From 57e12b7e452b0f397ca3e1501ef1a2eb61f5a9aa Mon Sep 17 00:00:00 2001 From: oharboe Date: Tue, 8 Sep 2009 06:17:33 +0000 Subject: [PATCH] David Brownell lean up some loose ends with the ARM disassembler - Add a header comment describing its current state and uses and referencing the now-generally-available V7 arch spec - Support some mode switch instructions: * Thumb to Jazelle (BXJ) * Thumb to ThumbEE (ENTERX) * ThumbEE to Thumb (LEAVEX) - Improve that recent warning fix (and associated whitespace goof) - Declare the rest of the internal code and data "static". A compiler may use this, and it helps clarify the scope of these routines (e.g. what changes to them could affect). git-svn-id: svn://svn.berlios.de/openocd/trunk@2675 b42882b7-edfa-0310-969c-e2dbd0fdcd60 --- src/target/arm_disassembler.c | 172 +++++++++++++++++++++++++++------- 1 file changed, 137 insertions(+), 35 deletions(-) diff --git a/src/target/arm_disassembler.c b/src/target/arm_disassembler.c index 3da2127fac..2755cc292f 100644 --- a/src/target/arm_disassembler.c +++ b/src/target/arm_disassembler.c @@ -28,20 +28,86 @@ #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) @@ -62,7 +128,8 @@ int evaluate_pld(uint32_t opcode, uint32_t address, arm_instruction_t *instructi 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; @@ -73,7 +140,8 @@ int evaluate_swi(uint32_t opcode, uint32_t address, arm_instruction_t *instructi 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; @@ -105,7 +173,8 @@ int evaluate_blx_imm(uint32_t opcode, uint32_t address, arm_instruction_t *instr 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; @@ -142,7 +211,8 @@ int evaluate_b_bl(uint32_t opcode, uint32_t address, arm_instruction_t *instruct /* 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; @@ -222,9 +292,10 @@ int evaluate_ldc_stc_mcrr_mrrc(uint32_t opcode, uint32_t address, arm_instructio /* 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; @@ -271,7 +342,8 @@ int evaluate_cdp_mcr_mrc(uint32_t opcode, uint32_t address, arm_instruction_t *i } /* 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; @@ -445,9 +517,6 @@ static int evaluate_extend(uint32_t opcode, uint32_t address, char *cp) unsigned rn = (opcode >> 16) & 0xf; char *type, *rot; - /* GCC 'uninitialized warning removal' */ - type = rot = NULL; - switch ((opcode >> 24) & 0x3) { case 0: type = "B16"; @@ -458,7 +527,7 @@ static int evaluate_extend(uint32_t opcode, uint32_t address, char *cp) case 2: type = "B"; break; - case 3: + default: type = "H"; break; } @@ -473,7 +542,7 @@ static int evaluate_extend(uint32_t opcode, uint32_t address, char *cp) case 2: rot = ", ROR #16"; break; - case 3: + default: rot = ", ROR #24"; break; } @@ -759,7 +828,8 @@ undef: } /* 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; @@ -886,7 +956,8 @@ int evaluate_misc_load_store(uint32_t opcode, uint32_t address, arm_instruction_ } /* 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; @@ -974,7 +1045,8 @@ int evaluate_ldm_stm(uint32_t opcode, uint32_t address, arm_instruction_t *instr } /* 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) @@ -1065,7 +1137,8 @@ int evaluate_mul_and_extra_ld_st(uint32_t opcode, uint32_t address, arm_instruct 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"; @@ -1119,7 +1192,8 @@ int evaluate_mrs_msr(uint32_t opcode, uint32_t address, arm_instruction_t *instr } /* 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) @@ -1309,7 +1383,8 @@ int evaluate_misc_instr(uint32_t opcode, uint32_t address, arm_instruction_t *in 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; @@ -1668,7 +1743,8 @@ int arm_evaluate_opcode(uint32_t opcode, uint32_t address, arm_instruction_t *in 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; @@ -1721,7 +1797,8 @@ int evaluate_b_bl_blx_thumb(uint16_t opcode, uint32_t address, arm_instruction_t 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; @@ -1766,7 +1843,8 @@ int evaluate_add_sub_thumb(uint16_t opcode, uint32_t address, arm_instruction_t 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; @@ -1811,7 +1889,8 @@ int evaluate_shift_imm_thumb(uint16_t opcode, uint32_t address, arm_instruction_ 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; @@ -1853,7 +1932,8 @@ int evaluate_data_proc_imm_thumb(uint16_t opcode, uint32_t address, arm_instruct 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; @@ -2038,7 +2118,8 @@ static inline uint32_t thumb_alignpc4(uint32_t addr) 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; @@ -2062,7 +2143,8 @@ int evaluate_load_literal_thumb(uint16_t opcode, uint32_t address, arm_instructi 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; @@ -2119,7 +2201,8 @@ int evaluate_load_store_reg_thumb(uint16_t opcode, uint32_t address, arm_instruc 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; @@ -2165,7 +2248,8 @@ int evaluate_load_store_imm_thumb(uint16_t opcode, uint32_t address, arm_instruc 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; @@ -2196,7 +2280,8 @@ int evaluate_load_store_stack_thumb(uint16_t opcode, uint32_t address, arm_instr 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; @@ -2229,7 +2314,8 @@ int evaluate_add_sp_pc_thumb(uint16_t opcode, uint32_t address, arm_instruction_ 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); @@ -2259,7 +2345,8 @@ int evaluate_adjust_stack_thumb(uint16_t opcode, uint32_t address, arm_instructi 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; @@ -2272,7 +2359,8 @@ int evaluate_breakpoint_thumb(uint16_t opcode, uint32_t address, arm_instruction 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); @@ -2285,6 +2373,10 @@ int evaluate_load_store_multiple_thumb(uint16_t opcode, uint32_t address, arm_in 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 = "!"; @@ -2345,7 +2437,8 @@ int evaluate_load_store_multiple_thumb(uint16_t opcode, uint32_t address, arm_in 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; @@ -2835,6 +2928,12 @@ static int t2ev_misc(uint32_t opcode, uint32_t address, const char *mnemonic; switch ((opcode >> 4) & 0x0f) { + case 0: + mnemonic = "LEAVEX"; + break; + case 1: + mnemonic = "ENTERX"; + break; case 2: mnemonic = "CLREX"; break; @@ -2888,6 +2987,9 @@ static int t2ev_b_misc(uint32_t opcode, uint32_t address, 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, -- 2.30.2