]> git.sur5r.net Git - openocd/blobdiff - src/target/cortex_m3.c
cortex_m3: add BKPT_TYPE_BY_ADDR define
[openocd] / src / target / cortex_m3.c
index 6079b9ebdeb0f6a920eb9ee2f582512874efd363..9c3d2d9d691ffa9b13f1fd9bbbaa4518f5cc43c5 100644 (file)
  *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
  *                                                                         *
  *                                                                         *
- *   Cortex-M3(tm) TRM, ARM DDI 0337C                                      *
+ *   Cortex-M3(tm) TRM, ARM DDI 0337E (r1p1) and 0337G (r2p0)              *
  *                                                                         *
  ***************************************************************************/
 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif
 
+#include "breakpoints.h"
 #include "cortex_m3.h"
 #include "target_request.h"
 #include "target_type.h"
+#include "arm_disassembler.h"
+#include "register.h"
+#include "arm_opcodes.h"
+#include "arm_semihosting.h"
+
+/* 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
+ * any longer.
+ */
+
+/**
+ * Returns the type of a break point required by address location
+ */
+#define BKPT_TYPE_BY_ADDR(addr) ((addr) < 0x20000000 ? BKPT_HARD : BKPT_SOFT)
 
 
-/* cli handling */
-int cortex_m3_register_commands(struct command_context_s *cmd_ctx);
-int handle_cortex_m3_mask_interrupts_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
-
 /* forward declarations */
-void cortex_m3_enable_breakpoints(struct target_s *target);
-void cortex_m3_enable_watchpoints(struct target_s *target);
-int cortex_m3_target_create(struct target_s *target, Jim_Interp *interp);
-int cortex_m3_init_target(struct command_context_s *cmd_ctx, struct target_s *target);
-int cortex_m3_quit(void);
-int cortex_m3_load_core_reg_u32(target_t *target, enum armv7m_regtype type, uint32_t num, uint32_t *value);
-int cortex_m3_store_core_reg_u32(target_t *target, enum armv7m_regtype type, uint32_t num, uint32_t value);
-int cortex_m3_target_request_data(target_t *target, uint32_t size, uint8_t *buffer);
-int cortex_m3_examine(struct target_s *target);
-
-#ifdef ARMV7_GDB_HACKS
-extern uint8_t armv7m_gdb_dummy_cpsr_value[];
-extern reg_t armv7m_gdb_dummy_cpsr_reg;
-#endif
-
-target_type_t cortexm3_target =
-{
-       .name = "cortex_m3",
-
-       .poll = cortex_m3_poll,
-       .arch_state = armv7m_arch_state,
-
-       .target_request_data = cortex_m3_target_request_data,
-
-       .halt = cortex_m3_halt,
-       .resume = cortex_m3_resume,
-       .step = cortex_m3_step,
-
-       .assert_reset = cortex_m3_assert_reset,
-       .deassert_reset = cortex_m3_deassert_reset,
-       .soft_reset_halt = cortex_m3_soft_reset_halt,
-
-       .get_gdb_reg_list = armv7m_get_gdb_reg_list,
-
-       .read_memory = cortex_m3_read_memory,
-       .write_memory = cortex_m3_write_memory,
-       .bulk_write_memory = cortex_m3_bulk_write_memory,
-       .checksum_memory = armv7m_checksum_memory,
-       .blank_check_memory = armv7m_blank_check_memory,
-
-       .run_algorithm = armv7m_run_algorithm,
-
-       .add_breakpoint = cortex_m3_add_breakpoint,
-       .remove_breakpoint = cortex_m3_remove_breakpoint,
-       .add_watchpoint = cortex_m3_add_watchpoint,
-       .remove_watchpoint = cortex_m3_remove_watchpoint,
-
-       .register_commands = cortex_m3_register_commands,
-       .target_create = cortex_m3_target_create,
-       .init_target = cortex_m3_init_target,
-       .examine = cortex_m3_examine,
-       .quit = cortex_m3_quit
-};
-
-int cortexm3_dap_read_coreregister_u32(swjdp_common_t *swjdp, uint32_t *value, int regnum)
+static int cortex_m3_set_breakpoint(struct target *target, struct breakpoint *breakpoint);
+static int cortex_m3_unset_breakpoint(struct target *target, struct breakpoint *breakpoint);
+static void cortex_m3_enable_watchpoints(struct target *target);
+static int cortex_m3_store_core_reg_u32(struct target *target,
+               enum armv7m_regtype type, uint32_t num, uint32_t value);
+
+static int cortexm3_dap_read_coreregister_u32(struct adiv5_dap *swjdp,
+               uint32_t *value, int regnum)
 {
        int retval;
        uint32_t dcrdr;
 
        /* because the DCB_DCRDR is used for the emulated dcc channel
-        * we gave to save/restore the DCB_DCRDR when used */
-
-       mem_ap_read_u32(swjdp, DCB_DCRDR, &dcrdr);
+        * we have to save/restore the DCB_DCRDR when used */
 
-       swjdp->trans_mode = TRANS_MODE_COMPOSITE;
+       retval = mem_ap_read_u32(swjdp, DCB_DCRDR, &dcrdr);
+       if (retval != ERROR_OK)
+               return retval;
 
        /* mem_ap_write_u32(swjdp, DCB_DCRSR, regnum); */
-       dap_setup_accessport(swjdp, CSW_32BIT | CSW_ADDRINC_OFF, DCB_DCRSR & 0xFFFFFFF0);
-       dap_ap_write_reg_u32(swjdp, AP_REG_BD0 | (DCB_DCRSR & 0xC), regnum );
+       retval = dap_setup_accessport(swjdp, CSW_32BIT | CSW_ADDRINC_OFF, DCB_DCRSR & 0xFFFFFFF0);
+       if (retval != ERROR_OK)
+               return retval;
+       retval = dap_queue_ap_write(swjdp, AP_REG_BD0 | (DCB_DCRSR & 0xC), regnum);
+       if (retval != ERROR_OK)
+               return retval;
 
        /* mem_ap_read_u32(swjdp, DCB_DCRDR, value); */
-       dap_setup_accessport(swjdp, CSW_32BIT | CSW_ADDRINC_OFF, DCB_DCRDR & 0xFFFFFFF0);
-       dap_ap_read_reg_u32(swjdp, AP_REG_BD0 | (DCB_DCRDR & 0xC), value );
+       retval = dap_setup_accessport(swjdp, CSW_32BIT | CSW_ADDRINC_OFF, DCB_DCRDR & 0xFFFFFFF0);
+       if (retval != ERROR_OK)
+               return retval;
+       retval = dap_queue_ap_read(swjdp, AP_REG_BD0 | (DCB_DCRDR & 0xC), value);
+       if (retval != ERROR_OK)
+               return retval;
+
+       retval = dap_run(swjdp);
+       if (retval != ERROR_OK)
+               return retval;
+
+       /* restore DCB_DCRDR - this needs to be in a seperate
+        * transaction otherwise the emulated DCC channel breaks */
+       if (retval == ERROR_OK)
+               retval = mem_ap_write_atomic_u32(swjdp, DCB_DCRDR, dcrdr);
 
-       mem_ap_write_u32(swjdp, DCB_DCRDR, dcrdr);
-       retval = swjdp_transaction_endcheck(swjdp);
        return retval;
 }
 
-int cortexm3_dap_write_coreregister_u32(swjdp_common_t *swjdp, uint32_t value, int regnum)
+static int cortexm3_dap_write_coreregister_u32(struct adiv5_dap *swjdp,
+               uint32_t value, int regnum)
 {
        int retval;
        uint32_t dcrdr;
 
        /* because the DCB_DCRDR is used for the emulated dcc channel
-        * we gave to save/restore the DCB_DCRDR when used */
+        * we have to save/restore the DCB_DCRDR when used */
 
-       mem_ap_read_u32(swjdp, DCB_DCRDR, &dcrdr);
-
-       swjdp->trans_mode = TRANS_MODE_COMPOSITE;
+       retval = mem_ap_read_u32(swjdp, DCB_DCRDR, &dcrdr);
+       if (retval != ERROR_OK)
+               return retval;
 
        /* mem_ap_write_u32(swjdp, DCB_DCRDR, core_regs[i]); */
-       dap_setup_accessport(swjdp, CSW_32BIT | CSW_ADDRINC_OFF, DCB_DCRDR & 0xFFFFFFF0);
-       dap_ap_write_reg_u32(swjdp, AP_REG_BD0 | (DCB_DCRDR & 0xC), value );
+       retval = dap_setup_accessport(swjdp, CSW_32BIT | CSW_ADDRINC_OFF, DCB_DCRDR & 0xFFFFFFF0);
+       if (retval != ERROR_OK)
+               return retval;
+       retval = dap_queue_ap_write(swjdp, AP_REG_BD0 | (DCB_DCRDR & 0xC), value);
+       // XXX check retval
+
+       /* mem_ap_write_u32(swjdp, DCB_DCRSR, i | DCRSR_WnR); */
+       retval = dap_setup_accessport(swjdp, CSW_32BIT | CSW_ADDRINC_OFF, DCB_DCRSR & 0xFFFFFFF0);
+       if (retval != ERROR_OK)
+               return retval;
+       retval = dap_queue_ap_write(swjdp, AP_REG_BD0 | (DCB_DCRSR & 0xC), regnum | DCRSR_WnR);
+       // XXX check retval
+
+       retval = dap_run(swjdp);
 
-       /* mem_ap_write_u32(swjdp, DCB_DCRSR, i | DCRSR_WnR     ); */
-       dap_setup_accessport(swjdp, CSW_32BIT | CSW_ADDRINC_OFF, DCB_DCRSR & 0xFFFFFFF0);
-       dap_ap_write_reg_u32(swjdp, AP_REG_BD0 | (DCB_DCRSR & 0xC), regnum | DCRSR_WnR );
+       /* restore DCB_DCRDR - this needs to be in a seperate
+        * transaction otherwise the emulated DCC channel breaks */
+       if (retval == ERROR_OK)
+               retval = mem_ap_write_atomic_u32(swjdp, DCB_DCRDR, dcrdr);
 
-       mem_ap_write_u32(swjdp, DCB_DCRDR, dcrdr);
-       retval = swjdp_transaction_endcheck(swjdp);
        return retval;
 }
 
-
-int cortex_m3_write_debug_halt_mask(target_t *target, uint32_t mask_on, uint32_t mask_off)
+static int cortex_m3_write_debug_halt_mask(struct target *target,
+               uint32_t mask_on, uint32_t mask_off)
 {
-       /* get pointers to arch-specific information */
-       armv7m_common_t *armv7m = target->arch_info;
-       cortex_m3_common_t *cortex_m3 = armv7m->arch_info;
-       swjdp_common_t *swjdp = &armv7m->swjdp_info;
+       struct cortex_m3_common *cortex_m3 = target_to_cm3(target);
+       struct adiv5_dap *swjdp = &cortex_m3->armv7m.dap;
 
        /* mask off status bits */
        cortex_m3->dcb_dhcsr &= ~((0xFFFF << 16) | mask_off);
@@ -161,40 +156,54 @@ int cortex_m3_write_debug_halt_mask(target_t *target, uint32_t mask_on, uint32_t
        return mem_ap_write_atomic_u32(swjdp, DCB_DHCSR, cortex_m3->dcb_dhcsr);
 }
 
-int cortex_m3_clear_halt(target_t *target)
+static int cortex_m3_clear_halt(struct target *target)
 {
-       /* get pointers to arch-specific information */
-       armv7m_common_t *armv7m = target->arch_info;
-       cortex_m3_common_t *cortex_m3 = armv7m->arch_info;
-       swjdp_common_t *swjdp = &armv7m->swjdp_info;
+       struct cortex_m3_common *cortex_m3 = target_to_cm3(target);
+       struct adiv5_dap *swjdp = &cortex_m3->armv7m.dap;
+       int retval;
 
        /* clear step if any */
        cortex_m3_write_debug_halt_mask(target, C_HALT, C_STEP);
 
        /* Read Debug Fault Status Register */
-       mem_ap_read_atomic_u32(swjdp, NVIC_DFSR, &cortex_m3->nvic_dfsr);
-       /* Write Debug Fault Status Register to enable processing to resume ?? Try with and without this !! */
-       mem_ap_write_atomic_u32(swjdp, NVIC_DFSR, cortex_m3->nvic_dfsr);
+       retval = mem_ap_read_atomic_u32(swjdp, NVIC_DFSR, &cortex_m3->nvic_dfsr);
+       if (retval != ERROR_OK)
+               return retval;
+
+       /* Clear Debug Fault Status */
+       retval = mem_ap_write_atomic_u32(swjdp, NVIC_DFSR, cortex_m3->nvic_dfsr);
+       if (retval != ERROR_OK)
+               return retval;
        LOG_DEBUG(" NVIC_DFSR 0x%" PRIx32 "", cortex_m3->nvic_dfsr);
 
        return ERROR_OK;
 }
 
-int cortex_m3_single_step_core(target_t *target)
+static int cortex_m3_single_step_core(struct target *target)
 {
-       /* get pointers to arch-specific information */
-       armv7m_common_t *armv7m = target->arch_info;
-       cortex_m3_common_t *cortex_m3 = armv7m->arch_info;
-       swjdp_common_t *swjdp = &armv7m->swjdp_info;
+       struct cortex_m3_common *cortex_m3 = target_to_cm3(target);
+       struct adiv5_dap *swjdp = &cortex_m3->armv7m.dap;
        uint32_t dhcsr_save;
+       int retval;
 
        /* backup dhcsr reg */
        dhcsr_save = cortex_m3->dcb_dhcsr;
 
-       /* mask interrupts if not done already */
+       /* Mask interrupts before clearing halt, if done already.  This avoids
+        * Erratum 377497 (fixed in r1p0) where setting MASKINTS while clearing
+        * HALT can put the core into an unknown state.
+        */
        if (!(cortex_m3->dcb_dhcsr & C_MASKINTS))
-               mem_ap_write_atomic_u32(swjdp, DCB_DHCSR, DBGKEY | C_MASKINTS | C_HALT | C_DEBUGEN);
-       mem_ap_write_atomic_u32(swjdp, DCB_DHCSR, DBGKEY | C_MASKINTS | C_STEP | C_DEBUGEN);
+       {
+               retval = mem_ap_write_atomic_u32(swjdp, DCB_DHCSR,
+                               DBGKEY | C_MASKINTS | C_HALT | C_DEBUGEN);
+               if (retval != ERROR_OK)
+                       return retval;
+       }
+       retval = mem_ap_write_atomic_u32(swjdp, DCB_DHCSR,
+                               DBGKEY | C_MASKINTS | C_STEP | C_DEBUGEN);
+       if (retval != ERROR_OK)
+               return retval;
        LOG_DEBUG(" ");
 
        /* restore dhcsr reg */
@@ -204,101 +213,103 @@ int cortex_m3_single_step_core(target_t *target)
        return ERROR_OK;
 }
 
-int cortex_m3_exec_opcode(target_t *target,uint32_t opcode, int len /* MODE, r0_invalue, &r0_outvalue */ )
-{
-       /* get pointers to arch-specific information */
-       armv7m_common_t *armv7m = target->arch_info;
-       swjdp_common_t *swjdp = &armv7m->swjdp_info;
-       uint32_t savedram;
-       int retvalue;
-
-       mem_ap_read_u32(swjdp, 0x20000000, &savedram);
-       mem_ap_write_u32(swjdp, 0x20000000, opcode);
-       cortexm3_dap_write_coreregister_u32(swjdp, 0x20000000, 15);
-       cortex_m3_single_step_core(target);
-       armv7m->core_cache->reg_list[15].dirty = armv7m->core_cache->reg_list[15].valid;
-       retvalue = mem_ap_write_atomic_u32(swjdp, 0x20000000, savedram);
-
-       return retvalue;
-}
-
-#if 0
-/* Enable interrupts */
-int cortex_m3_cpsie(target_t *target, uint32_t IF)
-{
-       return cortex_m3_exec_opcode(target, ARMV7M_T_CPSIE(IF), 2);
-}
-
-/* Disable interrupts */
-int cortex_m3_cpsid(target_t *target, uint32_t IF)
-{
-       return cortex_m3_exec_opcode(target, ARMV7M_T_CPSID(IF), 2);
-}
-#endif
-
-int cortex_m3_endreset_event(target_t *target)
+static int cortex_m3_endreset_event(struct target *target)
 {
        int i;
+       int retval;
        uint32_t dcb_demcr;
-
-       /* get pointers to arch-specific information */
-       armv7m_common_t *armv7m = target->arch_info;
-       cortex_m3_common_t *cortex_m3 = armv7m->arch_info;
-       swjdp_common_t *swjdp = &armv7m->swjdp_info;
-       cortex_m3_fp_comparator_t *fp_list = cortex_m3->fp_comparator_list;
-       cortex_m3_dwt_comparator_t *dwt_list = cortex_m3->dwt_comparator_list;
-
-       mem_ap_read_atomic_u32(swjdp, DCB_DEMCR, &dcb_demcr);
+       struct cortex_m3_common *cortex_m3 = target_to_cm3(target);
+       struct armv7m_common *armv7m = &cortex_m3->armv7m;
+       struct adiv5_dap *swjdp = &cortex_m3->armv7m.dap;
+       struct cortex_m3_fp_comparator *fp_list = cortex_m3->fp_comparator_list;
+       struct cortex_m3_dwt_comparator *dwt_list = cortex_m3->dwt_comparator_list;
+
+       /* REVISIT The four debug monitor bits are currently ignored... */
+       retval = mem_ap_read_atomic_u32(swjdp, DCB_DEMCR, &dcb_demcr);
+       if (retval != ERROR_OK)
+               return retval;
        LOG_DEBUG("DCB_DEMCR = 0x%8.8" PRIx32 "",dcb_demcr);
 
-       /* this regsiter is used for emulated dcc channel */
-       mem_ap_write_u32(swjdp, DCB_DCRDR, 0);
+       /* this register is used for emulated dcc channel */
+       retval = mem_ap_write_u32(swjdp, DCB_DCRDR, 0);
+       if (retval != ERROR_OK)
+               return retval;
 
        /* Enable debug requests */
-       mem_ap_read_atomic_u32(swjdp, DCB_DHCSR, &cortex_m3->dcb_dhcsr);
+       retval = mem_ap_read_atomic_u32(swjdp, DCB_DHCSR, &cortex_m3->dcb_dhcsr);
+       if (retval != ERROR_OK)
+               return retval;
        if (!(cortex_m3->dcb_dhcsr & C_DEBUGEN))
-               mem_ap_write_u32(swjdp, DCB_DHCSR, DBGKEY | C_DEBUGEN);
+       {
+               retval = mem_ap_write_u32(swjdp, DCB_DHCSR, DBGKEY | C_DEBUGEN);
+               if (retval != ERROR_OK)
+                       return retval;
+       }
 
        /* clear any interrupt masking */
        cortex_m3_write_debug_halt_mask(target, 0, C_MASKINTS);
 
-       /* Enable trace and dwt */
-       mem_ap_write_u32(swjdp, DCB_DEMCR, TRCENA | VC_HARDERR | VC_BUSERR);
-       /* Monitor bus faults */
-       mem_ap_write_u32(swjdp, NVIC_SHCSR, SHCSR_BUSFAULTENA);
+       /* Enable features controlled by ITM and DWT blocks, and catch only
+        * the vectors we were told to pay attention to.
+        *
+        * 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.
+        */
+       retval = mem_ap_write_u32(swjdp, DCB_DEMCR, TRCENA | armv7m->demcr);
+       if (retval != ERROR_OK)
+               return retval;
+
+       /* Paranoia: evidently some (early?) chips don't preserve all the
+        * debug state (including FBP, DWT, etc) across reset...
+        */
 
        /* Enable FPB */
-       target_write_u32(target, FP_CTRL, 3);
+       retval = target_write_u32(target, FP_CTRL, 3);
+       if (retval != ERROR_OK)
+               return retval;
+
        cortex_m3->fpb_enabled = 1;
 
        /* Restore FPB registers */
        for (i = 0; i < cortex_m3->fp_num_code + cortex_m3->fp_num_lit; i++)
        {
-               target_write_u32(target, fp_list[i].fpcr_address, fp_list[i].fpcr_value);
+               retval = target_write_u32(target, fp_list[i].fpcr_address, fp_list[i].fpcr_value);
+               if (retval != ERROR_OK)
+                       return retval;
        }
 
        /* Restore DWT registers */
        for (i = 0; i < cortex_m3->dwt_num_comp; i++)
        {
-               target_write_u32(target, dwt_list[i].dwt_comparator_address, dwt_list[i].comp);
-               target_write_u32(target, dwt_list[i].dwt_comparator_address | 0x4, dwt_list[i].mask);
-               target_write_u32(target, dwt_list[i].dwt_comparator_address | 0x8, dwt_list[i].function);
+               retval = target_write_u32(target, dwt_list[i].dwt_comparator_address + 0,
+                               dwt_list[i].comp);
+               if (retval != ERROR_OK)
+                       return retval;
+               retval = target_write_u32(target, dwt_list[i].dwt_comparator_address + 4,
+                               dwt_list[i].mask);
+               if (retval != ERROR_OK)
+                       return retval;
+               retval = target_write_u32(target, dwt_list[i].dwt_comparator_address + 8,
+                               dwt_list[i].function);
+               if (retval != ERROR_OK)
+                       return retval;
        }
-       swjdp_transaction_endcheck(swjdp);
+       retval = dap_run(swjdp);
+       if (retval != ERROR_OK)
+               return retval;
 
-       armv7m_invalidate_core_regs(target);
+       register_cache_invalidate(cortex_m3->armv7m.core_cache);
 
        /* make sure we have latest dhcsr flags */
-       mem_ap_read_atomic_u32(swjdp, DCB_DHCSR, &cortex_m3->dcb_dhcsr);
+       retval = mem_ap_read_atomic_u32(swjdp, DCB_DHCSR, &cortex_m3->dcb_dhcsr);
 
-       return ERROR_OK;
+       return retval;
 }
 
-int cortex_m3_examine_debug_reason(target_t *target)
+static int cortex_m3_examine_debug_reason(struct target *target)
 {
-       /* get pointers to arch-specific information */
-       armv7m_common_t *armv7m = target->arch_info;
-       cortex_m3_common_t *cortex_m3 = armv7m->arch_info;
+       struct cortex_m3_common *cortex_m3 = target_to_cm3(target);
 
        /* THIS IS NOT GOOD, TODO - better logic for detection of debug state reason */
        /* only check the debug reason if we don't know it already */
@@ -306,8 +317,6 @@ int cortex_m3_examine_debug_reason(target_t *target)
        if ((target->debug_reason != DBG_REASON_DBGRQ)
                && (target->debug_reason != DBG_REASON_SINGLESTEP))
        {
-               /*  INCOMPLETE */
-
                if (cortex_m3->nvic_dfsr & DFSR_BKPT)
                {
                        target->debug_reason = DBG_REASON_BREAKPOINT;
@@ -316,46 +325,67 @@ int cortex_m3_examine_debug_reason(target_t *target)
                }
                else if (cortex_m3->nvic_dfsr & DFSR_DWTTRAP)
                        target->debug_reason = DBG_REASON_WATCHPOINT;
+               else if (cortex_m3->nvic_dfsr & DFSR_VCATCH)
+                       target->debug_reason = DBG_REASON_BREAKPOINT;
+               else /* EXTERNAL, HALTED */
+                       target->debug_reason = DBG_REASON_UNDEFINED;
        }
 
        return ERROR_OK;
 }
 
-int cortex_m3_examine_exception_reason(target_t *target)
+static int cortex_m3_examine_exception_reason(struct target *target)
 {
        uint32_t shcsr, except_sr, cfsr = -1, except_ar = -1;
+       struct armv7m_common *armv7m = target_to_armv7m(target);
+       struct adiv5_dap *swjdp = &armv7m->dap;
+       int retval;
 
-       /* get pointers to arch-specific information */
-       armv7m_common_t *armv7m = target->arch_info;
-       swjdp_common_t *swjdp = &armv7m->swjdp_info;
-
-       mem_ap_read_u32(swjdp, NVIC_SHCSR, &shcsr);
+       retval = mem_ap_read_u32(swjdp, NVIC_SHCSR, &shcsr);
+       if (retval != ERROR_OK)
+               return retval;
        switch (armv7m->exception_number)
        {
                case 2: /* NMI */
                        break;
                case 3: /* Hard Fault */
-                       mem_ap_read_atomic_u32(swjdp, NVIC_HFSR, &except_sr);
+                       retval = mem_ap_read_atomic_u32(swjdp, NVIC_HFSR, &except_sr);
+                       if (retval != ERROR_OK)
+                               return retval;
                        if (except_sr & 0x40000000)
                        {
-                               mem_ap_read_u32(swjdp, NVIC_CFSR, &cfsr);
+                               retval = mem_ap_read_u32(swjdp, NVIC_CFSR, &cfsr);
+                               if (retval != ERROR_OK)
+                                       return retval;
                        }
                        break;
                case 4: /* Memory Management */
-                       mem_ap_read_u32(swjdp, NVIC_CFSR, &except_sr);
-                       mem_ap_read_u32(swjdp, NVIC_MMFAR, &except_ar);
+                       retval = mem_ap_read_u32(swjdp, NVIC_CFSR, &except_sr);
+                       if (retval != ERROR_OK)
+                               return retval;
+                       retval = mem_ap_read_u32(swjdp, NVIC_MMFAR, &except_ar);
+                       if (retval != ERROR_OK)
+                               return retval;
                        break;
                case 5: /* Bus Fault */
-                       mem_ap_read_u32(swjdp, NVIC_CFSR, &except_sr);
-                       mem_ap_read_u32(swjdp, NVIC_BFAR, &except_ar);
+                       retval = mem_ap_read_u32(swjdp, NVIC_CFSR, &except_sr);
+                       if (retval != ERROR_OK)
+                               return retval;
+                       retval = mem_ap_read_u32(swjdp, NVIC_BFAR, &except_ar);
+                       if (retval != ERROR_OK)
+                               return retval;
                        break;
                case 6: /* Usage Fault */
-                       mem_ap_read_u32(swjdp, NVIC_CFSR, &except_sr);
+                       retval = mem_ap_read_u32(swjdp, NVIC_CFSR, &except_sr);
+                       if (retval != ERROR_OK)
+                               return retval;
                        break;
                case 11:        /* SVCall */
                        break;
                case 12:        /* Debug Monitor */
-                       mem_ap_read_u32(swjdp, NVIC_DFSR, &except_sr);
+                       retval = mem_ap_read_u32(swjdp, NVIC_DFSR, &except_sr);
+                       if (retval != ERROR_OK)
+                               return retval;
                        break;
                case 14:        /* PendSV */
                        break;
@@ -365,74 +395,111 @@ int cortex_m3_examine_exception_reason(target_t *target)
                        except_sr = 0;
                        break;
        }
-       swjdp_transaction_endcheck(swjdp);
-       LOG_DEBUG("%s SHCSR 0x%" PRIx32 ", SR 0x%" PRIx32 ", CFSR 0x%" PRIx32 ", AR 0x%" PRIx32 "", armv7m_exception_string(armv7m->exception_number), \
-               shcsr, except_sr, cfsr, except_ar);
-       return ERROR_OK;
+       retval = dap_run(swjdp);
+       if (retval == ERROR_OK)
+               LOG_DEBUG("%s SHCSR 0x%" PRIx32 ", SR 0x%" PRIx32
+                       ", CFSR 0x%" PRIx32 ", AR 0x%" PRIx32,
+                       armv7m_exception_string(armv7m->exception_number),
+                       shcsr, except_sr, cfsr, except_ar);
+       return retval;
 }
 
-int cortex_m3_debug_entry(target_t *target)
+/* PSP is used in some thread modes */
+static const int armv7m_psp_reg_map[17] = {
+       ARMV7M_R0, ARMV7M_R1, ARMV7M_R2, ARMV7M_R3,
+       ARMV7M_R4, ARMV7M_R5, ARMV7M_R6, ARMV7M_R7,
+       ARMV7M_R8, ARMV7M_R9, ARMV7M_R10, ARMV7M_R11,
+       ARMV7M_R12, ARMV7M_PSP, ARMV7M_R14, ARMV7M_PC,
+       ARMV7M_xPSR,
+};
+
+/* MSP is used in handler and some thread modes */
+static const int armv7m_msp_reg_map[17] = {
+       ARMV7M_R0, ARMV7M_R1, ARMV7M_R2, ARMV7M_R3,
+       ARMV7M_R4, ARMV7M_R5, ARMV7M_R6, ARMV7M_R7,
+       ARMV7M_R8, ARMV7M_R9, ARMV7M_R10, ARMV7M_R11,
+       ARMV7M_R12, ARMV7M_MSP, ARMV7M_R14, ARMV7M_PC,
+       ARMV7M_xPSR,
+};
+
+static int cortex_m3_debug_entry(struct target *target)
 {
        int i;
        uint32_t xPSR;
        int retval;
-
-       /* get pointers to arch-specific information */
-       armv7m_common_t *armv7m = target->arch_info;
-       cortex_m3_common_t *cortex_m3 = armv7m->arch_info;
-       swjdp_common_t *swjdp = &armv7m->swjdp_info;
+       struct cortex_m3_common *cortex_m3 = target_to_cm3(target);
+       struct armv7m_common *armv7m = &cortex_m3->armv7m;
+       struct arm *arm = &armv7m->arm;
+       struct adiv5_dap *swjdp = &armv7m->dap;
+       struct reg *r;
 
        LOG_DEBUG(" ");
-       if (armv7m->pre_debug_entry)
-               armv7m->pre_debug_entry(target);
 
        cortex_m3_clear_halt(target);
-       mem_ap_read_atomic_u32(swjdp, DCB_DHCSR, &cortex_m3->dcb_dhcsr);
+       retval = mem_ap_read_atomic_u32(swjdp, DCB_DHCSR, &cortex_m3->dcb_dhcsr);
+       if (retval != ERROR_OK)
+               return retval;
 
        if ((retval = armv7m->examine_debug_reason(target)) != ERROR_OK)
                return retval;
 
        /* Examine target state and mode */
        /* First load register acessible through core debug port*/
-       for (i = 0; i < ARMV7M_PRIMASK; i++)
+       int num_regs = armv7m->core_cache->num_regs;
+
+       for (i = 0; i < num_regs; i++)
        {
                if (!armv7m->core_cache->reg_list[i].valid)
                        armv7m->read_core_reg(target, i);
        }
 
-       xPSR = buf_get_u32(armv7m->core_cache->reg_list[ARMV7M_xPSR].value, 0, 32);
+       r = armv7m->core_cache->reg_list + ARMV7M_xPSR;
+       xPSR = buf_get_u32(r->value, 0, 32);
 
 #ifdef ARMV7_GDB_HACKS
+       /* FIXME this breaks on scan chains with more than one Cortex-M3.
+        * Instead, each CM3 should have its own dummy value...
+        */
        /* copy real xpsr reg for gdb, setting thumb bit */
        buf_set_u32(armv7m_gdb_dummy_cpsr_value, 0, 32, xPSR);
        buf_set_u32(armv7m_gdb_dummy_cpsr_value, 5, 1, 1);
-       armv7m_gdb_dummy_cpsr_reg.valid = armv7m->core_cache->reg_list[ARMV7M_xPSR].valid;
-       armv7m_gdb_dummy_cpsr_reg.dirty = armv7m->core_cache->reg_list[ARMV7M_xPSR].dirty;
+       armv7m_gdb_dummy_cpsr_reg.valid = r->valid;
+       armv7m_gdb_dummy_cpsr_reg.dirty = r->dirty;
 #endif
 
        /* For IT instructions xPSR must be reloaded on resume and clear on debug exec */
        if (xPSR & 0xf00)
        {
-               armv7m->core_cache->reg_list[ARMV7M_xPSR].dirty = armv7m->core_cache->reg_list[ARMV7M_xPSR].valid;
+               r->dirty = r->valid;
                cortex_m3_store_core_reg_u32(target, ARMV7M_REGISTER_CORE_GP, 16, xPSR &~ 0xff);
        }
 
-       /* Now we can load SP core registers */
-       for (i = ARMV7M_PRIMASK; i < ARMV7NUMCOREREGS; i++)
-       {
-               if (!armv7m->core_cache->reg_list[i].valid)
-                       armv7m->read_core_reg(target, i);
-       }
-
        /* Are we in an exception handler */
        if (xPSR & 0x1FF)
        {
                armv7m->core_mode = ARMV7M_MODE_HANDLER;
                armv7m->exception_number = (xPSR & 0x1FF);
+
+               arm->core_mode = ARM_MODE_HANDLER;
+               arm->map = armv7m_msp_reg_map;
        }
        else
        {
-               armv7m->core_mode = buf_get_u32(armv7m->core_cache->reg_list[ARMV7M_CONTROL].value, 0, 1);
+               unsigned control = buf_get_u32(armv7m->core_cache
+                               ->reg_list[ARMV7M_CONTROL].value, 0, 2);
+
+               /* is this thread privileged? */
+               armv7m->core_mode = control & 1;
+               arm->core_mode = armv7m->core_mode
+                               ? ARM_MODE_USER_THREAD
+                               : ARM_MODE_THREAD;
+
+               /* which stack is it using? */
+               if (control & 2)
+                       arm->map = armv7m_psp_reg_map;
+               else
+                       arm->map = armv7m_msp_reg_map;
+
                armv7m->exception_number = 0;
        }
 
@@ -443,24 +510,26 @@ int cortex_m3_debug_entry(target_t *target)
 
        LOG_DEBUG("entered debug state in core mode: %s at PC 0x%" PRIx32 ", target->state: %s",
                armv7m_mode_strings[armv7m->core_mode],
-               *(uint32_t*)(armv7m->core_cache->reg_list[15].value),
-               Jim_Nvp_value2name_simple( nvp_target_state, target->state )->name);
+               *(uint32_t*)(arm->pc->value),
+               target_state_name(target));
 
        if (armv7m->post_debug_entry)
-               armv7m->post_debug_entry(target);
+       {
+               retval = armv7m->post_debug_entry(target);
+               if (retval != ERROR_OK)
+                       return retval;
+       }
 
        return ERROR_OK;
 }
 
-int cortex_m3_poll(target_t *target)
+static int cortex_m3_poll(struct target *target)
 {
-       int retval;
+       int detected_failure = ERROR_OK;
+       int retval = ERROR_OK;
        enum target_state prev_target_state = target->state;
-
-       /* get pointers to arch-specific information */
-       armv7m_common_t *armv7m = target->arch_info;
-       cortex_m3_common_t *cortex_m3 = armv7m->arch_info;
-       swjdp_common_t *swjdp = &armv7m->swjdp_info;
+       struct cortex_m3_common *cortex_m3 = target_to_cm3(target);
+       struct adiv5_dap *swjdp = &cortex_m3->armv7m.dap;
 
        /* Read from Debug Halting Control and Status Register */
        retval = mem_ap_read_atomic_u32(swjdp, DCB_DHCSR, &cortex_m3->dcb_dhcsr);
@@ -470,10 +539,32 @@ int cortex_m3_poll(target_t *target)
                return retval;
        }
 
+       /* Recover from lockup.  See ARMv7-M architecture spec,
+        * section B1.5.15 "Unrecoverable exception cases".
+        */
+       if (cortex_m3->dcb_dhcsr & S_LOCKUP) {
+               LOG_ERROR("%s -- clearing lockup after double fault",
+                               target_name(target));
+               cortex_m3_write_debug_halt_mask(target, C_HALT, 0);
+               target->debug_reason = DBG_REASON_DBGRQ;
+
+               /* We have to execute the rest (the "finally" equivalent, but
+                * still throw this exception again).
+                */
+               detected_failure = ERROR_FAIL;
+
+               /* refresh status bits */
+               retval = mem_ap_read_atomic_u32(swjdp, DCB_DHCSR, &cortex_m3->dcb_dhcsr);
+               if (retval != ERROR_OK)
+                       return retval;
+       }
+
        if (cortex_m3->dcb_dhcsr & S_RESET_ST)
        {
                /* check if still in reset */
-               mem_ap_read_atomic_u32(swjdp, DCB_DHCSR, &cortex_m3->dcb_dhcsr);
+               retval = mem_ap_read_atomic_u32(swjdp, DCB_DHCSR, &cortex_m3->dcb_dhcsr);
+               if (retval != ERROR_OK)
+                       return retval;
 
                if (cortex_m3->dcb_dhcsr & S_RESET_ST)
                {
@@ -484,8 +575,11 @@ int cortex_m3_poll(target_t *target)
 
        if (target->state == TARGET_RESET)
        {
-               /* Cannot switch context while running so endreset is called with target->state == TARGET_RESET */
-               LOG_DEBUG("Exit from reset with dcb_dhcsr 0x%" PRIx32 "", cortex_m3->dcb_dhcsr);
+               /* Cannot switch context while running so endreset is
+                * called with target->state == TARGET_RESET
+                */
+               LOG_DEBUG("Exit from reset with dcb_dhcsr 0x%" PRIx32,
+                               cortex_m3->dcb_dhcsr);
                cortex_m3_endreset_event(target);
                target->state = TARGET_RUNNING;
                prev_target_state = TARGET_RUNNING;
@@ -500,6 +594,9 @@ int cortex_m3_poll(target_t *target)
                        if ((retval = cortex_m3_debug_entry(target)) != ERROR_OK)
                                return retval;
 
+                       if (arm_semihosting(target, &retval) != 0)
+                               return retval;
+
                        target_call_event_callbacks(target, TARGET_EVENT_HALTED);
                }
                if (prev_target_state == TARGET_DEBUG_RUNNING)
@@ -512,24 +609,30 @@ int cortex_m3_poll(target_t *target)
                }
        }
 
-       /*
-       if (cortex_m3->dcb_dhcsr & S_SLEEP)
-               target->state = TARGET_SLEEP;
-       */
+       /* REVISIT when S_SLEEP is set, it's in a Sleep or DeepSleep state.
+        * How best to model low power modes?
+        */
 
-#if 0
-       /* Read Debug Fault Status Register, added to figure out the lockup when running flashtest.script  */
-       mem_ap_read_atomic_u32(swjdp, NVIC_DFSR, &cortex_m3->nvic_dfsr);
-       LOG_DEBUG("dcb_dhcsr 0x%x, nvic_dfsr 0x%x, target->state: %s", cortex_m3->dcb_dhcsr, cortex_m3->nvic_dfsr, Jim_Nvp_value2name_simple( nvp_target_state, target->state )->name );
-#endif
+       if (target->state == TARGET_UNKNOWN)
+       {
+               /* check if processor is retiring instructions */
+               if (cortex_m3->dcb_dhcsr & S_RETIRE_ST)
+               {
+                       target->state = TARGET_RUNNING;
+                       retval = ERROR_OK;
+               }
+       }
 
-       return ERROR_OK;
+       /* Did we detect a failure condition that we cleared? */
+       if (detected_failure != ERROR_OK)
+               retval = detected_failure;
+       return retval;
 }
 
-int cortex_m3_halt(target_t *target)
+static int cortex_m3_halt(struct target *target)
 {
        LOG_DEBUG("target->state: %s",
-               Jim_Nvp_value2name_simple(nvp_target_state, target->state )->name);
+               target_state_name(target));
 
        if (target->state == TARGET_HALTED)
        {
@@ -568,39 +671,53 @@ int cortex_m3_halt(target_t *target)
        return ERROR_OK;
 }
 
-int cortex_m3_soft_reset_halt(struct target_s *target)
+static int cortex_m3_soft_reset_halt(struct target *target)
 {
-       /* get pointers to arch-specific information */
-       armv7m_common_t *armv7m = target->arch_info;
-       cortex_m3_common_t *cortex_m3 = armv7m->arch_info;
-       swjdp_common_t *swjdp = &armv7m->swjdp_info;
+       struct cortex_m3_common *cortex_m3 = target_to_cm3(target);
+       struct adiv5_dap *swjdp = &cortex_m3->armv7m.dap;
        uint32_t dcb_dhcsr = 0;
        int retval, timeout = 0;
 
-       /* Enter debug state on reset, cf. end_reset_event() */
-       mem_ap_write_u32(swjdp, DCB_DEMCR, TRCENA | VC_HARDERR | VC_BUSERR | VC_CORERESET);
+       /* Enter debug state on reset; restore DEMCR in endreset_event() */
+       retval = mem_ap_write_u32(swjdp, DCB_DEMCR,
+                       TRCENA | VC_HARDERR | VC_BUSERR | VC_CORERESET);
+       if (retval != ERROR_OK)
+               return retval;
 
-       /* Request a reset */
-       mem_ap_write_atomic_u32(swjdp, NVIC_AIRCR, AIRCR_VECTKEY | AIRCR_VECTRESET);
+       /* Request a core-only reset */
+       retval = mem_ap_write_atomic_u32(swjdp, NVIC_AIRCR,
+                       AIRCR_VECTKEY | AIRCR_VECTRESET);
+       if (retval != ERROR_OK)
+               return retval;
        target->state = TARGET_RESET;
 
        /* registers are now invalid */
-       armv7m_invalidate_core_regs(target);
+       register_cache_invalidate(cortex_m3->armv7m.core_cache);
 
        while (timeout < 100)
        {
                retval = mem_ap_read_atomic_u32(swjdp, DCB_DHCSR, &dcb_dhcsr);
                if (retval == ERROR_OK)
                {
-                       mem_ap_read_atomic_u32(swjdp, NVIC_DFSR, &cortex_m3->nvic_dfsr);
-                       if ((dcb_dhcsr & S_HALT) && (cortex_m3->nvic_dfsr & DFSR_VCATCH))
+                       retval = mem_ap_read_atomic_u32(swjdp, NVIC_DFSR,
+                                       &cortex_m3->nvic_dfsr);
+                       if (retval != ERROR_OK)
+                               return retval;
+                       if ((dcb_dhcsr & S_HALT)
+                                       && (cortex_m3->nvic_dfsr & DFSR_VCATCH))
                        {
-                               LOG_DEBUG("system reset-halted, dcb_dhcsr 0x%" PRIx32 ", nvic_dfsr 0x%" PRIx32 "", dcb_dhcsr, cortex_m3->nvic_dfsr);
+                               LOG_DEBUG("system reset-halted, DHCSR 0x%08x, "
+                                       "DFSR 0x%08x",
+                                       (unsigned) dcb_dhcsr,
+                                       (unsigned) cortex_m3->nvic_dfsr);
                                cortex_m3_poll(target);
+                               /* FIXME restore user's vector catch config */
                                return ERROR_OK;
                        }
                        else
-                               LOG_DEBUG("waiting for system reset-halt, dcb_dhcsr 0x%" PRIx32 ", %i ms", dcb_dhcsr, timeout);
+                               LOG_DEBUG("waiting for system reset-halt, "
+                                       "DHCSR 0x%08x, %d ms",
+                                       (unsigned) dcb_dhcsr, timeout);
                }
                timeout++;
                alive_sleep(1);
@@ -609,12 +726,26 @@ int cortex_m3_soft_reset_halt(struct target_s *target)
        return ERROR_OK;
 }
 
-int cortex_m3_resume(struct target_s *target, int current, uint32_t address, int handle_breakpoints, int debug_execution)
+static void cortex_m3_enable_breakpoints(struct target *target)
 {
-       /* get pointers to arch-specific information */
-       armv7m_common_t *armv7m = target->arch_info;
-       breakpoint_t *breakpoint = NULL;
+       struct breakpoint *breakpoint = target->breakpoints;
+
+       /* set any pending breakpoints */
+       while (breakpoint)
+       {
+               if (!breakpoint->set)
+                       cortex_m3_set_breakpoint(target, breakpoint);
+               breakpoint = breakpoint->next;
+       }
+}
+
+static int cortex_m3_resume(struct target *target, int current,
+               uint32_t address, int handle_breakpoints, int debug_execution)
+{
+       struct armv7m_common *armv7m = target_to_armv7m(target);
+       struct breakpoint *breakpoint = NULL;
        uint32_t resume_pc;
+       struct reg *r;
 
        if (target->state != TARGET_HALTED)
        {
@@ -631,30 +762,50 @@ int cortex_m3_resume(struct target_s *target, int current, uint32_t address, int
 
        if (debug_execution)
        {
+               r = armv7m->core_cache->reg_list + ARMV7M_PRIMASK;
+
                /* Disable interrupts */
-               /* We disable interrupts in the PRIMASK register instead of masking with C_MASKINTS,
-                * This is probably the same issue as Cortex-M3 Errata  377493:
-                * C_MASKINTS in parallel with disabled interrupts can cause local faults to not be taken. */
-               buf_set_u32(armv7m->core_cache->reg_list[ARMV7M_PRIMASK].value, 0, 32, 1);
-               armv7m->core_cache->reg_list[ARMV7M_PRIMASK].dirty = 1;
-               armv7m->core_cache->reg_list[ARMV7M_PRIMASK].valid = 1;
+               /* We disable interrupts in the PRIMASK register instead of
+                * masking with C_MASKINTS.  This is probably the same issue
+                * as Cortex-M3 Erratum 377493 (fixed in r1p0):  C_MASKINTS
+                * in parallel with disabled interrupts can cause local faults
+                * to not be taken.
+                *
+                * REVISIT this clearly breaks non-debug execution, since the
+                * PRIMASK register state isn't saved/restored...  workaround
+                * by never resuming app code after debug execution.
+                */
+               buf_set_u32(r->value, 0, 1, 1);
+               r->dirty = true;
+               r->valid = true;
 
                /* Make sure we are in Thumb mode */
-               buf_set_u32(armv7m->core_cache->reg_list[ARMV7M_xPSR].value, 0, 32,
-                       buf_get_u32(armv7m->core_cache->reg_list[ARMV7M_xPSR].value, 0, 32) | (1 << 24));
-               armv7m->core_cache->reg_list[ARMV7M_xPSR].dirty = 1;
-               armv7m->core_cache->reg_list[ARMV7M_xPSR].valid = 1;
+               r = armv7m->core_cache->reg_list + ARMV7M_xPSR;
+               buf_set_u32(r->value, 24, 1, 1);
+               r->dirty = true;
+               r->valid = true;
        }
 
        /* current = 1: continue on current pc, otherwise continue at <address> */
+       r = armv7m->arm.pc;
        if (!current)
        {
-               buf_set_u32(armv7m->core_cache->reg_list[15].value, 0, 32, address);
-               armv7m->core_cache->reg_list[15].dirty = 1;
-               armv7m->core_cache->reg_list[15].valid = 1;
+               buf_set_u32(r->value, 0, 32, address);
+               r->dirty = true;
+               r->valid = true;
+       }
+
+       /* if we halted last time due to a bkpt instruction
+        * then we have to manually step over it, otherwise
+        * the core will break again */
+
+       if (!breakpoint_find(target, buf_get_u32(r->value, 0, 32))
+                       && !debug_execution)
+       {
+               armv7m_maybe_skip_bkpt_inst(target, NULL);
        }
 
-       resume_pc = buf_get_u32(armv7m->core_cache->reg_list[15].value, 0, 32);
+       resume_pc = buf_get_u32(r->value, 0, 32);
 
        armv7m_restore_context(target);
 
@@ -664,7 +815,9 @@ int cortex_m3_resume(struct target_s *target, int current, uint32_t address, int
                /* Single step past breakpoint at current address */
                if ((breakpoint = breakpoint_find(target, resume_pc)))
                {
-                       LOG_DEBUG("unset breakpoint at 0x%8.8" PRIx32 "", breakpoint->address);
+                       LOG_DEBUG("unset breakpoint at 0x%8.8" PRIx32 " (ID: %d)",
+                                         breakpoint->address,
+                                         breakpoint->unique_id);
                        cortex_m3_unset_breakpoint(target, breakpoint);
                        cortex_m3_single_step_core(target);
                        cortex_m3_set_breakpoint(target, breakpoint);
@@ -677,7 +830,8 @@ int cortex_m3_resume(struct target_s *target, int current, uint32_t address, int
        target->debug_reason = DBG_REASON_NOTHALTED;
 
        /* registers are now invalid */
-       armv7m_invalidate_core_regs(target);
+       register_cache_invalidate(armv7m->core_cache);
+
        if (!debug_execution)
        {
                target->state = TARGET_RUNNING;
@@ -694,14 +848,16 @@ int cortex_m3_resume(struct target_s *target, int current, uint32_t address, int
        return ERROR_OK;
 }
 
-/* int irqstepcount=0; */
-int cortex_m3_step(struct target_s *target, int current, uint32_t address, int handle_breakpoints)
+/* int irqstepcount = 0; */
+static int cortex_m3_step(struct target *target, int current,
+               uint32_t address, int handle_breakpoints)
 {
-       /* get pointers to arch-specific information */
-       armv7m_common_t *armv7m = target->arch_info;
-       cortex_m3_common_t *cortex_m3 = armv7m->arch_info;
-       swjdp_common_t *swjdp = &armv7m->swjdp_info;
-       breakpoint_t *breakpoint = NULL;
+       struct cortex_m3_common *cortex_m3 = target_to_cm3(target);
+       struct armv7m_common *armv7m = &cortex_m3->armv7m;
+       struct adiv5_dap *swjdp = &armv7m->dap;
+       struct breakpoint *breakpoint = NULL;
+       struct reg *pc = armv7m->arm.pc;
+       bool bkpt_inst_found = false;
 
        if (target->state != TARGET_HALTED)
        {
@@ -711,12 +867,18 @@ int cortex_m3_step(struct target_s *target, int current, uint32_t address, int h
 
        /* current = 1: continue on current pc, otherwise continue at <address> */
        if (!current)
-               buf_set_u32(armv7m->core_cache->reg_list[15].value, 0, 32, address);
+               buf_set_u32(pc->value, 0, 32, address);
+
+       uint32_t pc_value = buf_get_u32(pc->value, 0, 32);
 
        /* the front-end may request us not to handle breakpoints */
-       if (handle_breakpoints)
-               if ((breakpoint = breakpoint_find(target, buf_get_u32(armv7m->core_cache->reg_list[15].value, 0, 32))))
+       if (handle_breakpoints) {
+               breakpoint = breakpoint_find(target, pc_value);
+               if (breakpoint)
                        cortex_m3_unset_breakpoint(target, breakpoint);
+       }
+
+       armv7m_maybe_skip_bkpt_inst(target, &bkpt_inst_found);
 
        target->debug_reason = DBG_REASON_SINGLESTEP;
 
@@ -724,101 +886,111 @@ int cortex_m3_step(struct target_s *target, int current, uint32_t address, int h
 
        target_call_event_callbacks(target, TARGET_EVENT_RESUMED);
 
-       /* set step and clear halt */
-       cortex_m3_write_debug_halt_mask(target, C_STEP, C_HALT);
-       mem_ap_read_atomic_u32(swjdp, DCB_DHCSR, &cortex_m3->dcb_dhcsr);
+       /* if no bkpt instruction is found at pc then we can perform
+        * a normal step, otherwise we have to manually step over the bkpt
+        * instruction - as such simulate a step */
+       if (bkpt_inst_found == false)
+       {
+               /* set step and clear halt */
+               cortex_m3_write_debug_halt_mask(target, C_STEP, C_HALT);
+       }
+
+       int retval;
+       retval = mem_ap_read_atomic_u32(swjdp, DCB_DHCSR, &cortex_m3->dcb_dhcsr);
+       if (retval != ERROR_OK)
+               return retval;
 
        /* registers are now invalid */
-       armv7m_invalidate_core_regs(target);
+       register_cache_invalidate(cortex_m3->armv7m.core_cache);
 
        if (breakpoint)
                cortex_m3_set_breakpoint(target, breakpoint);
 
-       LOG_DEBUG("target stepped dcb_dhcsr = 0x%" PRIx32 " nvic_icsr = 0x%" PRIx32 "", cortex_m3->dcb_dhcsr, cortex_m3->nvic_icsr);
+       LOG_DEBUG("target stepped dcb_dhcsr = 0x%" PRIx32
+                       " nvic_icsr = 0x%" PRIx32,
+                       cortex_m3->dcb_dhcsr, cortex_m3->nvic_icsr);
 
-       cortex_m3_debug_entry(target);
+       retval = cortex_m3_debug_entry(target);
+       if (retval != ERROR_OK)
+               return retval;
        target_call_event_callbacks(target, TARGET_EVENT_HALTED);
 
-       LOG_DEBUG("target stepped dcb_dhcsr = 0x%" PRIx32 " nvic_icsr = 0x%" PRIx32 "", cortex_m3->dcb_dhcsr, cortex_m3->nvic_icsr);
+       LOG_DEBUG("target stepped dcb_dhcsr = 0x%" PRIx32
+                       " nvic_icsr = 0x%" PRIx32,
+                       cortex_m3->dcb_dhcsr, cortex_m3->nvic_icsr);
+
        return ERROR_OK;
 }
 
-int cortex_m3_assert_reset(target_t *target)
+static int cortex_m3_assert_reset(struct target *target)
 {
-       armv7m_common_t *armv7m = target->arch_info;
-       cortex_m3_common_t *cortex_m3 = armv7m->arch_info;
-       swjdp_common_t *swjdp = &armv7m->swjdp_info;
-       int assert_srst = 1;
+       struct cortex_m3_common *cortex_m3 = target_to_cm3(target);
+       struct adiv5_dap *swjdp = &cortex_m3->armv7m.dap;
+       enum cortex_m3_soft_reset_config reset_config = cortex_m3->soft_reset_config;
 
        LOG_DEBUG("target->state: %s",
-               Jim_Nvp_value2name_simple( nvp_target_state, target->state )->name );
+               target_state_name(target));
 
        enum reset_types jtag_reset_config = jtag_get_reset_config();
-       if (!(jtag_reset_config & RESET_HAS_SRST))
-       {
-               LOG_ERROR("Can't assert SRST");
-               return ERROR_FAIL;
+
+       if (target_has_event_action(target, TARGET_EVENT_RESET_ASSERT)) {
+               /* allow scripts to override the reset event */
+
+               target_handle_event(target, TARGET_EVENT_RESET_ASSERT);
+               register_cache_invalidate(cortex_m3->armv7m.core_cache);
+               target->state = TARGET_RESET;
+
+               return ERROR_OK;
        }
 
        /* Enable debug requests */
-       mem_ap_read_atomic_u32(swjdp, DCB_DHCSR, &cortex_m3->dcb_dhcsr);
+       int retval;
+       retval = mem_ap_read_atomic_u32(swjdp, DCB_DHCSR, &cortex_m3->dcb_dhcsr);
+       if (retval != ERROR_OK)
+               return retval;
        if (!(cortex_m3->dcb_dhcsr & C_DEBUGEN))
-               mem_ap_write_u32(swjdp, DCB_DHCSR, DBGKEY | C_DEBUGEN);
+       {
+               retval = mem_ap_write_u32(swjdp, DCB_DHCSR, DBGKEY | C_DEBUGEN);
+               if (retval != ERROR_OK)
+                       return retval;
+       }
 
-       mem_ap_write_u32(swjdp, DCB_DCRDR, 0 );
+       retval = mem_ap_write_u32(swjdp, DCB_DCRDR, 0);
+       if (retval != ERROR_OK)
+               return retval;
 
        if (!target->reset_halt)
        {
                /* Set/Clear C_MASKINTS in a separate operation */
                if (cortex_m3->dcb_dhcsr & C_MASKINTS)
-                       mem_ap_write_atomic_u32(swjdp, DCB_DHCSR, DBGKEY | C_DEBUGEN | C_HALT);
+               {
+                       retval = mem_ap_write_atomic_u32(swjdp, DCB_DHCSR,
+                                       DBGKEY | C_DEBUGEN | C_HALT);
+                       if (retval != ERROR_OK)
+                               return retval;
+               }
 
                /* clear any debug flags before resuming */
                cortex_m3_clear_halt(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() */
-               mem_ap_write_atomic_u32(swjdp, DCB_DEMCR, TRCENA | VC_HARDERR | VC_BUSERR | VC_CORERESET);
-       }
-
-       /* following hack is to handle luminary reset
-        * when srst is asserted the luminary device seesm to also clear the debug registers
-        * which does not match the armv7 debug TRM */
-
-       if (strcmp(target->variant, "lm3s") == 0)
-       {
-               /* get revision of lm3s target, only early silicon has this issue
-                * Fury Rev B, DustDevil Rev B, Tempest all ok */
-
-               uint32_t did0;
-
-               if (target_read_u32(target, 0x400fe000, &did0) == ERROR_OK)
-               {
-                       switch ((did0 >> 16) & 0xff)
-                       {
-                               case 0:
-                                       /* all Sandstorm suffer issue */
-                                       assert_srst = 0;
-                                       break;
-
-                               case 1:
-                               case 3:
-                                       /* only Fury/DustDevil rev A suffer reset problems */
-                                       if (((did0 >> 8) & 0xff) == 0)
-                                               assert_srst = 0;
-                                       break;
-                       }
-               }
+               /* 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?
+                */
+               retval = mem_ap_write_atomic_u32(swjdp, DCB_DEMCR,
+                               TRCENA | VC_HARDERR | VC_BUSERR | VC_CORERESET);
+               if (retval != ERROR_OK)
+                       return retval;
        }
 
-       if (assert_srst)
+       if (jtag_reset_config & RESET_HAS_SRST)
        {
                /* default to asserting srst */
                if (jtag_reset_config & RESET_SRST_PULLS_TRST)
@@ -832,26 +1004,44 @@ int cortex_m3_assert_reset(target_t *target)
        }
        else
        {
-               /* this causes the luminary device to reset using the watchdog */
-               mem_ap_write_atomic_u32(swjdp, NVIC_AIRCR, AIRCR_VECTKEY | AIRCR_SYSRESETREQ);
-               LOG_DEBUG("Using Luminary Reset: SYSRESETREQ");
+               /* Use a standard Cortex-M3 software reset mechanism.
+                * We default to using VECRESET as it is supported on all current cores.
+                * This has the disadvantage of not resetting the peripherals, so a
+                * reset-init event handler is needed to perform any peripheral resets.
+                */
+               retval = mem_ap_write_atomic_u32(swjdp, NVIC_AIRCR,
+                               AIRCR_VECTKEY | ((reset_config == CORTEX_M3_RESET_SYSRESETREQ)
+                               ? AIRCR_SYSRESETREQ : AIRCR_VECTRESET));
+               if (retval != ERROR_OK)
+                       return retval;
+
+               LOG_DEBUG("Using Cortex-M3 %s", (reset_config == CORTEX_M3_RESET_SYSRESETREQ)
+                               ? "SYSRESETREQ" : "VECTRESET");
+
+               if (reset_config == CORTEX_M3_RESET_VECTRESET) {
+                       LOG_WARNING("Only resetting the Cortex-M3 core, use a reset-init event "
+                                       "handler to reset any peripherals");
+               }
 
                {
-                       /* I do not know why this is necessary, but it fixes strange effects
-                        * (step/resume cause a NMI after reset) on LM3S6918 -- Michael Schwingen */
+                       /* I do not know why this is necessary, but it
+                        * fixes strange effects (step/resume cause NMI
+                        * after reset) on LM3S6918 -- Michael Schwingen
+                        */
                        uint32_t tmp;
-                       mem_ap_read_atomic_u32(swjdp, NVIC_AIRCR, &tmp);
+                       retval = mem_ap_read_atomic_u32(swjdp, NVIC_AIRCR, &tmp);
+                       if (retval != ERROR_OK)
+                               return retval;
                }
        }
 
        target->state = TARGET_RESET;
        jtag_add_sleep(50000);
 
-       armv7m_invalidate_core_regs(target);
+       register_cache_invalidate(cortex_m3->armv7m.core_cache);
 
        if (target->reset_halt)
        {
-               int retval;
                if ((retval = target_halt(target)) != ERROR_OK)
                        return retval;
        }
@@ -859,10 +1049,10 @@ int cortex_m3_assert_reset(target_t *target)
        return ERROR_OK;
 }
 
-int cortex_m3_deassert_reset(target_t *target)
+static int cortex_m3_deassert_reset(struct target *target)
 {
        LOG_DEBUG("target->state: %s",
-               Jim_Nvp_value2name_simple(nvp_target_state, target->state )->name);
+               target_state_name(target));
 
        /* deassert reset lines */
        jtag_add_reset(0, 0);
@@ -870,40 +1060,24 @@ int cortex_m3_deassert_reset(target_t *target)
        return ERROR_OK;
 }
 
-void cortex_m3_enable_breakpoints(struct target_s *target)
-{
-       breakpoint_t *breakpoint = target->breakpoints;
-
-       /* set any pending breakpoints */
-       while (breakpoint)
-       {
-               if (breakpoint->set == 0)
-                       cortex_m3_set_breakpoint(target, breakpoint);
-               breakpoint = breakpoint->next;
-       }
-}
-
-int cortex_m3_set_breakpoint(struct target_s *target, breakpoint_t *breakpoint)
+static int
+cortex_m3_set_breakpoint(struct target *target, struct breakpoint *breakpoint)
 {
        int retval;
-       int fp_num=0;
+       int fp_num = 0;
        uint32_t hilo;
-
-       /* get pointers to arch-specific information */
-       armv7m_common_t *armv7m = target->arch_info;
-       cortex_m3_common_t *cortex_m3 = armv7m->arch_info;
-
-       cortex_m3_fp_comparator_t * comparator_list = cortex_m3->fp_comparator_list;
+       struct cortex_m3_common *cortex_m3 = target_to_cm3(target);
+       struct cortex_m3_fp_comparator *comparator_list = cortex_m3->fp_comparator_list;
 
        if (breakpoint->set)
        {
-               LOG_WARNING("breakpoint already set");
+               LOG_WARNING("breakpoint (BPID: %d) already set", breakpoint->unique_id);
                return ERROR_OK;
        }
 
        if (cortex_m3->auto_bp_type)
        {
-               breakpoint->type = (breakpoint->address < 0x20000000) ? BKPT_HARD : BKPT_SOFT;
+               breakpoint->type = BKPT_TYPE_BY_ADDR(breakpoint->address);
        }
 
        if (breakpoint->type == BKPT_HARD)
@@ -912,9 +1086,8 @@ int cortex_m3_set_breakpoint(struct target_s *target, breakpoint_t *breakpoint)
                        fp_num++;
                if (fp_num >= cortex_m3->fp_num_code)
                {
-                       LOG_DEBUG("ERROR Can not find free FP Comparator");
-                       LOG_WARNING("ERROR Can not find free FP Comparator");
-                       exit(-1);
+                       LOG_ERROR("Can not find free FPB Comparator!");
+                       return ERROR_FAIL;
                }
                breakpoint->set = fp_num + 1;
                hilo = (breakpoint->address & 0x2) ? FPCR_REPLACE_BKPT_HIGH : FPCR_REPLACE_BKPT_LOW;
@@ -931,28 +1104,43 @@ int cortex_m3_set_breakpoint(struct target_s *target, breakpoint_t *breakpoint)
        else if (breakpoint->type == BKPT_SOFT)
        {
                uint8_t code[4];
-               buf_set_u32(code, 0, 32, ARMV7M_T_BKPT(0x11));
-               if ((retval = target_read_memory(target, breakpoint->address & 0xFFFFFFFE, breakpoint->length, 1, breakpoint->orig_instr)) != ERROR_OK)
-               {
+
+               /* 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));
+               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->unique_id,
+                         (int)(breakpoint->type),
+                         breakpoint->address,
+                         breakpoint->length,
+                         breakpoint->set);
+
        return ERROR_OK;
 }
 
-int cortex_m3_unset_breakpoint(struct target_s *target, breakpoint_t *breakpoint)
+static int
+cortex_m3_unset_breakpoint(struct target *target, struct breakpoint *breakpoint)
 {
        int retval;
-       /* get pointers to arch-specific information */
-       armv7m_common_t *armv7m = target->arch_info;
-       cortex_m3_common_t *cortex_m3 = armv7m->arch_info;
-       cortex_m3_fp_comparator_t * comparator_list = cortex_m3->fp_comparator_list;
+       struct cortex_m3_common *cortex_m3 = target_to_cm3(target);
+       struct cortex_m3_fp_comparator * comparator_list = cortex_m3->fp_comparator_list;
 
        if (!breakpoint->set)
        {
@@ -960,6 +1148,13 @@ int cortex_m3_unset_breakpoint(struct target_s *target, breakpoint_t *breakpoint
                return ERROR_OK;
        }
 
+       LOG_DEBUG("BPID: %d, Type: %d, Address: 0x%08" PRIx32 " Length: %d (set=%d)",
+                         breakpoint->unique_id,
+                         (int)(breakpoint->type),
+                         breakpoint->address,
+                         breakpoint->length,
+                         breakpoint->set);
+
        if (breakpoint->type == BKPT_HARD)
        {
                int fp_num = breakpoint->set - 1;
@@ -990,20 +1185,19 @@ int cortex_m3_unset_breakpoint(struct target_s *target, breakpoint_t *breakpoint
                        }
                }
        }
-       breakpoint->set = 0;
+       breakpoint->set = false;
 
        return ERROR_OK;
 }
 
-int cortex_m3_add_breakpoint(struct target_s *target, breakpoint_t *breakpoint)
+static int
+cortex_m3_add_breakpoint(struct target *target, struct breakpoint *breakpoint)
 {
-       /* get pointers to arch-specific information */
-       armv7m_common_t *armv7m = target->arch_info;
-       cortex_m3_common_t *cortex_m3 = armv7m->arch_info;
+       struct cortex_m3_common *cortex_m3 = target_to_cm3(target);
 
        if (cortex_m3->auto_bp_type)
        {
-               breakpoint->type = (breakpoint->address < 0x20000000) ? BKPT_HARD : BKPT_SOFT;
+               breakpoint->type = BKPT_TYPE_BY_ADDR(breakpoint->address);
 #ifdef ARMV7_GDB_HACKS
                if (breakpoint->length != 2) {
                        /* XXX Hack: Replace all breakpoints with length != 2 with
@@ -1014,16 +1208,18 @@ int cortex_m3_add_breakpoint(struct target_s *target, breakpoint_t *breakpoint)
 #endif
        }
 
-       if ((breakpoint->type == BKPT_HARD) && (breakpoint->address >= 0x20000000))
-       {
-               LOG_INFO("flash patch comparator requested outside code memory region");
-               return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
-       }
+       if(breakpoint->type != BKPT_TYPE_BY_ADDR(breakpoint->address)) {
+               if (breakpoint->type == BKPT_HARD)
+               {
+                       LOG_INFO("flash patch comparator requested outside code memory region");
+                       return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
+               }
 
-       if ((breakpoint->type == BKPT_SOFT) && (breakpoint->address < 0x20000000))
-       {
-               LOG_INFO("soft breakpoint requested in code (flash) memory region");
-               return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
+               if (breakpoint->type == BKPT_SOFT)
+               {
+                       LOG_INFO("soft breakpoint requested in code (flash) memory region");
+                       return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
+               }
        }
 
        if ((breakpoint->type == BKPT_HARD) && (cortex_m3->fp_code_available < 1))
@@ -1040,17 +1236,16 @@ int cortex_m3_add_breakpoint(struct target_s *target, breakpoint_t *breakpoint)
 
        if (breakpoint->type == BKPT_HARD)
                cortex_m3->fp_code_available--;
-       cortex_m3_set_breakpoint(target, breakpoint);
 
-       return ERROR_OK;
+       return cortex_m3_set_breakpoint(target, breakpoint);
 }
 
-int cortex_m3_remove_breakpoint(struct target_s *target, breakpoint_t *breakpoint)
+static int
+cortex_m3_remove_breakpoint(struct target *target, struct breakpoint *breakpoint)
 {
-       /* get pointers to arch-specific information */
-       armv7m_common_t *armv7m = target->arch_info;
-       cortex_m3_common_t *cortex_m3 = armv7m->arch_info;
+       struct cortex_m3_common *cortex_m3 = target_to_cm3(target);
 
+       /* REVISIT why check? FBP can be updated with core running ... */
        if (target->state != TARGET_HALTED)
        {
                LOG_WARNING("target not halted");
@@ -1059,7 +1254,7 @@ int cortex_m3_remove_breakpoint(struct target_s *target, breakpoint_t *breakpoin
 
        if (cortex_m3->auto_bp_type)
        {
-               breakpoint->type = (breakpoint->address < 0x20000000) ? BKPT_HARD : BKPT_SOFT;
+               breakpoint->type = BKPT_TYPE_BY_ADDR(breakpoint->address);
        }
 
        if (breakpoint->set)
@@ -1073,122 +1268,165 @@ int cortex_m3_remove_breakpoint(struct target_s *target, breakpoint_t *breakpoin
        return ERROR_OK;
 }
 
-int cortex_m3_set_watchpoint(struct target_s *target, watchpoint_t *watchpoint)
+static int
+cortex_m3_set_watchpoint(struct target *target, struct watchpoint *watchpoint)
 {
-       int dwt_num=0;
+       int dwt_num = 0;
        uint32_t mask, temp;
-
-       /* get pointers to arch-specific information */
-       armv7m_common_t *armv7m = target->arch_info;
-       cortex_m3_common_t *cortex_m3 = armv7m->arch_info;
-       cortex_m3_dwt_comparator_t * comparator_list = cortex_m3->dwt_comparator_list;
-
-       if (watchpoint->set)
-       {
-               LOG_WARNING("watchpoint already set");
-               return ERROR_OK;
-       }
-
-       if (watchpoint->mask == 0xffffffffu)
-       {
-               while (comparator_list[dwt_num].used && (dwt_num < cortex_m3->dwt_num_comp))
-                       dwt_num++;
-               if (dwt_num >= cortex_m3->dwt_num_comp)
-               {
-                       LOG_DEBUG("ERROR Can not find free DWT Comparator");
-                       LOG_WARNING("ERROR Can not find free DWT Comparator");
-                       return -1;
-               }
-               watchpoint->set = dwt_num + 1;
-               mask = 0;
-               temp = watchpoint->length;
-               while (temp > 1)
-               {
-                       temp = temp / 2;
-                       mask++;
-               }
-               comparator_list[dwt_num].used = 1;
-               comparator_list[dwt_num].comp = watchpoint->address;
-               comparator_list[dwt_num].mask = mask;
-               comparator_list[dwt_num].function = watchpoint->rw + 5;
-               target_write_u32(target, comparator_list[dwt_num].dwt_comparator_address, comparator_list[dwt_num].comp);
-               target_write_u32(target, comparator_list[dwt_num].dwt_comparator_address|0x4, comparator_list[dwt_num].mask);
-               target_write_u32(target, comparator_list[dwt_num].dwt_comparator_address|0x8, comparator_list[dwt_num].function);
-               LOG_DEBUG("dwt_num %i 0x%" PRIx32 " 0x%" PRIx32 " 0x%" PRIx32 "", dwt_num, comparator_list[dwt_num].comp, comparator_list[dwt_num].mask, comparator_list[dwt_num].function);
-       }
-       else
-       {
-               LOG_WARNING("Cannot watch data values");  /* Move this test to add_watchpoint */
-               return ERROR_OK;
+       struct cortex_m3_common *cortex_m3 = target_to_cm3(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
+        * count; send data trace info through ITM and TPIU; etc
+        */
+       struct cortex_m3_dwt_comparator *comparator;
+
+       for (comparator = cortex_m3->dwt_comparator_list;
+                       comparator->used && dwt_num < cortex_m3->dwt_num_comp;
+                       comparator++, dwt_num++)
+               continue;
+       if (dwt_num >= cortex_m3->dwt_num_comp)
+       {
+               LOG_ERROR("Can not find free DWT Comparator");
+               return ERROR_FAIL;
        }
-
+       comparator->used = 1;
+       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);
+
+       switch (watchpoint->rw) {
+       case WPT_READ:
+               comparator->function = 5;
+               break;
+       case WPT_WRITE:
+               comparator->function = 6;
+               break;
+       case WPT_ACCESS:
+               comparator->function = 7;
+               break;
+       }
+       target_write_u32(target, comparator->dwt_comparator_address + 8,
+                       comparator->function);
+
+       LOG_DEBUG("Watchpoint (ID %d) DWT%d 0x%08x 0x%x 0x%05x",
+                       watchpoint->unique_id, dwt_num,
+                       (unsigned) comparator->comp,
+                       (unsigned) comparator->mask,
+                       (unsigned) comparator->function);
        return ERROR_OK;
-
 }
 
-int cortex_m3_unset_watchpoint(struct target_s *target, watchpoint_t *watchpoint)
+static int
+cortex_m3_unset_watchpoint(struct target *target, struct watchpoint *watchpoint)
 {
-       /* get pointers to arch-specific information */
-       armv7m_common_t *armv7m = target->arch_info;
-       cortex_m3_common_t *cortex_m3 = armv7m->arch_info;
-       cortex_m3_dwt_comparator_t * comparator_list = cortex_m3->dwt_comparator_list;
+       struct cortex_m3_common *cortex_m3 = target_to_cm3(target);
+       struct cortex_m3_dwt_comparator *comparator;
        int dwt_num;
 
        if (!watchpoint->set)
        {
-               LOG_WARNING("watchpoint not set");
+               LOG_WARNING("watchpoint (wpid: %d) not set",
+                               watchpoint->unique_id);
                return ERROR_OK;
        }
 
        dwt_num = watchpoint->set - 1;
 
+       LOG_DEBUG("Watchpoint (ID %d) DWT%d address: 0x%08x clear",
+                       watchpoint->unique_id, dwt_num,
+                       (unsigned) watchpoint->address);
+
        if ((dwt_num < 0) || (dwt_num >= cortex_m3->dwt_num_comp))
        {
                LOG_DEBUG("Invalid DWT Comparator number in watchpoint");
                return ERROR_OK;
        }
-       comparator_list[dwt_num].used = 0;
-       comparator_list[dwt_num].function = 0;
-       target_write_u32(target, comparator_list[dwt_num].dwt_comparator_address|0x8, comparator_list[dwt_num].function);
 
-       watchpoint->set = 0;
+       comparator = cortex_m3->dwt_comparator_list + dwt_num;
+       comparator->used = 0;
+       comparator->function = 0;
+       target_write_u32(target, comparator->dwt_comparator_address + 8,
+                       comparator->function);
+
+       watchpoint->set = false;
 
        return ERROR_OK;
 }
 
-int cortex_m3_add_watchpoint(struct target_s *target, watchpoint_t *watchpoint)
+static int
+cortex_m3_add_watchpoint(struct target *target, struct watchpoint *watchpoint)
 {
-       /* get pointers to arch-specific information */
-       armv7m_common_t *armv7m = target->arch_info;
-       cortex_m3_common_t *cortex_m3 = armv7m->arch_info;
+       struct cortex_m3_common *cortex_m3 = target_to_cm3(target);
 
-       if (target->state != TARGET_HALTED)
+       if (cortex_m3->dwt_comp_available < 1)
        {
-               LOG_WARNING("target not halted");
-               return ERROR_TARGET_NOT_HALTED;
+               LOG_DEBUG("no comparators?");
+               return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
        }
 
-       if (cortex_m3->dwt_comp_available < 1)
-       {
+       /* hardware doesn't support data value masking */
+       if (watchpoint->mask != ~(uint32_t)0) {
+               LOG_DEBUG("watchpoint value masks not supported");
                return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
        }
 
-       if ((watchpoint->length != 1) && (watchpoint->length != 2) && (watchpoint->length != 4))
-       {
+       /* hardware allows address masks of up to 32K */
+       unsigned mask;
+
+       for (mask = 0; mask < 16; mask++) {
+               if ((1u << mask) == watchpoint->length)
+                       break;
+       }
+       if (mask == 16) {
+               LOG_DEBUG("unsupported watchpoint length");
+               return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
+       }
+       if (watchpoint->address & ((1 << mask) - 1)) {
+               LOG_DEBUG("watchpoint address is unaligned");
+               return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
+       }
+
+       /* Caller doesn't seem to be able to describe watching for data
+        * values of zero; that flags "no value".
+        *
+        * REVISIT This DWT may well be able to watch for specific data
+        * values.  Requires comparator #1 to set DATAVMATCH and match
+        * the data, and another comparator (DATAVADDR0) matching addr.
+        */
+       if (watchpoint->value) {
+               LOG_DEBUG("data value watchpoint not YET supported");
                return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
        }
 
        cortex_m3->dwt_comp_available--;
+       LOG_DEBUG("dwt_comp_available: %d", cortex_m3->dwt_comp_available);
 
        return ERROR_OK;
 }
 
-int cortex_m3_remove_watchpoint(struct target_s *target, watchpoint_t *watchpoint)
+static int
+cortex_m3_remove_watchpoint(struct target *target, struct watchpoint *watchpoint)
 {
-       /* get pointers to arch-specific information */
-       armv7m_common_t *armv7m = target->arch_info;
-       cortex_m3_common_t *cortex_m3 = armv7m->arch_info;
+       struct cortex_m3_common *cortex_m3 = target_to_cm3(target);
 
+       /* REVISIT why check? DWT can be updated with core running ... */
        if (target->state != TARGET_HALTED)
        {
                LOG_WARNING("target not halted");
@@ -1201,32 +1439,37 @@ int cortex_m3_remove_watchpoint(struct target_s *target, watchpoint_t *watchpoin
        }
 
        cortex_m3->dwt_comp_available++;
+       LOG_DEBUG("dwt_comp_available: %d", cortex_m3->dwt_comp_available);
 
        return ERROR_OK;
 }
 
-void cortex_m3_enable_watchpoints(struct target_s *target)
+static void cortex_m3_enable_watchpoints(struct target *target)
 {
-       watchpoint_t *watchpoint = target->watchpoints;
+       struct watchpoint *watchpoint = target->watchpoints;
 
        /* set any pending watchpoints */
        while (watchpoint)
        {
-               if (watchpoint->set == 0)
+               if (!watchpoint->set)
                        cortex_m3_set_watchpoint(target, watchpoint);
                watchpoint = watchpoint->next;
        }
 }
 
-int cortex_m3_load_core_reg_u32(struct target_s *target, enum armv7m_regtype type, uint32_t num, uint32_t * value)
+static int cortex_m3_load_core_reg_u32(struct target *target,
+               enum armv7m_regtype type, uint32_t num, uint32_t * value)
 {
        int retval;
-       /* get pointers to arch-specific information */
-       armv7m_common_t *armv7m = target->arch_info;
-       swjdp_common_t *swjdp = &armv7m->swjdp_info;
-
-       if ((type == ARMV7M_REGISTER_CORE_GP) && (num <= ARMV7M_PSP))
-       {
+       struct armv7m_common *armv7m = target_to_armv7m(target);
+       struct adiv5_dap *swjdp = &armv7m->dap;
+
+       /* NOTE:  we "know" here that the register identifiers used
+        * in the v7m header match the Cortex-M3 Debug Core Register
+        * Selector values for R0..R15, xPSR, MSP, and PSP.
+        */
+       switch (num) {
+       case 0 ... 18:
                /* read a normal core register */
                retval = cortexm3_dap_read_coreregister_u32(swjdp, value, num);
 
@@ -1236,124 +1479,137 @@ int cortex_m3_load_core_reg_u32(struct target_s *target, enum armv7m_regtype typ
                        return ERROR_JTAG_DEVICE_ERROR;
                }
                LOG_DEBUG("load from core reg %i  value 0x%" PRIx32 "",(int)num,*value);
-       }
-       else if (type == ARMV7M_REGISTER_CORE_SP) /* Special purpose core register */
-       {
-               /* read other registers */
+               break;
+
+       case ARMV7M_PRIMASK:
+       case ARMV7M_BASEPRI:
+       case ARMV7M_FAULTMASK:
+       case ARMV7M_CONTROL:
+               /* Cortex-M3 packages these four registers as bitfields
+                * in one Debug Core register.  So say r0 and r2 docs;
+                * it was removed from r1 docs, but still works.
+                */
                cortexm3_dap_read_coreregister_u32(swjdp, value, 20);
 
                switch (num)
                {
-                       case 19:
-                               *value = buf_get_u32((uint8_t*)value, 0, 8);
+                       case ARMV7M_PRIMASK:
+                               *value = buf_get_u32((uint8_t*)value, 0, 1);
                                break;
 
-                       case 20:
+                       case ARMV7M_BASEPRI:
                                *value = buf_get_u32((uint8_t*)value, 8, 8);
                                break;
 
-                       case 21:
-                               *value = buf_get_u32((uint8_t*)value, 16, 8);
+                       case ARMV7M_FAULTMASK:
+                               *value = buf_get_u32((uint8_t*)value, 16, 1);
                                break;
 
-                       case 22:
-                               *value = buf_get_u32((uint8_t*)value, 24, 8);
+                       case ARMV7M_CONTROL:
+                               *value = buf_get_u32((uint8_t*)value, 24, 2);
                                break;
                }
 
                LOG_DEBUG("load from special reg %i value 0x%" PRIx32 "", (int)num, *value);
-       }
-       else
-       {
+               break;
+
+       default:
                return ERROR_INVALID_ARGUMENTS;
        }
 
        return ERROR_OK;
 }
 
-int cortex_m3_store_core_reg_u32(struct target_s *target, enum armv7m_regtype type, uint32_t num, uint32_t value)
+static int cortex_m3_store_core_reg_u32(struct target *target,
+               enum armv7m_regtype type, uint32_t num, uint32_t value)
 {
        int retval;
        uint32_t reg;
-
-       /* get pointers to arch-specific information */
-       armv7m_common_t *armv7m = target->arch_info;
-       swjdp_common_t *swjdp = &armv7m->swjdp_info;
+       struct armv7m_common *armv7m = target_to_armv7m(target);
+       struct adiv5_dap *swjdp = &armv7m->dap;
 
 #ifdef ARMV7_GDB_HACKS
        /* If the LR register is being modified, make sure it will put us
         * in "thumb" mode, or an INVSTATE exception will occur. This is a
         * hack to deal with the fact that gdb will sometimes "forge"
         * return addresses, and doesn't set the LSB correctly (i.e., when
-        * printing expressions containing function calls, it sets LR=0.) */
-
-       if (num == 14)
+        * printing expressions containing function calls, it sets LR = 0.)
+        * Valid exception return codes have bit 0 set too.
+        */
+       if (num == ARMV7M_R14)
                value |= 0x01;
 #endif
 
-       if ((type == ARMV7M_REGISTER_CORE_GP) && (num <= ARMV7M_PSP))
-       {
+       /* NOTE:  we "know" here that the register identifiers used
+        * in the v7m header match the Cortex-M3 Debug Core Register
+        * Selector values for R0..R15, xPSR, MSP, and PSP.
+        */
+       switch (num) {
+       case 0 ... 18:
                retval = cortexm3_dap_write_coreregister_u32(swjdp, value, num);
                if (retval != ERROR_OK)
                {
-                       LOG_ERROR("JTAG failure %i", retval);
-                       armv7m->core_cache->reg_list[num].dirty = armv7m->core_cache->reg_list[num].valid;
+                       struct reg *r;
+
+                       LOG_ERROR("JTAG failure");
+                       r = armv7m->core_cache->reg_list + num;
+                       r->dirty = r->valid;
                        return ERROR_JTAG_DEVICE_ERROR;
                }
                LOG_DEBUG("write core reg %i value 0x%" PRIx32 "", (int)num, value);
-       }
-       else if (type == ARMV7M_REGISTER_CORE_SP) /* Special purpose core register */
-       {
-               /* write other registers */
-
+               break;
+
+       case ARMV7M_PRIMASK:
+       case ARMV7M_BASEPRI:
+       case ARMV7M_FAULTMASK:
+       case ARMV7M_CONTROL:
+               /* Cortex-M3 packages these four registers as bitfields
+                * in one Debug Core register.  So say r0 and r2 docs;
+                * it was removed from r1 docs, but still works.
+                */
                cortexm3_dap_read_coreregister_u32(swjdp, &reg, 20);
 
                switch (num)
                {
-                       case 19:
-                               buf_set_u32((uint8_t*)&reg, 0, 8, value);
+                       case ARMV7M_PRIMASK:
+                               buf_set_u32((uint8_t*)&reg, 0, 1, value);
                                break;
 
-                       case 20:
+                       case ARMV7M_BASEPRI:
                                buf_set_u32((uint8_t*)&reg, 8, 8, value);
                                break;
 
-                       case 21:
-                               buf_set_u32((uint8_t*)&reg, 16, 8, value);
+                       case ARMV7M_FAULTMASK:
+                               buf_set_u32((uint8_t*)&reg, 16, 1, value);
                                break;
 
-                       case 22:
-                               buf_set_u32((uint8_t*)&reg, 24, 8, value);
+                       case ARMV7M_CONTROL:
+                               buf_set_u32((uint8_t*)&reg, 24, 2, value);
                                break;
                }
 
                cortexm3_dap_write_coreregister_u32(swjdp, reg, 20);
 
                LOG_DEBUG("write special reg %i value 0x%" PRIx32 " ", (int)num, value);
-       }
-       else
-       {
+               break;
+
+       default:
                return ERROR_INVALID_ARGUMENTS;
        }
 
        return ERROR_OK;
 }
 
-int cortex_m3_read_memory(struct target_s *target, uint32_t address, uint32_t size, uint32_t count, uint8_t *buffer)
+static int cortex_m3_read_memory(struct target *target, uint32_t address,
+               uint32_t size, uint32_t count, uint8_t *buffer)
 {
-       /* get pointers to arch-specific information */
-       armv7m_common_t *armv7m = target->arch_info;
-       swjdp_common_t *swjdp = &armv7m->swjdp_info;
-       int retval;
-
-       /* sanitize arguments */
-       if (((size != 4) && (size != 2) && (size != 1)) || (count == 0) || !(buffer))
-               return ERROR_INVALID_ARGUMENTS;
+       struct armv7m_common *armv7m = target_to_armv7m(target);
+       struct adiv5_dap *swjdp = &armv7m->dap;
+       int retval = ERROR_INVALID_ARGUMENTS;
 
        /* cortex_m3 handles unaligned memory access */
-
-       switch (size)
-       {
+       if (count && buffer) {
+               switch (size) {
                case 4:
                        retval = mem_ap_read_buf_u32(swjdp, buffer, 4 * count, address);
                        break;
@@ -1363,27 +1619,21 @@ int cortex_m3_read_memory(struct target_s *target, uint32_t address, uint32_t si
                case 1:
                        retval = mem_ap_read_buf_u8(swjdp, buffer, count, address);
                        break;
-               default:
-                       LOG_ERROR("BUG: we shouldn't get here");
-                       exit(-1);
+               }
        }
 
        return retval;
 }
 
-int cortex_m3_write_memory(struct target_s *target, uint32_t address, uint32_t size, uint32_t count, uint8_t *buffer)
+static int cortex_m3_write_memory(struct target *target, uint32_t address,
+               uint32_t size, uint32_t count, const uint8_t *buffer)
 {
-       /* get pointers to arch-specific information */
-       armv7m_common_t *armv7m = target->arch_info;
-       swjdp_common_t *swjdp = &armv7m->swjdp_info;
-       int retval;
+       struct armv7m_common *armv7m = target_to_armv7m(target);
+       struct adiv5_dap *swjdp = &armv7m->dap;
+       int retval = ERROR_INVALID_ARGUMENTS;
 
-       /* sanitize arguments */
-       if (((size != 4) && (size != 2) && (size != 1)) || (count == 0) || !(buffer))
-               return ERROR_INVALID_ARGUMENTS;
-
-       switch (size)
-       {
+       if (count && buffer) {
+               switch (size) {
                case 4:
                        retval = mem_ap_write_buf_u32(swjdp, buffer, 4 * count, address);
                        break;
@@ -1393,40 +1643,174 @@ int cortex_m3_write_memory(struct target_s *target, uint32_t address, uint32_t s
                case 1:
                        retval = mem_ap_write_buf_u8(swjdp, buffer, count, address);
                        break;
-               default:
-                       LOG_ERROR("BUG: we shouldn't get here");
-                       exit(-1);
+               }
        }
 
        return retval;
 }
 
-int cortex_m3_bulk_write_memory(target_t *target, uint32_t address, uint32_t count, uint8_t *buffer)
+static int cortex_m3_bulk_write_memory(struct target *target, uint32_t address,
+               uint32_t count, const uint8_t *buffer)
 {
        return cortex_m3_write_memory(target, address, 4, count, buffer);
 }
 
-void cortex_m3_build_reg_cache(target_t *target)
+static int cortex_m3_init_target(struct command_context *cmd_ctx,
+               struct target *target)
 {
        armv7m_build_reg_cache(target);
+       return ERROR_OK;
 }
 
-int cortex_m3_init_target(struct command_context_s *cmd_ctx, struct target_s *target)
+/* REVISIT cache valid/dirty bits are unmaintained.  We could set "valid"
+ * on r/w if the core is not running, and clear on resume or reset ... or
+ * at least, in a post_restore_context() method.
+ */
+
+struct dwt_reg_state {
+       struct target   *target;
+       uint32_t        addr;
+       uint32_t        value;  /* scratch/cache */
+};
+
+static int cortex_m3_dwt_get_reg(struct reg *reg)
 {
-       cortex_m3_build_reg_cache(target);
-       return ERROR_OK;
+       struct dwt_reg_state *state = reg->arch_info;
+
+       return target_read_u32(state->target, state->addr, &state->value);
+}
+
+static int cortex_m3_dwt_set_reg(struct reg *reg, uint8_t *buf)
+{
+       struct dwt_reg_state *state = reg->arch_info;
+
+       return target_write_u32(state->target, state->addr,
+                       buf_get_u32(buf, 0, reg->size));
+}
+
+struct dwt_reg {
+       uint32_t        addr;
+       char            *name;
+       unsigned        size;
+};
+
+static struct dwt_reg dwt_base_regs[] = {
+       { DWT_CTRL, "dwt_ctrl", 32, },
+       /* NOTE that Erratum 532314 (fixed r2p0) affects CYCCNT:  it wrongly
+        * increments while the core is asleep.
+        */
+       { DWT_CYCCNT, "dwt_cyccnt", 32, },
+       /* plus some 8 bit counters, useful for profiling with TPIU */
+};
+
+static struct dwt_reg dwt_comp[] = {
+#define DWT_COMPARATOR(i) \
+               { DWT_COMP0 + 0x10 * (i), "dwt_" #i "_comp", 32, }, \
+               { DWT_MASK0 + 0x10 * (i), "dwt_" #i "_mask", 4, }, \
+               { DWT_FUNCTION0 + 0x10 * (i), "dwt_" #i "_function", 32, }
+       DWT_COMPARATOR(0),
+       DWT_COMPARATOR(1),
+       DWT_COMPARATOR(2),
+       DWT_COMPARATOR(3),
+#undef DWT_COMPARATOR
+};
+
+static const struct reg_arch_type dwt_reg_type = {
+       .get = cortex_m3_dwt_get_reg,
+       .set = cortex_m3_dwt_set_reg,
+};
+
+static void
+cortex_m3_dwt_addreg(struct target *t, struct reg *r, struct dwt_reg *d)
+{
+       struct dwt_reg_state *state;
+
+       state = calloc(1, sizeof *state);
+       if (!state)
+               return;
+       state->addr = d->addr;
+       state->target = t;
+
+       r->name = d->name;
+       r->size = d->size;
+       r->value = &state->value;
+       r->arch_info = state;
+       r->type = &dwt_reg_type;
+}
+
+static void
+cortex_m3_dwt_setup(struct cortex_m3_common *cm3, struct target *target)
+{
+       uint32_t dwtcr;
+       struct reg_cache *cache;
+       struct cortex_m3_dwt_comparator *comparator;
+       int reg, i;
+
+       target_read_u32(target, DWT_CTRL, &dwtcr);
+       if (!dwtcr) {
+               LOG_DEBUG("no DWT");
+               return;
+       }
+
+       cm3->dwt_num_comp = (dwtcr >> 28) & 0xF;
+       cm3->dwt_comp_available = cm3->dwt_num_comp;
+       cm3->dwt_comparator_list = calloc(cm3->dwt_num_comp,
+                       sizeof(struct cortex_m3_dwt_comparator));
+       if (!cm3->dwt_comparator_list) {
+fail0:
+               cm3->dwt_num_comp = 0;
+               LOG_ERROR("out of mem");
+               return;
+       }
+
+       cache = calloc(1, sizeof *cache);
+       if (!cache) {
+fail1:
+               free(cm3->dwt_comparator_list);
+               goto fail0;
+       }
+       cache->name = "cortex-m3 dwt registers";
+       cache->num_regs = 2 + cm3->dwt_num_comp * 3;
+       cache->reg_list = calloc(cache->num_regs, sizeof *cache->reg_list);
+       if (!cache->reg_list) {
+               free(cache);
+               goto fail1;
+       }
+
+       for (reg = 0; reg < 2; reg++)
+               cortex_m3_dwt_addreg(target, cache->reg_list + reg,
+                               dwt_base_regs + reg);
+
+       comparator = cm3->dwt_comparator_list;
+       for (i = 0; i < cm3->dwt_num_comp; i++, comparator++) {
+               int j;
+
+               comparator->dwt_comparator_address = DWT_COMP0 + 0x10 * i;
+               for (j = 0; j < 3; j++, reg++)
+                       cortex_m3_dwt_addreg(target, cache->reg_list + reg,
+                                       dwt_comp + 3 * i + j);
+       }
+
+       *register_get_last_cache_p(&target->reg_cache) = cache;
+       cm3->dwt_cache = cache;
+
+       LOG_DEBUG("DWT dwtcr 0x%" PRIx32 ", comp %d, watch%s",
+                       dwtcr, cm3->dwt_num_comp,
+                       (dwtcr & (0xf << 24)) ? " only" : "/trigger");
+
+       /* REVISIT:  if num_comp > 1, check whether comparator #1 can
+        * implement single-address data value watchpoints ... so we
+        * won't need to check it later, when asked to set one up.
+        */
 }
 
-int cortex_m3_examine(struct target_s *target)
+static int cortex_m3_examine(struct target *target)
 {
        int retval;
-       uint32_t cpuid, fpcr, dwtcr, ictr;
+       uint32_t cpuid, fpcr;
        int i;
-
-       /* get pointers to arch-specific information */
-       armv7m_common_t *armv7m = target->arch_info;
-       cortex_m3_common_t *cortex_m3 = armv7m->arch_info;
-       swjdp_common_t *swjdp = &armv7m->swjdp_info;
+       struct cortex_m3_common *cortex_m3 = target_to_cm3(target);
+       struct adiv5_dap *swjdp = &cortex_m3->armv7m.dap;
 
        if ((retval = ahbap_debugport_init(swjdp)) != ERROR_OK)
                return retval;
@@ -1436,21 +1820,16 @@ int cortex_m3_examine(struct target_s *target)
                target_set_examined(target);
 
                /* Read from Device Identification Registers */
-               if ((retval = target_read_u32(target, CPUID, &cpuid)) != ERROR_OK)
+               retval = target_read_u32(target, CPUID, &cpuid);
+               if (retval != ERROR_OK)
                        return retval;
 
                if (((cpuid >> 4) & 0xc3f) == 0xc23)
-                       LOG_DEBUG("CORTEX-M3 processor detected");
+                       LOG_DEBUG("Cortex-M3 r%" PRId8 "p%" PRId8 " processor detected",
+                               (uint8_t)((cpuid >> 20) & 0xf), (uint8_t)((cpuid >> 0) & 0xf));
                LOG_DEBUG("cpuid: 0x%8.8" PRIx32 "", cpuid);
 
-               target_read_u32(target, NVIC_ICTR, &ictr);
-               cortex_m3->intlinesnum = (ictr & 0x1F) + 1;
-               cortex_m3->intsetenable = calloc(cortex_m3->intlinesnum, 4);
-               for (i = 0; i < cortex_m3->intlinesnum; i++)
-               {
-                       target_read_u32(target, NVIC_ISE0 + 4 * i, cortex_m3->intsetenable + i);
-                       LOG_DEBUG("interrupt enable[%i] = 0x%8.8" PRIx32 "", i, cortex_m3->intsetenable[i]);
-               }
+               /* NOTE: FPB and DWT are both optional. */
 
                /* Setup FPB */
                target_read_u32(target, FP_CTRL, &fpcr);
@@ -1458,7 +1837,7 @@ int cortex_m3_examine(struct target_s *target)
                cortex_m3->fp_num_code = ((fpcr >> 8) & 0x70) | ((fpcr >> 4) & 0xF); /* bits [14:12] and [7:4] */
                cortex_m3->fp_num_lit = (fpcr >> 8) & 0xF;
                cortex_m3->fp_code_available = cortex_m3->fp_num_code;
-               cortex_m3->fp_comparator_list = calloc(cortex_m3->fp_num_code + cortex_m3->fp_num_lit, sizeof(cortex_m3_fp_comparator_t));
+               cortex_m3->fp_comparator_list = calloc(cortex_m3->fp_num_code + cortex_m3->fp_num_lit, sizeof(struct cortex_m3_fp_comparator));
                cortex_m3->fpb_enabled = fpcr & 1;
                for (i = 0; i < cortex_m3->fp_num_code + cortex_m3->fp_num_lit; i++)
                {
@@ -1468,30 +1847,24 @@ int cortex_m3_examine(struct target_s *target)
                LOG_DEBUG("FPB fpcr 0x%" PRIx32 ", numcode %i, numlit %i", fpcr, cortex_m3->fp_num_code, cortex_m3->fp_num_lit);
 
                /* Setup DWT */
-               target_read_u32(target, DWT_CTRL, &dwtcr);
-               cortex_m3->dwt_num_comp = (dwtcr >> 28) & 0xF;
-               cortex_m3->dwt_comp_available = cortex_m3->dwt_num_comp;
-               cortex_m3->dwt_comparator_list = calloc(cortex_m3->dwt_num_comp, sizeof(cortex_m3_dwt_comparator_t));
-               for (i = 0; i < cortex_m3->dwt_num_comp; i++)
-               {
-                       cortex_m3->dwt_comparator_list[i].dwt_comparator_address = DWT_COMP0 + 0x10 * i;
-               }
-       }
-
-       return ERROR_OK;
-}
+               cortex_m3_dwt_setup(cortex_m3, target);
 
-int cortex_m3_quit(void)
-{
+               /* These hardware breakpoints only work for code in flash! */
+               LOG_INFO("%s: hardware has %d breakpoints, %d watchpoints",
+                               target_name(target),
+                               cortex_m3->fp_num_code,
+                               cortex_m3->dwt_num_comp);
+       }
 
        return ERROR_OK;
 }
 
-int cortex_m3_dcc_read(swjdp_common_t *swjdp, uint8_t *value, uint8_t *ctrl)
+static int cortex_m3_dcc_read(struct adiv5_dap *swjdp, uint8_t *value, uint8_t *ctrl)
 {
        uint16_t dcrdr;
+       int retval;
 
-       mem_ap_read_buf_u16( swjdp, (uint8_t*)&dcrdr, 1, DCB_DCRDR);
+       mem_ap_read_buf_u16(swjdp, (uint8_t*)&dcrdr, 1, DCB_DCRDR);
        *ctrl = (uint8_t)dcrdr;
        *value = (uint8_t)(dcrdr >> 8);
 
@@ -1502,16 +1875,19 @@ int cortex_m3_dcc_read(swjdp_common_t *swjdp, uint8_t *value, uint8_t *ctrl)
        if (dcrdr & (1 << 0))
        {
                dcrdr = 0;
-               mem_ap_write_buf_u16( swjdp, (uint8_t*)&dcrdr, 1, DCB_DCRDR);
+               retval = mem_ap_write_buf_u16(swjdp, (uint8_t*)&dcrdr, 1, DCB_DCRDR);
+               if (retval != ERROR_OK)
+                       return retval;
        }
 
        return ERROR_OK;
 }
 
-int cortex_m3_target_request_data(target_t *target, uint32_t size, uint8_t *buffer)
+static int cortex_m3_target_request_data(struct target *target,
+               uint32_t size, uint8_t *buffer)
 {
-       armv7m_common_t *armv7m = target->arch_info;
-       swjdp_common_t *swjdp = &armv7m->swjdp_info;
+       struct armv7m_common *armv7m = target_to_armv7m(target);
+       struct adiv5_dap *swjdp = &armv7m->dap;
        uint8_t data;
        uint8_t ctrl;
        uint32_t i;
@@ -1525,13 +1901,13 @@ int cortex_m3_target_request_data(target_t *target, uint32_t size, uint8_t *buff
        return ERROR_OK;
 }
 
-int cortex_m3_handle_target_request(void *priv)
+static int cortex_m3_handle_target_request(void *priv)
 {
-       target_t *target = priv;
+       struct target *target = priv;
        if (!target_was_examined(target))
                return ERROR_OK;
-       armv7m_common_t *armv7m = target->arch_info;
-       swjdp_common_t *swjdp = &armv7m->swjdp_info;
+       struct armv7m_common *armv7m = target_to_armv7m(target);
+       struct adiv5_dap *swjdp = &armv7m->dap;
 
        if (!target->dbg_msg_enabled)
                return ERROR_OK;
@@ -1563,11 +1939,11 @@ int cortex_m3_handle_target_request(void *priv)
        return ERROR_OK;
 }
 
-int cortex_m3_init_arch_info(target_t *target, cortex_m3_common_t *cortex_m3, jtag_tap_t *tap)
+static int cortex_m3_init_arch_info(struct target *target,
+               struct cortex_m3_common *cortex_m3, struct jtag_tap *tap)
 {
        int retval;
-       armv7m_common_t *armv7m;
-       armv7m = &cortex_m3->armv7m;
+       struct armv7m_common *armv7m = &cortex_m3->armv7m;
 
        armv7m_init_arch_info(target, armv7m);
 
@@ -1575,28 +1951,25 @@ int cortex_m3_init_arch_info(target_t *target, cortex_m3_common_t *cortex_m3, jt
        cortex_m3->jtag_info.tap = tap;
        cortex_m3->jtag_info.scann_size = 4;
 
-       armv7m->swjdp_info.dp_select_value = -1;
-       armv7m->swjdp_info.ap_csw_value = -1;
-       armv7m->swjdp_info.ap_tar_value = -1;
-       armv7m->swjdp_info.jtag_info = &cortex_m3->jtag_info;
-       armv7m->swjdp_info.memaccess_tck = 8;
-       armv7m->swjdp_info.tar_autoincr_block = (1 << 12);      /* Cortex-M3 has 4096 bytes autoincrement range */
+       /* default reset mode is to use srst if fitted
+        * if not it will use CORTEX_M3_RESET_VECTRESET */
+       cortex_m3->soft_reset_config = CORTEX_M3_RESET_VECTRESET;
 
-       /* initialize arch-specific breakpoint handling */
+       armv7m->arm.dap = &armv7m->dap;
 
-       cortex_m3->common_magic = CORTEX_M3_COMMON_MAGIC;
-       cortex_m3->arch_info = NULL;
+       /* Leave (only) generic DAP stuff for debugport_init(); */
+       armv7m->dap.jtag_info = &cortex_m3->jtag_info;
+       armv7m->dap.memaccess_tck = 8;
+       /* Cortex-M3 has 4096 bytes autoincrement range */
+       armv7m->dap.tar_autoincr_block = (1 << 12);
 
        /* register arch-specific functions */
        armv7m->examine_debug_reason = cortex_m3_examine_debug_reason;
 
-       armv7m->pre_debug_entry = NULL;
        armv7m->post_debug_entry = NULL;
 
        armv7m->pre_restore_context = NULL;
-       armv7m->post_restore_context = NULL;
 
-       armv7m->arch_info = cortex_m3;
        armv7m->load_core_reg_u32 = cortex_m3_load_core_reg_u32;
        armv7m->store_core_reg_u32 = cortex_m3_store_core_reg_u32;
 
@@ -1610,58 +1983,262 @@ int cortex_m3_init_arch_info(target_t *target, cortex_m3_common_t *cortex_m3, jt
        return ERROR_OK;
 }
 
-int cortex_m3_target_create(struct target_s *target, Jim_Interp *interp)
+static int cortex_m3_target_create(struct target *target, Jim_Interp *interp)
 {
-       cortex_m3_common_t *cortex_m3 = calloc(1,sizeof(cortex_m3_common_t));
+       struct cortex_m3_common *cortex_m3 = calloc(1,sizeof(struct cortex_m3_common));
 
+       cortex_m3->common_magic = CORTEX_M3_COMMON_MAGIC;
        cortex_m3_init_arch_info(target, cortex_m3, target->tap);
 
        return ERROR_OK;
 }
 
-int cortex_m3_register_commands(struct command_context_s *cmd_ctx)
+/*--------------------------------------------------------------------------*/
+
+static int cortex_m3_verify_pointer(struct command_context *cmd_ctx,
+               struct cortex_m3_common *cm3)
+{
+       if (cm3->common_magic != CORTEX_M3_COMMON_MAGIC) {
+               command_print(cmd_ctx, "target is not a Cortex-M3");
+               return ERROR_TARGET_INVALID;
+       }
+       return ERROR_OK;
+}
+
+/*
+ * Only stuff below this line should need to verify that its target
+ * is a Cortex-M3.  Everything else should have indirected through the
+ * cortexm3_target structure, which is only used with CM3 targets.
+ */
+
+static const struct {
+       char name[10];
+       unsigned mask;
+} vec_ids[] = {
+       { "hard_err",   VC_HARDERR, },
+       { "int_err",    VC_INTERR, },
+       { "bus_err",    VC_BUSERR, },
+       { "state_err",  VC_STATERR, },
+       { "chk_err",    VC_CHKERR, },
+       { "nocp_err",   VC_NOCPERR, },
+       { "mm_err",     VC_MMERR, },
+       { "reset",      VC_CORERESET, },
+};
+
+COMMAND_HANDLER(handle_cortex_m3_vector_catch_command)
 {
+       struct target *target = get_current_target(CMD_CTX);
+       struct cortex_m3_common *cortex_m3 = target_to_cm3(target);
+       struct armv7m_common *armv7m = &cortex_m3->armv7m;
+       struct adiv5_dap *swjdp = &armv7m->dap;
+       uint32_t demcr = 0;
        int retval;
-       command_t *cortex_m3_cmd;
 
-       retval = armv7m_register_commands(cmd_ctx);
+       retval = cortex_m3_verify_pointer(CMD_CTX, cortex_m3);
+       if (retval != ERROR_OK)
+               return retval;
 
-       cortex_m3_cmd = register_command(cmd_ctx, NULL, "cortex_m3", NULL, COMMAND_ANY, "cortex_m3 specific commands");
-       register_command(cmd_ctx, cortex_m3_cmd, "maskisr", handle_cortex_m3_mask_interrupts_command, COMMAND_EXEC, "mask cortex_m3 interrupts ['on'|'off']");
+       retval = mem_ap_read_atomic_u32(swjdp, DCB_DEMCR, &demcr);
+       if (retval != ERROR_OK)
+               return retval;
 
-       return retval;
+       if (CMD_ARGC > 0) {
+               unsigned catch = 0;
+
+               if (CMD_ARGC == 1) {
+                       if (strcmp(CMD_ARGV[0], "all") == 0) {
+                               catch = VC_HARDERR | VC_INTERR | VC_BUSERR
+                                       | VC_STATERR | VC_CHKERR | VC_NOCPERR
+                                       | VC_MMERR | VC_CORERESET;
+                               goto write;
+                       } else if (strcmp(CMD_ARGV[0], "none") == 0) {
+                               goto write;
+                       }
+               }
+               while (CMD_ARGC-- > 0) {
+                       unsigned i;
+                       for (i = 0; i < ARRAY_SIZE(vec_ids); i++) {
+                               if (strcmp(CMD_ARGV[CMD_ARGC], vec_ids[i].name) != 0)
+                                       continue;
+                               catch |= vec_ids[i].mask;
+                               break;
+                       }
+                       if (i == ARRAY_SIZE(vec_ids)) {
+                               LOG_ERROR("No CM3 vector '%s'", CMD_ARGV[CMD_ARGC]);
+                               return ERROR_INVALID_ARGUMENTS;
+                       }
+               }
+write:
+               /* For now, armv7m->demcr only stores vector catch flags. */
+               armv7m->demcr = catch;
+
+               demcr &= ~0xffff;
+               demcr |= catch;
+
+               /* write, but don't assume it stuck (why not??) */
+               retval = mem_ap_write_u32(swjdp, DCB_DEMCR, demcr);
+               if (retval != ERROR_OK)
+                       return retval;
+               retval = mem_ap_read_atomic_u32(swjdp, DCB_DEMCR, &demcr);
+               if (retval != ERROR_OK)
+                       return retval;
+
+               /* 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++)
+       {
+               command_print(CMD_CTX, "%9s: %s", vec_ids[i].name,
+                       (demcr & vec_ids[i].mask) ? "catch" : "ignore");
+       }
+
+       return ERROR_OK;
 }
 
-int handle_cortex_m3_mask_interrupts_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
+COMMAND_HANDLER(handle_cortex_m3_mask_interrupts_command)
 {
-       target_t *target = get_current_target(cmd_ctx);
-       armv7m_common_t *armv7m = target->arch_info;
-       cortex_m3_common_t *cortex_m3 = armv7m->arch_info;
+       struct target *target = get_current_target(CMD_CTX);
+       struct cortex_m3_common *cortex_m3 = target_to_cm3(target);
+       int retval;
+
+       retval = cortex_m3_verify_pointer(CMD_CTX, cortex_m3);
+       if (retval != ERROR_OK)
+               return retval;
 
        if (target->state != TARGET_HALTED)
        {
-               command_print(cmd_ctx, "target must be stopped for \"%s\" command", cmd);
+               command_print(CMD_CTX, "target must be stopped for \"%s\" command", CMD_NAME);
                return ERROR_OK;
        }
 
-       if (argc > 0)
+       if (CMD_ARGC > 0)
        {
-               if (!strcmp(args[0], "on"))
-               {
-                       cortex_m3_write_debug_halt_mask(target, C_HALT|C_MASKINTS, 0);
-               }
-               else if (!strcmp(args[0], "off"))
-               {
-                       cortex_m3_write_debug_halt_mask(target, C_HALT, C_MASKINTS);
-               }
-               else
-               {
-                       command_print(cmd_ctx, "usage: cortex_m3 maskisr ['on'|'off']");
-               }
+               bool enable;
+               COMMAND_PARSE_ON_OFF(CMD_ARGV[0], enable);
+               uint32_t mask_on = C_HALT | (enable ? C_MASKINTS : 0);
+               uint32_t mask_off = enable ? 0 : C_MASKINTS;
+               cortex_m3_write_debug_halt_mask(target, mask_on, mask_off);
        }
 
-       command_print(cmd_ctx, "cortex_m3 interrupt mask %s",
+       command_print(CMD_CTX, "cortex_m3 interrupt mask %s",
                        (cortex_m3->dcb_dhcsr & C_MASKINTS) ? "on" : "off");
 
        return ERROR_OK;
 }
+
+COMMAND_HANDLER(handle_cortex_m3_reset_config_command)
+{
+       struct target *target = get_current_target(CMD_CTX);
+       struct cortex_m3_common *cortex_m3 = target_to_cm3(target);
+       int retval;
+       char *reset_config;
+
+       retval = cortex_m3_verify_pointer(CMD_CTX, cortex_m3);
+       if (retval != ERROR_OK)
+               return retval;
+
+       if (CMD_ARGC > 0)
+       {
+               if (strcmp(*CMD_ARGV, "sysresetreq") == 0)
+                       cortex_m3->soft_reset_config = CORTEX_M3_RESET_SYSRESETREQ;
+               else if (strcmp(*CMD_ARGV, "vectreset") == 0)
+                       cortex_m3->soft_reset_config = CORTEX_M3_RESET_VECTRESET;
+       }
+
+       switch (cortex_m3->soft_reset_config)
+       {
+               case CORTEX_M3_RESET_SYSRESETREQ:
+                       reset_config = "sysresetreq";
+                       break;
+
+               case CORTEX_M3_RESET_VECTRESET:
+                       reset_config = "vectreset";
+                       break;
+
+               default:
+                       reset_config = "unknown";
+                       break;
+       }
+
+       command_print(CMD_CTX, "cortex_m3 reset_config %s", reset_config);
+
+       return ERROR_OK;
+}
+
+static const struct command_registration cortex_m3_exec_command_handlers[] = {
+       {
+               .name = "maskisr",
+               .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,
+               .mode = COMMAND_EXEC,
+               .help = "configure hardware vectors to trigger debug entry",
+               .usage = "['all'|'none'|('bus_err'|'chk_err'|...)*]",
+       },
+       {
+               .name = "reset_config",
+               .handler = handle_cortex_m3_reset_config_command,
+               .mode = COMMAND_ANY,
+               .help = "configure software reset handling",
+               .usage = "['srst'|'sysresetreq'|'vectreset']",
+       },
+       COMMAND_REGISTRATION_DONE
+};
+static const struct command_registration cortex_m3_command_handlers[] = {
+       {
+               .chain = armv7m_command_handlers,
+       },
+       {
+               .name = "cortex_m3",
+               .mode = COMMAND_EXEC,
+               .help = "Cortex-M3 command group",
+               .chain = cortex_m3_exec_command_handlers,
+       },
+       COMMAND_REGISTRATION_DONE
+};
+
+struct target_type cortexm3_target =
+{
+       .name = "cortex_m3",
+
+       .poll = cortex_m3_poll,
+       .arch_state = armv7m_arch_state,
+
+       .target_request_data = cortex_m3_target_request_data,
+
+       .halt = cortex_m3_halt,
+       .resume = cortex_m3_resume,
+       .step = cortex_m3_step,
+
+       .assert_reset = cortex_m3_assert_reset,
+       .deassert_reset = cortex_m3_deassert_reset,
+       .soft_reset_halt = cortex_m3_soft_reset_halt,
+
+       .get_gdb_reg_list = armv7m_get_gdb_reg_list,
+
+       .read_memory = cortex_m3_read_memory,
+       .write_memory = cortex_m3_write_memory,
+       .bulk_write_memory = cortex_m3_bulk_write_memory,
+       .checksum_memory = armv7m_checksum_memory,
+       .blank_check_memory = armv7m_blank_check_memory,
+
+       .run_algorithm = armv7m_run_algorithm,
+
+       .add_breakpoint = cortex_m3_add_breakpoint,
+       .remove_breakpoint = cortex_m3_remove_breakpoint,
+       .add_watchpoint = cortex_m3_add_watchpoint,
+       .remove_watchpoint = cortex_m3_remove_watchpoint,
+
+       .commands = cortex_m3_command_handlers,
+       .target_create = cortex_m3_target_create,
+       .init_target = cortex_m3_init_target,
+       .examine = cortex_m3_examine,
+};