/* 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
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);
/* 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...
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);
/* set any pending breakpoints */
while (breakpoint)
{
- if (breakpoint->set == 0)
+ if (!breakpoint->set)
cortex_m3_set_breakpoint(target, breakpoint);
breakpoint = breakpoint->next;
}
/* 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);
}
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)",
}
}
}
- breakpoint->set = 0;
+ breakpoint->set = false;
return ERROR_OK;
}
target_write_u32(target, comparator->dwt_comparator_address + 8,
comparator->function);
- watchpoint->set = 0;
+ watchpoint->set = false;
return ERROR_OK;
}
/* set any pending watchpoints */
while (watchpoint)
{
- if (watchpoint->set == 0)
+ if (!watchpoint->set)
cortex_m3_set_watchpoint(target, watchpoint);
watchpoint = watchpoint->next;
}
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. */
}
}
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++)
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 = "<address> [<count>]",
+ .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'|<list>]",
+ .help = "configure hardware vectors to trigger debug entry",
+ .usage = "['all'|'none'|('bus_err'|'chk_err'|...)*]",
},
COMMAND_REGISTRATION_DONE
};
projects / openocd / blobdiff