint32_t immediate;
/* Coprocessor load/store and double register transfers */
/* both normal and extended instruction space (condition field b1111) */
-int evaluate_ldc_stc_mcrr_mrrc(uint32_t opcode, uint32_t address, arm_instruction_t *instruction)
+static int evaluate_ldc_stc_mcrr_mrrc(uint32_t opcode,
+ uint32_t address, arm_instruction_t *instruction)
{
uint8_t cp_num = (opcode & 0xf00) >> 8;
/* Coprocessor data processing instructions */
/* Coprocessor register transfer instructions */
/* both normal and extended instruction space (condition field b1111) */
-int evaluate_cdp_mcr_mrc(uint32_t opcode, uint32_t address, arm_instruction_t *instruction)
+static int evaluate_cdp_mcr_mrc(uint32_t opcode,
+ uint32_t address, arm_instruction_t *instruction)
{
- char* cond;
+ const char *cond;
char* mnemonic;
uint8_t cp_num, opcode_1, CRd_Rd, CRn, CRm, opcode_2;
}
/* Load/store instructions */
-int evaluate_load_store(uint32_t opcode, uint32_t address, arm_instruction_t *instruction)
+static int evaluate_load_store(uint32_t opcode,
+ uint32_t address, arm_instruction_t *instruction)
{
uint8_t I, P, U, B, W, L;
uint8_t Rn, Rd;
case 2:
type = "B";
break;
- case 3:
+ default:
type = "H";
break;
}
case 2:
rot = ", ROR #16";
break;
- case 3:
+ default:
rot = ", ROR #24";
break;
}
}
/* Miscellaneous load/store instructions */
-int evaluate_misc_load_store(uint32_t opcode, uint32_t address, arm_instruction_t *instruction)
+static int evaluate_misc_load_store(uint32_t opcode,
+ uint32_t address, arm_instruction_t *instruction)
{
uint8_t P, U, I, W, L, S, H;
uint8_t Rn, Rd;
}
/* Load/store multiples instructions */
-int evaluate_ldm_stm(uint32_t opcode, uint32_t address, arm_instruction_t *instruction)
+static int evaluate_ldm_stm(uint32_t opcode,
+ uint32_t address, arm_instruction_t *instruction)
{
uint8_t P, U, S, W, L, Rn;
uint32_t register_list;
}
/* Multiplies, extra load/stores */
-int evaluate_mul_and_extra_ld_st(uint32_t opcode, uint32_t address, arm_instruction_t *instruction)
+static int evaluate_mul_and_extra_ld_st(uint32_t opcode,
+ uint32_t address, arm_instruction_t *instruction)
{
/* Multiply (accumulate) (long) and Swap/swap byte */
if ((opcode & 0x000000f0) == 0x00000090)
return evaluate_misc_load_store(opcode, address, instruction);
}
-int evaluate_mrs_msr(uint32_t opcode, uint32_t address, arm_instruction_t *instruction)
+static int evaluate_mrs_msr(uint32_t opcode,
+ uint32_t address, arm_instruction_t *instruction)
{
int R = (opcode & 0x00400000) >> 22;
char *PSR = (R) ? "SPSR" : "CPSR";
}
/* Miscellaneous instructions */
-int evaluate_misc_instr(uint32_t opcode, uint32_t address, arm_instruction_t *instruction)
+static int evaluate_misc_instr(uint32_t opcode,
+ uint32_t address, arm_instruction_t *instruction)
{
/* MRS/MSR */
if ((opcode & 0x000000f0) == 0x00000000)
return ERROR_OK;
}
-int evaluate_data_proc(uint32_t opcode, uint32_t address, arm_instruction_t *instruction)
+static int evaluate_data_proc(uint32_t opcode,
+ uint32_t address, arm_instruction_t *instruction)
{
uint8_t I, op, S, Rn, Rd;
char *mnemonic = NULL;
return -1;
}
-int evaluate_b_bl_blx_thumb(uint16_t opcode, uint32_t address, arm_instruction_t *instruction)
+static int evaluate_b_bl_blx_thumb(uint16_t opcode,
+ uint32_t address, arm_instruction_t *instruction)
{
uint32_t offset = opcode & 0x7ff;
uint32_t opc = (opcode >> 11) & 0x3;
case 1:
instruction->type = ARM_BLX;
mnemonic = "BLX";
+ target_address &= 0xfffffffc;
break;
/* BL/BLX prefix */
case 2:
return ERROR_OK;
}
-int evaluate_add_sub_thumb(uint16_t opcode, uint32_t address, arm_instruction_t *instruction)
+static int evaluate_add_sub_thumb(uint16_t opcode,
+ uint32_t address, arm_instruction_t *instruction)
{
uint8_t Rd = (opcode >> 0) & 0x7;
uint8_t Rn = (opcode >> 3) & 0x7;
return ERROR_OK;
}
-int evaluate_shift_imm_thumb(uint16_t opcode, uint32_t address, arm_instruction_t *instruction)
+static int evaluate_shift_imm_thumb(uint16_t opcode,
+ uint32_t address, arm_instruction_t *instruction)
{
uint8_t Rd = (opcode >> 0) & 0x7;
uint8_t Rm = (opcode >> 3) & 0x7;
return ERROR_OK;
}
-int evaluate_data_proc_imm_thumb(uint16_t opcode, uint32_t address, arm_instruction_t *instruction)
+static int evaluate_data_proc_imm_thumb(uint16_t opcode,
+ uint32_t address, arm_instruction_t *instruction)
{
uint8_t imm = opcode & 0xff;
uint8_t Rd = (opcode >> 8) & 0x7;
return ERROR_OK;
}
-int evaluate_data_proc_thumb(uint16_t opcode, uint32_t address, arm_instruction_t *instruction)
+static int evaluate_data_proc_thumb(uint16_t opcode,
+ uint32_t address, arm_instruction_t *instruction)
{
uint8_t high_reg, op, Rm, Rd,H1,H2;
char *mnemonic = NULL;
return (addr + 4) & ~3;
}
-int evaluate_load_literal_thumb(uint16_t opcode, uint32_t address, arm_instruction_t *instruction)
+static int evaluate_load_literal_thumb(uint16_t opcode,
+ uint32_t address, arm_instruction_t *instruction)
{
uint32_t immediate;
uint8_t Rd = (opcode >> 8) & 0x7;
return ERROR_OK;
}
-int evaluate_load_store_reg_thumb(uint16_t opcode, uint32_t address, arm_instruction_t *instruction)
+static int evaluate_load_store_reg_thumb(uint16_t opcode,
+ uint32_t address, arm_instruction_t *instruction)
{
uint8_t Rd = (opcode >> 0) & 0x7;
uint8_t Rn = (opcode >> 3) & 0x7;
return ERROR_OK;
}
-int evaluate_load_store_imm_thumb(uint16_t opcode, uint32_t address, arm_instruction_t *instruction)
+static int evaluate_load_store_imm_thumb(uint16_t opcode,
+ uint32_t address, arm_instruction_t *instruction)
{
uint32_t offset = (opcode >> 6) & 0x1f;
uint8_t Rd = (opcode >> 0) & 0x7;
return ERROR_OK;
}
-int evaluate_load_store_stack_thumb(uint16_t opcode, uint32_t address, arm_instruction_t *instruction)
+static int evaluate_load_store_stack_thumb(uint16_t opcode,
+ uint32_t address, arm_instruction_t *instruction)
{
uint32_t offset = opcode & 0xff;
uint8_t Rd = (opcode >> 8) & 0x7;
return ERROR_OK;
}
-int evaluate_add_sp_pc_thumb(uint16_t opcode, uint32_t address, arm_instruction_t *instruction)
+static int evaluate_add_sp_pc_thumb(uint16_t opcode,
+ uint32_t address, arm_instruction_t *instruction)
{
uint32_t imm = opcode & 0xff;
uint8_t Rd = (opcode >> 8) & 0x7;
return ERROR_OK;
}
-int evaluate_adjust_stack_thumb(uint16_t opcode, uint32_t address, arm_instruction_t *instruction)
+static int evaluate_adjust_stack_thumb(uint16_t opcode,
+ uint32_t address, arm_instruction_t *instruction)
{
uint32_t imm = opcode & 0x7f;
uint8_t opc = opcode & (1 << 7);
return ERROR_OK;
}
-int evaluate_breakpoint_thumb(uint16_t opcode, uint32_t address, arm_instruction_t *instruction)
+static int evaluate_breakpoint_thumb(uint16_t opcode,
+ uint32_t address, arm_instruction_t *instruction)
{
uint32_t imm = opcode & 0xff;
return ERROR_OK;
}
-int evaluate_load_store_multiple_thumb(uint16_t opcode, uint32_t address, arm_instruction_t *instruction)
+static int evaluate_load_store_multiple_thumb(uint16_t opcode,
+ uint32_t address, arm_instruction_t *instruction)
{
uint32_t reg_list = opcode & 0xff;
uint32_t L = opcode & (1 << 11);
char ptr_name[7] = "";
int i;
+ /* REVISIT: in ThumbEE mode, there are no LDM or STM instructions.
+ * The STMIA and LDMIA opcodes are used for other instructions.
+ */
+
if ((opcode & 0xf000) == 0xc000)
{ /* generic load/store multiple */
char *wback = "!";
return ERROR_OK;
}
-int evaluate_cond_branch_thumb(uint16_t opcode, uint32_t address, arm_instruction_t *instruction)
+static int evaluate_cond_branch_thumb(uint16_t opcode,
+ uint32_t address, arm_instruction_t *instruction)
{
uint32_t offset = opcode & 0xff;
uint8_t cond = (opcode >> 8) & 0xf;
const char *mnemonic;
switch ((opcode >> 4) & 0x0f) {
+ case 0:
+ mnemonic = "LEAVEX";
+ break;
+ case 1:
+ mnemonic = "ENTERX";
+ break;
case 2:
mnemonic = "CLREX";
break;
return t2ev_hint(opcode, address, instruction, cp);
case 0x3b:
return t2ev_misc(opcode, address, instruction, cp);
+ case 0x3c:
+ sprintf(cp, "BXJ\tr%d", (int) (opcode >> 16) & 0x0f);
+ return ERROR_OK;
case 0x3e:
case 0x3f:
sprintf(cp, "MRS\tr%d, %s", (int) (opcode >> 8) & 0x0f,
projects / fw / openocd / blobdiff