coding style: add parenthesis around the argument of sizeof
[fw/openocd] / src / target / cortex_m.c
index 03dc515729bacad85fae0177f06acf0e9a8f8019..27febd3d779adf83dceae2f85b4d8553975a841d 100644 (file)
@@ -42,7 +42,7 @@
 
 /* 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
+ * Some differences:  M0/M1 doesn't have FPB remapping or the
  * DWT tracing/profiling support.  (So the cycle counter will
  * not be usable; the other stuff isn't currently used here.)
  *
@@ -136,6 +136,83 @@ static int cortex_m_write_debug_halt_mask(struct target *target,
        return mem_ap_write_atomic_u32(armv7m->debug_ap, DCB_DHCSR, cortex_m->dcb_dhcsr);
 }
 
+static int cortex_m_set_maskints(struct target *target, bool mask)
+{
+       struct cortex_m_common *cortex_m = target_to_cm(target);
+       if (!!(cortex_m->dcb_dhcsr & C_MASKINTS) != mask)
+               return cortex_m_write_debug_halt_mask(target, mask ? C_MASKINTS : 0, mask ? 0 : C_MASKINTS);
+       else
+               return ERROR_OK;
+}
+
+static int cortex_m_set_maskints_for_halt(struct target *target)
+{
+       struct cortex_m_common *cortex_m = target_to_cm(target);
+       switch (cortex_m->isrmasking_mode) {
+               case CORTEX_M_ISRMASK_AUTO:
+                       /* interrupts taken at resume, whether for step or run -> no mask */
+                       return cortex_m_set_maskints(target, false);
+
+               case CORTEX_M_ISRMASK_OFF:
+                       /* interrupts never masked */
+                       return cortex_m_set_maskints(target, false);
+
+               case CORTEX_M_ISRMASK_ON:
+                       /* interrupts always masked */
+                       return cortex_m_set_maskints(target, true);
+
+               case CORTEX_M_ISRMASK_STEPONLY:
+                       /* interrupts masked for single step only -> mask now if MASKINTS
+                        * erratum, otherwise only mask before stepping */
+                       return cortex_m_set_maskints(target, cortex_m->maskints_erratum);
+       }
+       return ERROR_OK;
+}
+
+static int cortex_m_set_maskints_for_run(struct target *target)
+{
+       switch (target_to_cm(target)->isrmasking_mode) {
+               case CORTEX_M_ISRMASK_AUTO:
+                       /* interrupts taken at resume, whether for step or run -> no mask */
+                       return cortex_m_set_maskints(target, false);
+
+               case CORTEX_M_ISRMASK_OFF:
+                       /* interrupts never masked */
+                       return cortex_m_set_maskints(target, false);
+
+               case CORTEX_M_ISRMASK_ON:
+                       /* interrupts always masked */
+                       return cortex_m_set_maskints(target, true);
+
+               case CORTEX_M_ISRMASK_STEPONLY:
+                       /* interrupts masked for single step only -> no mask */
+                       return cortex_m_set_maskints(target, false);
+       }
+       return ERROR_OK;
+}
+
+static int cortex_m_set_maskints_for_step(struct target *target)
+{
+       switch (target_to_cm(target)->isrmasking_mode) {
+               case CORTEX_M_ISRMASK_AUTO:
+                       /* the auto-interrupt should already be done -> mask */
+                       return cortex_m_set_maskints(target, true);
+
+               case CORTEX_M_ISRMASK_OFF:
+                       /* interrupts never masked */
+                       return cortex_m_set_maskints(target, false);
+
+               case CORTEX_M_ISRMASK_ON:
+                       /* interrupts always masked */
+                       return cortex_m_set_maskints(target, true);
+
+               case CORTEX_M_ISRMASK_STEPONLY:
+                       /* interrupts masked for single step only -> mask */
+                       return cortex_m_set_maskints(target, true);
+       }
+       return ERROR_OK;
+}
+
 static int cortex_m_clear_halt(struct target *target)
 {
        struct cortex_m_common *cortex_m = target_to_cm(target);
@@ -165,7 +242,7 @@ static int cortex_m_single_step_core(struct target *target)
        struct armv7m_common *armv7m = &cortex_m->armv7m;
        int retval;
 
-       /* Mask interrupts before clearing halt, if done already.  This avoids
+       /* Mask interrupts before clearing halt, if not done already.  This avoids
         * Erratum 377497 (fixed in r1p0) where setting MASKINTS while clearing
         * HALT can put the core into an unknown state.
         */
@@ -237,8 +314,8 @@ static int cortex_m_endreset_event(struct target *target)
                        return retval;
        }
 
-       /* clear any interrupt masking */
-       cortex_m_write_debug_halt_mask(target, 0, C_MASKINTS);
+       /* Restore proper interrupt masking setting for running CPU. */
+       cortex_m_set_maskints_for_run(target);
 
        /* Enable features controlled by ITM and DWT blocks, and catch only
         * the vectors we were told to pay attention to.
@@ -252,7 +329,7 @@ static int cortex_m_endreset_event(struct target *target)
                return retval;
 
        /* Paranoia: evidently some (early?) chips don't preserve all the
-        * debug state (including FBP, DWT, etc) across reset...
+        * debug state (including FPB, DWT, etc) across reset...
         */
 
        /* Enable FPB */
@@ -262,7 +339,7 @@ static int cortex_m_endreset_event(struct target *target)
                return retval;
        }
 
-       cortex_m->fpb_enabled = 1;
+       cortex_m->fpb_enabled = true;
 
        /* Restore FPB registers */
        for (i = 0; i < cortex_m->fp_num_code + cortex_m->fp_num_lit; i++) {
@@ -315,7 +392,9 @@ static int cortex_m_examine_debug_reason(struct target *target)
                        target->debug_reason = DBG_REASON_WATCHPOINT;
                else if (cortex_m->nvic_dfsr & DFSR_VCATCH)
                        target->debug_reason = DBG_REASON_BREAKPOINT;
-               else    /* EXTERNAL, HALTED */
+               else if (cortex_m->nvic_dfsr & DFSR_EXTERNAL)
+                       target->debug_reason = DBG_REASON_DBGRQ;
+               else    /* HALTED */
                        target->debug_reason = DBG_REASON_UNDEFINED;
        }
 
@@ -402,6 +481,10 @@ static int cortex_m_debug_entry(struct target *target)
 
        LOG_DEBUG(" ");
 
+       /* Do this really early to minimize the window where the MASKINTS erratum
+        * can pile up pending interrupts. */
+       cortex_m_set_maskints_for_halt(target);
+
        cortex_m_clear_halt(target);
        retval = mem_ap_read_atomic_u32(armv7m->debug_ap, DCB_DHCSR, &cortex_m->dcb_dhcsr);
        if (retval != ERROR_OK)
@@ -507,7 +590,10 @@ static int cortex_m_poll(struct target *target)
        }
 
        if (cortex_m->dcb_dhcsr & S_RESET_ST) {
-               target->state = TARGET_RESET;
+               if (target->state != TARGET_RESET) {
+                       target->state = TARGET_RESET;
+                       LOG_INFO("%s: external reset detected", target_name(target));
+               }
                return ERROR_OK;
        }
 
@@ -561,6 +647,17 @@ static int cortex_m_poll(struct target *target)
                }
        }
 
+       /* Check that target is truly halted, since the target could be resumed externally */
+       if ((prev_target_state == TARGET_HALTED) && !(cortex_m->dcb_dhcsr & S_HALT)) {
+               /* registers are now invalid */
+               register_cache_invalidate(armv7m->arm.core_cache);
+
+               target->state = TARGET_RUNNING;
+               LOG_WARNING("%s: external resume detected", target_name(target));
+               target_call_event_callbacks(target, TARGET_EVENT_RESUMED);
+               retval = ERROR_OK;
+       }
+
        /* Did we detect a failure condition that we cleared? */
        if (detected_failure != ERROR_OK)
                retval = detected_failure;
@@ -597,6 +694,10 @@ static int cortex_m_halt(struct target *target)
        /* Write to Debug Halting Control and Status Register */
        cortex_m_write_debug_halt_mask(target, C_HALT, 0);
 
+       /* Do this really early to minimize the window where the MASKINTS erratum
+        * can pile up pending interrupts. */
+       cortex_m_set_maskints_for_halt(target);
+
        target->debug_reason = DBG_REASON_DBGRQ;
 
        return ERROR_OK;
@@ -609,11 +710,16 @@ static int cortex_m_soft_reset_halt(struct target *target)
        uint32_t dcb_dhcsr = 0;
        int retval, timeout = 0;
 
-       /* soft_reset_halt is deprecated on cortex_m as the same functionality
-        * can be obtained by using 'reset halt' and 'cortex_m reset_config vectreset'
-        * As this reset only used VC_CORERESET it would only ever reset the cortex_m
+       /* on single cortex_m MCU soft_reset_halt should be avoided as same functionality
+        * can be obtained by using 'reset halt' and 'cortex_m reset_config vectreset'.
+        * As this reset only uses VC_CORERESET it would only ever reset the cortex_m
         * core, not the peripherals */
-       LOG_WARNING("soft_reset_halt is deprecated, please use 'reset halt' instead.");
+       LOG_DEBUG("soft_reset_halt is discouraged, please use 'reset halt' instead.");
+
+       /* Set C_DEBUGEN */
+       retval = cortex_m_write_debug_halt_mask(target, 0, C_STEP | C_MASKINTS);
+       if (retval != ERROR_OK)
+               return retval;
 
        /* Enter debug state on reset; restore DEMCR in endreset_event() */
        retval = mem_ap_write_u32(armv7m->debug_ap, DCB_DEMCR,
@@ -750,6 +856,7 @@ static int cortex_m_resume(struct target *target, int current,
        }
 
        /* Restart core */
+       cortex_m_set_maskints_for_run(target);
        cortex_m_write_debug_halt_mask(target, 0, C_HALT);
 
        target->debug_reason = DBG_REASON_NOTHALTED;
@@ -812,10 +919,12 @@ static int cortex_m_step(struct target *target, int current,
         * a normal step, otherwise we have to manually step over the bkpt
         * instruction - as such simulate a step */
        if (bkpt_inst_found == false) {
-               /* Automatic ISR masking mode off: Just step over the next instruction */
-               if ((cortex_m->isrmasking_mode != CORTEX_M_ISRMASK_AUTO))
+               if (cortex_m->isrmasking_mode != CORTEX_M_ISRMASK_AUTO) {
+                       /* Automatic ISR masking mode off: Just step over the next
+                        * instruction, with interrupts on or off as appropriate. */
+                       cortex_m_set_maskints_for_step(target);
                        cortex_m_write_debug_halt_mask(target, C_STEP, C_HALT);
-               else {
+               else {
                        /* Process interrupts during stepping in a way they don't interfere
                         * debugging.
                         *
@@ -854,25 +963,38 @@ static int cortex_m_step(struct target *target, int current,
                                LOG_DEBUG("Stepping over next instruction with interrupts disabled");
                                cortex_m_write_debug_halt_mask(target, C_HALT | C_MASKINTS, 0);
                                cortex_m_write_debug_halt_mask(target, C_STEP, C_HALT);
-                               /* Re-enable interrupts */
-                               cortex_m_write_debug_halt_mask(target, C_HALT, C_MASKINTS);
+                               /* Re-enable interrupts if appropriate */
+                               cortex_m_write_debug_halt_mask(target, C_HALT, 0);
+                               cortex_m_set_maskints_for_halt(target);
                        }
                        else {
 
                                /* Set a temporary break point */
-                               if (breakpoint)
+                               if (breakpoint) {
                                        retval = cortex_m_set_breakpoint(target, breakpoint);
-                               else
-                                       retval = breakpoint_add(target, pc_value, 2, BKPT_HARD);
+                               } else {
+                                       enum breakpoint_type type = BKPT_HARD;
+                                       if (cortex_m->fp_rev == 0 && pc_value > 0x1FFFFFFF) {
+                                               /* FPB rev.1 cannot handle such addr, try BKPT instr */
+                                               type = BKPT_SOFT;
+                                       }
+                                       retval = breakpoint_add(target, pc_value, 2, type);
+                               }
+
                                bool tmp_bp_set = (retval == ERROR_OK);
 
                                /* No more breakpoints left, just do a step */
-                               if (!tmp_bp_set)
+                               if (!tmp_bp_set) {
+                                       cortex_m_set_maskints_for_step(target);
                                        cortex_m_write_debug_halt_mask(target, C_STEP, C_HALT);
-                               else {
+                                       /* Re-enable interrupts if appropriate */
+                                       cortex_m_write_debug_halt_mask(target, C_HALT, 0);
+                                       cortex_m_set_maskints_for_halt(target);
+                               } else {
                                        /* Start the core */
                                        LOG_DEBUG("Starting core to serve pending interrupts");
                                        int64_t t_start = timeval_ms();
+                                       cortex_m_set_maskints_for_run(target);
                                        cortex_m_write_debug_halt_mask(target, 0, C_HALT | C_STEP);
 
                                        /* Wait for pending handlers to complete or timeout */
@@ -900,12 +1022,14 @@ static int cortex_m_step(struct target *target, int current,
                                                        "leaving target running");
                                        } else {
                                                /* Step over next instruction with interrupts disabled */
+                                               cortex_m_set_maskints_for_step(target);
                                                cortex_m_write_debug_halt_mask(target,
                                                        C_HALT | C_MASKINTS,
                                                        0);
                                                cortex_m_write_debug_halt_mask(target, C_STEP, C_HALT);
-                                               /* Re-enable interrupts */
-                                               cortex_m_write_debug_halt_mask(target, C_HALT, C_MASKINTS);
+                                               /* Re-enable interrupts if appropriate */
+                                               cortex_m_write_debug_halt_mask(target, C_HALT, 0);
+                                               cortex_m_set_maskints_for_halt(target);
                                        }
                                }
                        }
@@ -1007,8 +1131,7 @@ static int cortex_m_assert_reset(struct target *target)
 
        if (!target->reset_halt) {
                /* Set/Clear C_MASKINTS in a separate operation */
-               if (cortex_m->dcb_dhcsr & C_MASKINTS)
-                       cortex_m_write_debug_halt_mask(target, 0, C_MASKINTS);
+               cortex_m_set_maskints_for_run(target);
 
                /* clear any debug flags before resuming */
                cortex_m_clear_halt(target);
@@ -1038,10 +1161,18 @@ static int cortex_m_assert_reset(struct target *target)
                retval = ERROR_OK;
        } else {
                /* Use a standard Cortex-M3 software reset mechanism.
-                * We default to using VECRESET as it is supported on all current cores.
+                * We default to using VECRESET as it is supported on all current cores
+                * (except Cortex-M0, M0+ and M1 which support SYSRESETREQ only!)
                 * This has the disadvantage of not resetting the peripherals, so a
                 * reset-init event handler is needed to perform any peripheral resets.
                 */
+               if (!cortex_m->vectreset_supported
+                               && reset_config == CORTEX_M_RESET_VECTRESET) {
+                       reset_config = CORTEX_M_RESET_SYSRESETREQ;
+                       LOG_WARNING("VECTRESET is not supported on this Cortex-M core, using SYSRESETREQ instead.");
+                       LOG_WARNING("Set 'cortex_m reset_config sysresetreq'.");
+               }
+
                LOG_DEBUG("Using Cortex-M %s", (reset_config == CORTEX_M_RESET_SYSRESETREQ)
                        ? "SYSRESETREQ" : "VECTRESET");
 
@@ -1072,7 +1203,7 @@ static int cortex_m_assert_reset(struct target *target)
        }
 
        target->state = TARGET_RESET;
-       jtag_add_sleep(50000);
+       jtag_sleep(50000);
 
        register_cache_invalidate(cortex_m->armv7m.arm.core_cache);
 
@@ -1132,7 +1263,7 @@ int cortex_m_set_breakpoint(struct target *target, struct breakpoint *breakpoint
                        fp_num++;
                if (fp_num >= cortex_m->fp_num_code) {
                        LOG_ERROR("Can not find free FPB Comparator!");
-                       return ERROR_FAIL;
+                       return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
                }
                breakpoint->set = fp_num + 1;
                fpcr_value = breakpoint->address | 1;
@@ -1148,7 +1279,7 @@ int cortex_m_set_breakpoint(struct target *target, struct breakpoint *breakpoint
                        LOG_ERROR("Unhandled Cortex-M Flash Patch Breakpoint architecture revision");
                        return ERROR_FAIL;
                }
-               comparator_list[fp_num].used = 1;
+               comparator_list[fp_num].used = true;
                comparator_list[fp_num].fpcr_value = fpcr_value;
                target_write_u32(target, comparator_list[fp_num].fpcr_address,
                        comparator_list[fp_num].fpcr_value);
@@ -1163,7 +1294,7 @@ int cortex_m_set_breakpoint(struct target *target, struct breakpoint *breakpoint
                                return retval;
                        }
 
-                       cortex_m->fpb_enabled = 1;
+                       cortex_m->fpb_enabled = true;
                }
        } else if (breakpoint->type == BKPT_SOFT) {
                uint8_t code[4];
@@ -1222,23 +1353,17 @@ int cortex_m_unset_breakpoint(struct target *target, struct breakpoint *breakpoi
                        LOG_DEBUG("Invalid FP Comparator number in breakpoint");
                        return ERROR_OK;
                }
-               comparator_list[fp_num].used = 0;
+               comparator_list[fp_num].used = false;
                comparator_list[fp_num].fpcr_value = 0;
                target_write_u32(target, comparator_list[fp_num].fpcr_address,
                        comparator_list[fp_num].fpcr_value);
        } else {
                /* restore original instruction (kept in target endianness) */
-               if (breakpoint->length == 4) {
-                       retval = target_write_memory(target, breakpoint->address & 0xFFFFFFFE, 4, 1,
+               retval = target_write_memory(target, breakpoint->address & 0xFFFFFFFE,
+                                       breakpoint->length, 1,
                                        breakpoint->orig_instr);
-                       if (retval != ERROR_OK)
-                               return retval;
-               } else {
-                       retval = target_write_memory(target, breakpoint->address & 0xFFFFFFFE, 2, 1,
-                                       breakpoint->orig_instr);
-                       if (retval != ERROR_OK)
-                               return retval;
-               }
+               if (retval != ERROR_OK)
+                       return retval;
        }
        breakpoint->set = false;
 
@@ -1247,13 +1372,6 @@ int cortex_m_unset_breakpoint(struct target *target, struct breakpoint *breakpoi
 
 int cortex_m_add_breakpoint(struct target *target, struct breakpoint *breakpoint)
 {
-       struct cortex_m_common *cortex_m = target_to_cm(target);
-
-       if ((breakpoint->type == BKPT_HARD) && (cortex_m->fp_code_available < 1)) {
-               LOG_INFO("no flash patch comparator unit available for hardware breakpoint");
-               return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
-       }
-
        if (breakpoint->length == 3) {
                LOG_DEBUG("Using a two byte breakpoint for 32bit Thumb-2 request");
                breakpoint->length = 2;
@@ -1264,46 +1382,22 @@ int cortex_m_add_breakpoint(struct target *target, struct breakpoint *breakpoint
                return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
        }
 
-       if (breakpoint->type == BKPT_HARD)
-               cortex_m->fp_code_available--;
-
        return cortex_m_set_breakpoint(target, breakpoint);
 }
 
 int cortex_m_remove_breakpoint(struct target *target, struct breakpoint *breakpoint)
 {
-       struct cortex_m_common *cortex_m = target_to_cm(target);
-
-       /* REVISIT why check? FBP can be updated with core running ... */
-       if (target->state != TARGET_HALTED) {
-               LOG_WARNING("target not halted");
-               return ERROR_TARGET_NOT_HALTED;
-       }
-
-       if (breakpoint->set)
-               cortex_m_unset_breakpoint(target, breakpoint);
-
-       if (breakpoint->type == BKPT_HARD)
-               cortex_m->fp_code_available++;
+       if (!breakpoint->set)
+               return ERROR_OK;
 
-       return ERROR_OK;
+       return cortex_m_unset_breakpoint(target, breakpoint);
 }
 
 int cortex_m_set_watchpoint(struct target *target, struct watchpoint *watchpoint)
 {
        int dwt_num = 0;
-       uint32_t mask, temp;
        struct cortex_m_common *cortex_m = target_to_cm(target);
 
-       /* watchpoint params were validated earlier */
-       mask = 0;
-       temp = watchpoint->length;
-       while (temp) {
-               temp >>= 1;
-               mask++;
-       }
-       mask--;
-
        /* REVISIT Don't fully trust these "not used" records ... users
         * may set up breakpoints by hand, e.g. dual-address data value
         * watchpoint using comparator #1; comparator #0 matching cycle
@@ -1319,18 +1413,29 @@ int cortex_m_set_watchpoint(struct target *target, struct watchpoint *watchpoint
                LOG_ERROR("Can not find free DWT Comparator");
                return ERROR_FAIL;
        }
-       comparator->used = 1;
+       comparator->used = true;
        watchpoint->set = dwt_num + 1;
 
        comparator->comp = watchpoint->address;
        target_write_u32(target, comparator->dwt_comparator_address + 0,
                comparator->comp);
 
-       comparator->mask = mask;
-       target_write_u32(target, comparator->dwt_comparator_address + 4,
-               comparator->mask);
+       if ((cortex_m->dwt_devarch & 0x1FFFFF) != DWT_DEVARCH_ARMV8M) {
+               uint32_t mask = 0, temp;
+
+               /* watchpoint params were validated earlier */
+               temp = watchpoint->length;
+               while (temp) {
+                       temp >>= 1;
+                       mask++;
+               }
+               mask--;
+
+               comparator->mask = mask;
+               target_write_u32(target, comparator->dwt_comparator_address + 4,
+                       comparator->mask);
 
-       switch (watchpoint->rw) {
+               switch (watchpoint->rw) {
                case WPT_READ:
                        comparator->function = 5;
                        break;
@@ -1340,7 +1445,26 @@ int cortex_m_set_watchpoint(struct target *target, struct watchpoint *watchpoint
                case WPT_ACCESS:
                        comparator->function = 7;
                        break;
+               }
+       } else {
+               uint32_t data_size = watchpoint->length >> 1;
+               comparator->mask = (watchpoint->length >> 1) | 1;
+
+               switch (watchpoint->rw) {
+               case WPT_ACCESS:
+                       comparator->function = 4;
+                       break;
+               case WPT_WRITE:
+                       comparator->function = 5;
+                       break;
+               case WPT_READ:
+                       comparator->function = 6;
+                       break;
+               }
+               comparator->function = comparator->function | (1 << 4) |
+                               (data_size << 10);
        }
+
        target_write_u32(target, comparator->dwt_comparator_address + 8,
                comparator->function);
 
@@ -1376,7 +1500,7 @@ int cortex_m_unset_watchpoint(struct target *target, struct watchpoint *watchpoi
        }
 
        comparator = cortex_m->dwt_comparator_list + dwt_num;
-       comparator->used = 0;
+       comparator->used = false;
        comparator->function = 0;
        target_write_u32(target, comparator->dwt_comparator_address + 8,
                comparator->function);
@@ -1856,7 +1980,7 @@ static void cortex_m_dwt_addreg(struct target *t, struct reg *r, const struct dw
 {
        struct dwt_reg_state *state;
 
-       state = calloc(1, sizeof *state);
+       state = calloc(1, sizeof(*state));
        if (!state)
                return;
        state->addr = d->addr;
@@ -1883,6 +2007,9 @@ void cortex_m_dwt_setup(struct cortex_m_common *cm, struct target *target)
                return;
        }
 
+       target_read_u32(target, DWT_DEVARCH, &cm->dwt_devarch);
+       LOG_DEBUG("DWT_DEVARCH: 0x%" PRIx32, cm->dwt_devarch);
+
        cm->dwt_num_comp = (dwtcr >> 28) & 0xF;
        cm->dwt_comp_available = cm->dwt_num_comp;
        cm->dwt_comparator_list = calloc(cm->dwt_num_comp,
@@ -1894,7 +2021,7 @@ fail0:
                return;
        }
 
-       cache = calloc(1, sizeof *cache);
+       cache = calloc(1, sizeof(*cache));
        if (!cache) {
 fail1:
                free(cm->dwt_comparator_list);
@@ -1902,7 +2029,7 @@ fail1:
        }
        cache->name = "Cortex-M DWT registers";
        cache->num_regs = 2 + cm->dwt_num_comp * 3;
-       cache->reg_list = calloc(cache->num_regs, sizeof *cache->reg_list);
+       cache->reg_list = calloc(cache->num_regs, sizeof(*cache->reg_list));
        if (!cache->reg_list) {
                free(cache);
                goto fail1;
@@ -1971,6 +2098,15 @@ static void cortex_m_dwt_free(struct target *target)
 #define MVFR1_DEFAULT_M7_SP 0x11000011
 #define MVFR1_DEFAULT_M7_DP 0x12000011
 
+static int cortex_m_find_mem_ap(struct adiv5_dap *swjdp,
+               struct adiv5_ap **debug_ap)
+{
+       if (dap_find_ap(swjdp, AP_TYPE_AHB3_AP, debug_ap) == ERROR_OK)
+               return ERROR_OK;
+
+       return dap_find_ap(swjdp, AP_TYPE_AHB5_AP, debug_ap);
+}
+
 int cortex_m_examine(struct target *target)
 {
        int retval;
@@ -1983,9 +2119,9 @@ int cortex_m_examine(struct target *target)
        /* stlink shares the examine handler but does not support
         * all its calls */
        if (!armv7m->stlink) {
-               if (cortex_m->apsel < 0) {
+               if (cortex_m->apsel == DP_APSEL_INVALID) {
                        /* Search for the MEM-AP */
-                       retval = dap_find_ap(swjdp, AP_TYPE_AHB_AP, &armv7m->debug_ap);
+                       retval = cortex_m_find_mem_ap(swjdp, &armv7m->debug_ap);
                        if (retval != ERROR_OK) {
                                LOG_ERROR("Could not find MEM-AP to control the core");
                                return retval;
@@ -2013,17 +2149,37 @@ int cortex_m_examine(struct target *target)
                /* Get CPU Type */
                i = (cpuid >> 4) & 0xf;
 
+               switch (cpuid & ARM_CPUID_PARTNO_MASK) {
+                       case CORTEX_M23_PARTNO:
+                               i = 23;
+                               break;
+
+                       case CORTEX_M33_PARTNO:
+                               i = 33;
+                               break;
+
+                       default:
+                               break;
+               }
+
+
                LOG_DEBUG("Cortex-M%d r%" PRId8 "p%" PRId8 " processor detected",
                                i, (uint8_t)((cpuid >> 20) & 0xf), (uint8_t)((cpuid >> 0) & 0xf));
+               cortex_m->maskints_erratum = false;
                if (i == 7) {
                        uint8_t rev, patch;
                        rev = (cpuid >> 20) & 0xf;
                        patch = (cpuid >> 0) & 0xf;
-                       if ((rev == 0) && (patch < 2))
-                               LOG_WARNING("Silicon bug: single stepping will enter pending exception handler!");
+                       if ((rev == 0) && (patch < 2)) {
+                               LOG_WARNING("Silicon bug: single stepping may enter pending exception handler!");
+                               cortex_m->maskints_erratum = true;
+                       }
                }
                LOG_DEBUG("cpuid: 0x%8.8" PRIx32 "", cpuid);
 
+               /* VECTRESET is not supported on Cortex-M0, M0+ and M1 */
+               cortex_m->vectreset_supported = i > 1;
+
                if (i == 4) {
                        target_read_u32(target, MVFR0, &mvfr0);
                        target_read_u32(target, MVFR1, &mvfr1);
@@ -2033,7 +2189,7 @@ int cortex_m_examine(struct target *target)
                                LOG_DEBUG("Cortex-M%d floating point feature FPv4_SP found", i);
                                armv7m->fp_feature = FPv4_SP;
                        }
-               } else if (i == 7) {
+               } else if (i == 7 || i == 33) {
                        target_read_u32(target, MVFR0, &mvfr0);
                        target_read_u32(target, MVFR1, &mvfr1);
 
@@ -2092,7 +2248,6 @@ int cortex_m_examine(struct target *target)
                /* bits [14:12] and [7:4] */
                cortex_m->fp_num_code = ((fpcr >> 8) & 0x70) | ((fpcr >> 4) & 0xF);
                cortex_m->fp_num_lit = (fpcr >> 8) & 0xF;
-               cortex_m->fp_code_available = cortex_m->fp_num_code;
                /* Detect flash patch revision, see RM DDI 0403E.b page C1-817.
                   Revision is zero base, fp_rev == 1 means Rev.2 ! */
                cortex_m->fp_rev = (fpcr >> 28) & 0xf;
@@ -2234,21 +2389,27 @@ static int cortex_m_init_arch_info(struct target *target,
        armv7m->load_core_reg_u32 = cortex_m_load_core_reg_u32;
        armv7m->store_core_reg_u32 = cortex_m_store_core_reg_u32;
 
-       target_register_timer_callback(cortex_m_handle_target_request, 1, 1, target);
+       target_register_timer_callback(cortex_m_handle_target_request, 1,
+               TARGET_TIMER_TYPE_PERIODIC, target);
 
        return ERROR_OK;
 }
 
 static int cortex_m_target_create(struct target *target, Jim_Interp *interp)
 {
-       struct cortex_m_common *cortex_m = calloc(1, sizeof(struct cortex_m_common));
-       cortex_m->common_magic = CORTEX_M_COMMON_MAGIC;
        struct adiv5_private_config *pc;
 
        pc = (struct adiv5_private_config *)target->private_config;
        if (adiv5_verify_config(pc) != ERROR_OK)
                return ERROR_FAIL;
 
+       struct cortex_m_common *cortex_m = calloc(1, sizeof(struct cortex_m_common));
+       if (cortex_m == NULL) {
+               LOG_ERROR("No memory creating target");
+               return ERROR_FAIL;
+       }
+
+       cortex_m->common_magic = CORTEX_M_COMMON_MAGIC;
        cortex_m->apsel = pc->ap_num;
 
        cortex_m_init_arch_info(target, cortex_m, pc->dap);
@@ -2258,11 +2419,11 @@ static int cortex_m_target_create(struct target *target, Jim_Interp *interp)
 
 /*--------------------------------------------------------------------------*/
 
-static int cortex_m_verify_pointer(struct command_context *cmd_ctx,
+static int cortex_m_verify_pointer(struct command_invocation *cmd,
        struct cortex_m_common *cm)
 {
        if (cm->common_magic != CORTEX_M_COMMON_MAGIC) {
-               command_print(cmd_ctx, "target is not a Cortex-M");
+               command_print(cmd, "target is not a Cortex-M");
                return ERROR_TARGET_INVALID;
        }
        return ERROR_OK;
@@ -2296,7 +2457,7 @@ COMMAND_HANDLER(handle_cortex_m_vector_catch_command)
                { "reset",      VC_CORERESET, },
        };
 
-       retval = cortex_m_verify_pointer(CMD_CTX, cortex_m);
+       retval = cortex_m_verify_pointer(CMD, cortex_m);
        if (retval != ERROR_OK)
                return retval;
 
@@ -2351,7 +2512,7 @@ write:
        }
 
        for (unsigned i = 0; i < ARRAY_SIZE(vec_ids); i++) {
-               command_print(CMD_CTX, "%9s: %s", vec_ids[i].name,
+               command_print(CMD, "%9s: %s", vec_ids[i].name,
                        (demcr & vec_ids[i].mask) ? "catch" : "ignore");
        }
 
@@ -2368,17 +2529,18 @@ COMMAND_HANDLER(handle_cortex_m_mask_interrupts_command)
                { .name = "auto", .value = CORTEX_M_ISRMASK_AUTO },
                { .name = "off", .value = CORTEX_M_ISRMASK_OFF },
                { .name = "on", .value = CORTEX_M_ISRMASK_ON },
+               { .name = "steponly", .value = CORTEX_M_ISRMASK_STEPONLY },
                { .name = NULL, .value = -1 },
        };
        const Jim_Nvp *n;
 
 
-       retval = cortex_m_verify_pointer(CMD_CTX, cortex_m);
+       retval = cortex_m_verify_pointer(CMD, cortex_m);
        if (retval != ERROR_OK)
                return retval;
 
        if (target->state != TARGET_HALTED) {
-               command_print(CMD_CTX, "target must be stopped for \"%s\" command", CMD_NAME);
+               command_print(CMD, "target must be stopped for \"%s\" command", CMD_NAME);
                return ERROR_OK;
        }
 
@@ -2387,16 +2549,11 @@ COMMAND_HANDLER(handle_cortex_m_mask_interrupts_command)
                if (n->name == NULL)
                        return ERROR_COMMAND_SYNTAX_ERROR;
                cortex_m->isrmasking_mode = n->value;
-
-
-               if (cortex_m->isrmasking_mode == CORTEX_M_ISRMASK_ON)
-                       cortex_m_write_debug_halt_mask(target, C_HALT | C_MASKINTS, 0);
-               else
-                       cortex_m_write_debug_halt_mask(target, C_HALT, C_MASKINTS);
+               cortex_m_set_maskints_for_halt(target);
        }
 
        n = Jim_Nvp_value2name_simple(nvp_maskisr_modes, cortex_m->isrmasking_mode);
-       command_print(CMD_CTX, "cortex_m interrupt mask %s", n->name);
+       command_print(CMD, "cortex_m interrupt mask %s", n->name);
 
        return ERROR_OK;
 }
@@ -2408,15 +2565,23 @@ COMMAND_HANDLER(handle_cortex_m_reset_config_command)
        int retval;
        char *reset_config;
 
-       retval = cortex_m_verify_pointer(CMD_CTX, cortex_m);
+       retval = cortex_m_verify_pointer(CMD, cortex_m);
        if (retval != ERROR_OK)
                return retval;
 
        if (CMD_ARGC > 0) {
                if (strcmp(*CMD_ARGV, "sysresetreq") == 0)
                        cortex_m->soft_reset_config = CORTEX_M_RESET_SYSRESETREQ;
-               else if (strcmp(*CMD_ARGV, "vectreset") == 0)
-                       cortex_m->soft_reset_config = CORTEX_M_RESET_VECTRESET;
+
+               else if (strcmp(*CMD_ARGV, "vectreset") == 0) {
+                       if (target_was_examined(target)
+                                       && !cortex_m->vectreset_supported)
+                               LOG_WARNING("VECTRESET is not supported on your Cortex-M core!");
+                       else
+                               cortex_m->soft_reset_config = CORTEX_M_RESET_VECTRESET;
+
+               } else
+                       return ERROR_COMMAND_SYNTAX_ERROR;
        }
 
        switch (cortex_m->soft_reset_config) {
@@ -2433,7 +2598,7 @@ COMMAND_HANDLER(handle_cortex_m_reset_config_command)
                        break;
        }
 
-       command_print(CMD_CTX, "cortex_m reset_config %s", reset_config);
+       command_print(CMD, "cortex_m reset_config %s", reset_config);
 
        return ERROR_OK;
 }
@@ -2444,7 +2609,7 @@ static const struct command_registration cortex_m_exec_command_handlers[] = {
                .handler = handle_cortex_m_mask_interrupts_command,
                .mode = COMMAND_EXEC,
                .help = "mask cortex_m interrupts",
-               .usage = "['auto'|'on'|'off']",
+               .usage = "['auto'|'on'|'off'|'steponly']",
        },
        {
                .name = "vector_catch",
@@ -2458,7 +2623,7 @@ static const struct command_registration cortex_m_exec_command_handlers[] = {
                .handler = handle_cortex_m_reset_config_command,
                .mode = COMMAND_ANY,
                .help = "configure software reset handling",
-               .usage = "['srst'|'sysresetreq'|'vectreset']",
+               .usage = "['sysresetreq'|'vectreset']",
        },
        COMMAND_REGISTRATION_DONE
 };
@@ -2496,6 +2661,7 @@ struct target_type cortexm_target = {
        .deassert_reset = cortex_m_deassert_reset,
        .soft_reset_halt = cortex_m_soft_reset_halt,
 
+       .get_gdb_arch = arm_get_gdb_arch,
        .get_gdb_reg_list = armv7m_get_gdb_reg_list,
 
        .read_memory = cortex_m_read_memory,