X-Git-Url: https://git.sur5r.net/?a=blobdiff_plain;f=src%2Ftarget%2Fcortex_m3.c;h=48f811489f870929b396f31c0613d60d42268b7a;hb=d91941d5a01ca0b9d43571edc03ba18741076cca;hp=556928f826044954916fe21e45c46930fe82729c;hpb=b3bf1d12b2fdfba1c1cbee3e1afbfbb27cbd1a26;p=openocd diff --git a/src/target/cortex_m3.c b/src/target/cortex_m3.c index 556928f8..48f81148 100644 --- a/src/target/cortex_m3.c +++ b/src/target/cortex_m3.c @@ -42,6 +42,9 @@ /* NOTE: most of this should work fine for the Cortex-M1 and * Cortex-M0 cores too, although they're ARMv6-M not ARMv7-M. + * Some differences: M0/M1 doesn't have FBP remapping or the + * DWT tracing/profiling support. (So the cycle counter will + * not be usable; the other stuff isn't currently used here.) * * Although there are some workarounds for errata seen only in r0p0 * silicon, such old parts are hard to find and thus not much tested @@ -182,11 +185,12 @@ static int cortex_m3_endreset_event(struct target *target) int i; uint32_t dcb_demcr; struct cortex_m3_common *cortex_m3 = target_to_cm3(target); + struct armv7m_common *armv7m = &cortex_m3->armv7m; struct swjdp_common *swjdp = &cortex_m3->armv7m.swjdp_info; struct cortex_m3_fp_comparator *fp_list = cortex_m3->fp_comparator_list; struct cortex_m3_dwt_comparator *dwt_list = cortex_m3->dwt_comparator_list; - /* FIXME handling of DEMCR clobbers vector_catch config ... */ + /* REVISIT The four debug monitor bits are currently ignored... */ mem_ap_read_atomic_u32(swjdp, DCB_DEMCR, &dcb_demcr); LOG_DEBUG("DCB_DEMCR = 0x%8.8" PRIx32 "",dcb_demcr); @@ -201,21 +205,14 @@ static int cortex_m3_endreset_event(struct target *target) /* clear any interrupt masking */ cortex_m3_write_debug_halt_mask(target, 0, C_MASKINTS); - /* Enable trace and DWT; trap hard and bus faults. + /* Enable features controlled by ITM and DWT blocks, and catch only + * the vectors we were told to pay attention to. * - * REVISIT why trap those two? And why trash the vector_catch - * config, instead of preserving it? Catching HARDERR and BUSERR - * will interfere with code that handles those itself... + * Target firmware is responsible for all fault handling policy + * choices *EXCEPT* explicitly scripted overrides like "vector_catch" + * or manual updates to the NVIC SHCSR and CCR registers. */ - mem_ap_write_u32(swjdp, DCB_DEMCR, TRCENA | VC_HARDERR | VC_BUSERR); - - /* Monitor bus faults as such (instead of as generic HARDERR), but - * leave memory management and usage faults disabled. - * - * REVISIT setting BUSFAULTENA interferes with code which relies - * on the default setting. Why do it? - */ - mem_ap_write_u32(swjdp, NVIC_SHCSR, SHCSR_BUSFAULTENA); + mem_ap_write_u32(swjdp, DCB_DEMCR, TRCENA | armv7m->demcr); /* Paranoia: evidently some (early?) chips don't preserve all the * debug state (including FBP, DWT, etc) across reset... @@ -530,7 +527,7 @@ static int cortex_m3_soft_reset_halt(struct target *target) uint32_t dcb_dhcsr = 0; int retval, timeout = 0; - /* Enter debug state on reset; see end_reset_event() */ + /* Enter debug state on reset; restore DEMCR in endreset_event() */ mem_ap_write_u32(swjdp, DCB_DEMCR, TRCENA | VC_HARDERR | VC_BUSERR | VC_CORERESET); @@ -579,7 +576,7 @@ static void cortex_m3_enable_breakpoints(struct target *target) /* set any pending breakpoints */ while (breakpoint) { - if (breakpoint->set == 0) + if (!breakpoint->set) cortex_m3_set_breakpoint(target, breakpoint); breakpoint = breakpoint->next; } @@ -779,14 +776,15 @@ static int cortex_m3_assert_reset(struct target *target) /* clear C_HALT in dhcsr reg */ cortex_m3_write_debug_halt_mask(target, 0, C_HALT); - - /* Enter debug state on reset, cf. end_reset_event() */ - mem_ap_write_u32(swjdp, DCB_DEMCR, - TRCENA | VC_HARDERR | VC_BUSERR); } else { - /* Enter debug state on reset, cf. end_reset_event() */ + /* Halt in debug on reset; endreset_event() restores DEMCR. + * + * REVISIT catching BUSERR presumably helps to defend against + * bad vector table entries. Should this include MMERR or + * other flags too? + */ mem_ap_write_atomic_u32(swjdp, DCB_DEMCR, TRCENA | VC_HARDERR | VC_BUSERR | VC_CORERESET); } @@ -936,16 +934,25 @@ cortex_m3_set_breakpoint(struct target *target, struct breakpoint *breakpoint) else if (breakpoint->type == BKPT_SOFT) { uint8_t code[4]; + + /* NOTE: on ARMv6-M and ARMv7-M, BKPT(0xab) is used for + * semihosting; don't use that. Otherwise the BKPT + * parameter is arbitrary. + */ buf_set_u32(code, 0, 32, ARMV5_T_BKPT(0x11)); - if ((retval = target_read_memory(target, breakpoint->address & 0xFFFFFFFE, breakpoint->length, 1, breakpoint->orig_instr)) != ERROR_OK) - { + retval = target_read_memory(target, + breakpoint->address & 0xFFFFFFFE, + breakpoint->length, 1, + breakpoint->orig_instr); + if (retval != ERROR_OK) return retval; - } - if ((retval = target_write_memory(target, breakpoint->address & 0xFFFFFFFE, breakpoint->length, 1, code)) != ERROR_OK) - { + retval = target_write_memory(target, + breakpoint->address & 0xFFFFFFFE, + breakpoint->length, 1, + code); + if (retval != ERROR_OK) return retval; - } - breakpoint->set = 0x11; /* Any nice value but 0 */ + breakpoint->set = true; } LOG_DEBUG("BPID: %d, Type: %d, Address: 0x%08" PRIx32 " Length: %d (set=%d)", @@ -1008,7 +1015,7 @@ cortex_m3_unset_breakpoint(struct target *target, struct breakpoint *breakpoint) } } } - breakpoint->set = 0; + breakpoint->set = false; return ERROR_OK; } @@ -1187,7 +1194,7 @@ cortex_m3_unset_watchpoint(struct target *target, struct watchpoint *watchpoint) target_write_u32(target, comparator->dwt_comparator_address + 8, comparator->function); - watchpoint->set = 0; + watchpoint->set = false; return ERROR_OK; } @@ -1273,7 +1280,7 @@ static void cortex_m3_enable_watchpoints(struct target *target) /* set any pending watchpoints */ while (watchpoint) { - if (watchpoint->set == 0) + if (!watchpoint->set) cortex_m3_set_watchpoint(target, watchpoint); watchpoint = watchpoint->next; } @@ -1647,7 +1654,8 @@ static int cortex_m3_examine(struct target *target) return retval; if (((cpuid >> 4) & 0xc3f) == 0xc23) - LOG_DEBUG("CORTEX-M3 processor detected"); + LOG_DEBUG("Cortex-M3 r%dp%d processor detected", + (cpuid >> 20) & 0xf, (cpuid >> 0) & 0xf); LOG_DEBUG("cpuid: 0x%8.8" PRIx32 "", cpuid); /* NOTE: FPB and DWT are both optional. */ @@ -1925,12 +1933,20 @@ COMMAND_HANDLER(handle_cortex_m3_vector_catch_command) } } write: + /* For now, armv7m->demcr only stores vector catch flags. */ + armv7m->demcr = catch; + demcr &= ~0xffff; demcr |= catch; - /* write, but don't assume it stuck */ + /* write, but don't assume it stuck (why not??) */ mem_ap_write_u32(swjdp, DCB_DEMCR, demcr); mem_ap_read_atomic_u32(swjdp, DCB_DEMCR, &demcr); + + /* FIXME be sure to clear DEMCR on clean server shutdown. + * Otherwise the vector catch hardware could fire when there's + * no debugger hooked up, causing much confusion... + */ } for (unsigned i = 0; i < ARRAY_SIZE(vec_ids); i++) @@ -1976,24 +1992,24 @@ COMMAND_HANDLER(handle_cortex_m3_mask_interrupts_command) static const struct command_registration cortex_m3_exec_command_handlers[] = { { .name = "disassemble", - .handler = &handle_cortex_m3_disassemble_command, + .handler = handle_cortex_m3_disassemble_command, .mode = COMMAND_EXEC, .help = "disassemble Thumb2 instructions", - .usage = "
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