X-Git-Url: https://git.sur5r.net/?a=blobdiff_plain;f=src%2Ftarget%2Fcortex_m3.c;h=48f811489f870929b396f31c0613d60d42268b7a;hb=d91941d5a01ca0b9d43571edc03ba18741076cca;hp=9685821977e0e97c6b622b98a992b6b5ebf6a34f;hpb=ec88ccc51cb5d8594ae95660c826954f3a9042ec;p=openocd diff --git a/src/target/cortex_m3.c b/src/target/cortex_m3.c index 96858219..48f81148 100644 --- a/src/target/cortex_m3.c +++ b/src/target/cortex_m3.c @@ -185,11 +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); @@ -204,21 +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... @@ -533,7 +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); @@ -782,14 +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); } @@ -1938,12 +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++) @@ -1989,24 +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 = "
[]", + .usage = "address [count]", }, { .name = "maskisr", - .handler = &handle_cortex_m3_mask_interrupts_command, + .handler = handle_cortex_m3_mask_interrupts_command, .mode = COMMAND_EXEC, .help = "mask cortex_m3 interrupts", .usage = "['on'|'off']", }, { .name = "vector_catch", - .handler = &handle_cortex_m3_vector_catch_command, + .handler = handle_cortex_m3_vector_catch_command, .mode = COMMAND_EXEC, - .help = "catch hardware vectors", - .usage = "['all'|'none'|]", + .help = "configure hardware vectors to trigger debug entry", + .usage = "['all'|'none'|('bus_err'|'chk_err'|...)*]", }, COMMAND_REGISTRATION_DONE };