]> git.sur5r.net Git - openocd/blobdiff - src/target/arm_dpm.c
target/cortex_a: remove duplicate code to read target registers
[openocd] / src / target / arm_dpm.c
index 127f87b53648c403f9ea30bdced193482eacedc5..8b99570334e259ce645962c5eeb709e9d9d7b656 100644 (file)
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the
- * Free Software Foundation, Inc.,
- * 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif
 
-#include "armv4_5.h"           /* REVISIT to become arm.h */
+#include "arm.h"
 #include "arm_dpm.h"
-#include "jtag.h"
+#include "armv8_dpm.h"
+#include <jtag/jtag.h>
 #include "register.h"
+#include "breakpoints.h"
+#include "target_type.h"
+#include "arm_opcodes.h"
 
 
 /**
  * Implements various ARM DPM operations using architectural debug registers.
  * These routines layer over core-specific communication methods to cope with
  * implementation differences between cores like ARM1136 and Cortex-A8.
+ *
+ * The "Debug Programmers' Model" (DPM) for ARMv6 and ARMv7 is defined by
+ * Part C (Debug Architecture) of the ARM Architecture Reference Manual,
+ * ARMv7-A and ARMv7-R edition (ARM DDI 0406B).  In OpenOCD, DPM operations
+ * are abstracted through internal programming interfaces to share code and
+ * to minimize needless differences in debug behavior between cores.
  */
 
+/*----------------------------------------------------------------------*/
+
 /*
  * Coprocessor support
  */
 
 /* Read coprocessor */
 static int dpm_mrc(struct target *target, int cpnum,
-               uint32_t op1, uint32_t op2, uint32_t CRn, uint32_t CRm,
-               uint32_t *value)
+       uint32_t op1, uint32_t op2, uint32_t CRn, uint32_t CRm,
+       uint32_t *value)
 {
        struct arm *arm = target_to_arm(target);
        struct arm_dpm *dpm = arm->dpm;
@@ -51,7 +61,9 @@ static int dpm_mrc(struct target *target, int cpnum,
        if (retval != ERROR_OK)
                return retval;
 
-       LOG_DEBUG("MRC p%d, %d, r0, c%d, c%d, %d", cpnum, op1, CRn, CRm, op2);
+       LOG_DEBUG("MRC p%d, %d, r0, c%d, c%d, %d", cpnum,
+               (int) op1, (int) CRn,
+               (int) CRm, (int) op2);
 
        /* read coprocessor register into R0; return via DCC */
        retval = dpm->instr_read_data_r0(dpm,
@@ -63,8 +75,8 @@ static int dpm_mrc(struct target *target, int cpnum,
 }
 
 static int dpm_mcr(struct target *target, int cpnum,
-               uint32_t op1, uint32_t op2, uint32_t CRn, uint32_t CRm,
-               uint32_t value)
+       uint32_t op1, uint32_t op2, uint32_t CRn, uint32_t CRm,
+       uint32_t value)
 {
        struct arm *arm = target_to_arm(target);
        struct arm_dpm *dpm = arm->dpm;
@@ -74,7 +86,9 @@ static int dpm_mcr(struct target *target, int cpnum,
        if (retval != ERROR_OK)
                return retval;
 
-       LOG_DEBUG("MCR p%d, %d, r0, c%d, c%d, %d", cpnum, op1, CRn, CRm, op2);
+       LOG_DEBUG("MCR p%d, %d, r0, c%d, c%d, %d", cpnum,
+               (int) op1, (int) CRn,
+               (int) CRm, (int) op2);
 
        /* read DCC into r0; then write coprocessor register from R0 */
        retval = dpm->instr_write_data_r0(dpm,
@@ -85,6 +99,8 @@ static int dpm_mcr(struct target *target, int cpnum,
        return retval;
 }
 
+/*----------------------------------------------------------------------*/
+
 /*
  * Register access utilities
  */
@@ -92,13 +108,13 @@ static int dpm_mcr(struct target *target, int cpnum,
 /* Toggles between recorded core mode (USR, SVC, etc) and a temporary one.
  * Routines *must* restore the original mode before returning!!
  */
-static int dpm_modeswitch(struct arm_dpm *dpm, enum armv4_5_mode mode)
+int arm_dpm_modeswitch(struct arm_dpm *dpm, enum arm_mode mode)
 {
        int retval;
        uint32_t cpsr;
 
        /* restore previous mode */
-       if (mode == ARMV4_5_MODE_ANY)
+       if (mode == ARM_MODE_ANY)
                cpsr = buf_get_u32(dpm->arm->cpsr->value, 0, 32);
 
        /* else force to the specified mode */
@@ -106,6 +122,8 @@ static int dpm_modeswitch(struct arm_dpm *dpm, enum armv4_5_mode mode)
                cpsr = mode;
 
        retval = dpm->instr_write_data_r0(dpm, ARMV4_5_MSR_GP(0, 0xf, 0), cpsr);
+       if (retval != ERROR_OK)
+               return retval;
 
        if (dpm->instr_cpsr_sync)
                retval = dpm->instr_cpsr_sync(dpm);
@@ -113,51 +131,98 @@ static int dpm_modeswitch(struct arm_dpm *dpm, enum armv4_5_mode mode)
        return retval;
 }
 
+/* Read 64bit VFP registers */
+static int dpm_read_reg_u64(struct arm_dpm *dpm, struct reg *r, unsigned regnum)
+{
+       int retval = ERROR_FAIL;
+       uint32_t value_r0, value_r1;
+
+       switch (regnum) {
+               case ARM_VFP_V3_D0 ... ARM_VFP_V3_D31:
+                       /* move from double word register to r0:r1: "vmov r0, r1, vm"
+                        * then read r0 via dcc
+                        */
+                       retval = dpm->instr_read_data_r0(dpm,
+                               ARMV4_5_VMOV(1, 1, 0, ((regnum - ARM_VFP_V3_D0) >> 4),
+                               ((regnum - ARM_VFP_V3_D0) & 0xf)), &value_r0);
+                       /* read r1 via dcc */
+                       retval = dpm->instr_read_data_dcc(dpm,
+                               ARMV4_5_MCR(14, 0, 1, 0, 5, 0),
+                               &value_r1);
+                       break;
+               default:
+
+                       break;
+       }
+
+       if (retval == ERROR_OK) {
+               buf_set_u32(r->value, 0, 32, value_r0);
+               buf_set_u32(r->value + 4, 0, 32, value_r1);
+               r->valid = true;
+               r->dirty = false;
+               LOG_DEBUG("READ: %s, %8.8x, %8.8x", r->name,
+                               (unsigned) value_r0, (unsigned) value_r1);
+       }
+
+       return retval;
+}
+
 /* just read the register -- rely on the core mode being right */
-static int dpm_read_reg(struct arm_dpm *dpm, struct reg *r, unsigned regnum)
+int arm_dpm_read_reg(struct arm_dpm *dpm, struct reg *r, unsigned regnum)
 {
        uint32_t value;
        int retval;
 
        switch (regnum) {
-       case 0 ... 14:
-               /* return via DCC:  "MCR p14, 0, Rnum, c0, c5, 0" */
-               retval = dpm->instr_read_data_dcc(dpm,
+               case 0 ... 14:
+                       /* return via DCC:  "MCR p14, 0, Rnum, c0, c5, 0" */
+                       retval = dpm->instr_read_data_dcc(dpm,
                                ARMV4_5_MCR(14, 0, regnum, 0, 5, 0),
                                &value);
-               break;
-       case 15:        /* PC */
-               /* "MOV r0, pc"; then return via DCC */
-               retval = dpm->instr_read_data_r0(dpm, 0xe1a0000f, &value);
-
-               /* NOTE: this seems like a slightly awkward place to update
-                * this value ... but if the PC gets written (the only way
-                * to change what we compute), the arch spec says subsequent
-                * reads return values which are "unpredictable".  So this
-                * is always right except in those broken-by-intent cases.
-                */
-               switch (dpm->arm->core_state) {
-               case ARMV4_5_STATE_ARM:
-                       value -= 8;
                        break;
-               case ARMV4_5_STATE_THUMB:
-               case ARM_STATE_THUMB_EE:
-                       value -= 4;
+               case 15:/* PC
+                        * "MOV r0, pc"; then return via DCC */
+                       retval = dpm->instr_read_data_r0(dpm, 0xe1a0000f, &value);
+
+                       /* NOTE: this seems like a slightly awkward place to update
+                        * this value ... but if the PC gets written (the only way
+                        * to change what we compute), the arch spec says subsequent
+                        * reads return values which are "unpredictable".  So this
+                        * is always right except in those broken-by-intent cases.
+                        */
+                       switch (dpm->arm->core_state) {
+                               case ARM_STATE_ARM:
+                                       value -= 8;
+                                       break;
+                               case ARM_STATE_THUMB:
+                               case ARM_STATE_THUMB_EE:
+                                       value -= 4;
+                                       break;
+                               case ARM_STATE_JAZELLE:
+                                       /* core-specific ... ? */
+                                       LOG_WARNING("Jazelle PC adjustment unknown");
+                                       break;
+                               default:
+                                       LOG_WARNING("unknow core state");
+                                       break;
+                       }
                        break;
-               case ARMV4_5_STATE_JAZELLE:
-                       /* core-specific ... ? */
-                       LOG_WARNING("Jazelle PC adjustment unknown");
+               case ARM_VFP_V3_D0 ... ARM_VFP_V3_D31:
+                       return dpm_read_reg_u64(dpm, r, regnum);
                        break;
-               }
-               break;
-       default:
-               /* 16: "MRS r0, CPSR"; then return via DCC
-                * 17: "MRS r0, SPSR"; then return via DCC
-                */
-               retval = dpm->instr_read_data_r0(dpm,
+               case ARM_VFP_V3_FPSCR:
+                       /* "VMRS r0, FPSCR"; then return via DCC */
+                       retval = dpm->instr_read_data_r0(dpm,
+                               ARMV4_5_VMRS(0), &value);
+                       break;
+               default:
+                       /* 16: "MRS r0, CPSR"; then return via DCC
+                        * 17: "MRS r0, SPSR"; then return via DCC
+                        */
+                       retval = dpm->instr_read_data_r0(dpm,
                                ARMV4_5_MRS(0, regnum & 1),
                                &value);
-               break;
+                       break;
        }
 
        if (retval == ERROR_OK) {
@@ -170,6 +235,40 @@ static int dpm_read_reg(struct arm_dpm *dpm, struct reg *r, unsigned regnum)
        return retval;
 }
 
+/* Write 64bit VFP registers */
+static int dpm_write_reg_u64(struct arm_dpm *dpm, struct reg *r, unsigned regnum)
+{
+       int retval = ERROR_FAIL;
+       uint32_t value_r0 = buf_get_u32(r->value, 0, 32);
+       uint32_t value_r1 = buf_get_u32(r->value + 4, 0, 32);
+
+       switch (regnum) {
+               case ARM_VFP_V3_D0 ... ARM_VFP_V3_D31:
+                       /* write value_r1 to r1 via dcc */
+                       retval = dpm->instr_write_data_dcc(dpm,
+                               ARMV4_5_MRC(14, 0, 1, 0, 5, 0),
+                               value_r1);
+                       /* write value_r0 to r0 via dcc then,
+                        * move to double word register from r0:r1: "vmov vm, r0, r1"
+                        */
+                       retval = dpm->instr_write_data_r0(dpm,
+                               ARMV4_5_VMOV(0, 1, 0, ((regnum - ARM_VFP_V3_D0) >> 4),
+                               ((regnum - ARM_VFP_V3_D0) & 0xf)), value_r0);
+                       break;
+               default:
+
+                       break;
+       }
+
+       if (retval == ERROR_OK) {
+               r->dirty = false;
+               LOG_DEBUG("WRITE: %s, %8.8x, %8.8x", r->name,
+                               (unsigned) value_r0, (unsigned) value_r1);
+       }
+
+       return retval;
+}
+
 /* just write the register -- rely on the core mode being right */
 static int dpm_write_reg(struct arm_dpm *dpm, struct reg *r, unsigned regnum)
 {
@@ -177,28 +276,38 @@ static int dpm_write_reg(struct arm_dpm *dpm, struct reg *r, unsigned regnum)
        uint32_t value = buf_get_u32(r->value, 0, 32);
 
        switch (regnum) {
-       case 0 ... 14:
-               /* load register from DCC:  "MCR p14, 0, Rnum, c0, c5, 0" */
-               retval = dpm->instr_write_data_dcc(dpm,
+               case 0 ... 14:
+                       /* load register from DCC:  "MRC p14, 0, Rnum, c0, c5, 0" */
+                       retval = dpm->instr_write_data_dcc(dpm,
                                ARMV4_5_MRC(14, 0, regnum, 0, 5, 0),
                                value);
-               break;
-       case 15:        /* PC */
-               /* read r0 from DCC; then "MOV pc, r0" */
-               retval = dpm->instr_write_data_r0(dpm, 0xe1a0f000, value);
-               break;
-       default:
-               /* 16: read r0 from DCC, then "MSR r0, CPSR_cxsf"
-                * 17: read r0 from DCC, then "MSR r0, SPSR_cxsf"
-                */
-               retval = dpm->instr_write_data_r0(dpm,
+                       break;
+               case 15:/* PC
+                        * read r0 from DCC; then "MOV pc, r0" */
+                       retval = dpm->instr_write_data_r0(dpm, 0xe1a0f000, value);
+                       break;
+               case ARM_VFP_V3_D0 ... ARM_VFP_V3_D31:
+                       return dpm_write_reg_u64(dpm, r, regnum);
+                       break;
+               case ARM_VFP_V3_FPSCR:
+                       /* move to r0 from DCC, then "VMSR FPSCR, r0" */
+                       retval = dpm->instr_write_data_r0(dpm,
+                               ARMV4_5_VMSR(0), value);
+                       break;
+               default:
+                       /* 16: read r0 from DCC, then "MSR r0, CPSR_cxsf"
+                        * 17: read r0 from DCC, then "MSR r0, SPSR_cxsf"
+                        */
+                       retval = dpm->instr_write_data_r0(dpm,
                                ARMV4_5_MSR_GP(0, 0xf, regnum & 1),
                                value);
+                       if (retval != ERROR_OK)
+                               return retval;
 
-               if (regnum == 16 && dpm->instr_cpsr_sync)
-                       retval = dpm->instr_cpsr_sync(dpm);
+                       if (regnum == 16 && dpm->instr_cpsr_sync)
+                               retval = dpm->instr_cpsr_sync(dpm);
 
-               break;
+                       break;
        }
 
        if (retval == ERROR_OK) {
@@ -209,6 +318,18 @@ static int dpm_write_reg(struct arm_dpm *dpm, struct reg *r, unsigned regnum)
        return retval;
 }
 
+/**
+ * Write to program counter and switch the core state (arm/thumb) according to
+ * the address.
+ */
+static int dpm_write_pc_core_state(struct arm_dpm *dpm, struct reg *r)
+{
+       uint32_t value = buf_get_u32(r->value, 0, 32);
+
+       /* read r0 from DCC; then "BX r0" */
+       return dpm->instr_write_data_r0(dpm, ARMV4_5_BX(0), value);
+}
+
 /**
  * Read basic registers of the the current context:  R0 to R15, and CPSR;
  * sets the core mode (such as USR or IRQ) and state (such as ARM or Thumb).
@@ -227,14 +348,16 @@ int arm_dpm_read_current_registers(struct arm_dpm *dpm)
        if (retval != ERROR_OK)
                return retval;
 
-       /* read R0 first (it's used for scratch), then CPSR */
-       r = arm->core_cache->reg_list + 0;
-       if (!r->valid) {
-               retval = dpm_read_reg(dpm, r, 0);
-               if (retval != ERROR_OK)
-                       goto fail;
+       /* read R0 and R1 first (it's used for scratch), then CPSR */
+       for (unsigned i = 0; i < 2; i++) {
+               r = arm->core_cache->reg_list + i;
+               if (!r->valid) {
+                       retval = arm_dpm_read_reg(dpm, r, i);
+                       if (retval != ERROR_OK)
+                               goto fail;
+               }
+               r->dirty = true;
        }
-       r->dirty = true;
 
        retval = dpm->instr_read_data_r0(dpm, ARMV4_5_MRS(0, 0), &cpsr);
        if (retval != ERROR_OK)
@@ -244,28 +367,85 @@ int arm_dpm_read_current_registers(struct arm_dpm *dpm)
        arm_set_cpsr(arm, cpsr);
 
        /* REVISIT we can probably avoid reading R1..R14, saving time... */
-       for (unsigned i = 1; i < 16; i++) {
+       for (unsigned i = 2; i < 16; i++) {
                r = arm_reg_current(arm, i);
                if (r->valid)
                        continue;
 
-               retval = dpm_read_reg(dpm, r, i);
+               retval = arm_dpm_read_reg(dpm, r, i);
                if (retval != ERROR_OK)
                        goto fail;
        }
 
        /* NOTE: SPSR ignored (if it's even relevant). */
 
+       /* REVISIT the debugger can trigger various exceptions.  See the
+        * ARMv7A architecture spec, section C5.7, for more info about
+        * what defenses are needed; v6 debug has the most issues.
+        */
+
 fail:
        /* (void) */ dpm->finish(dpm);
        return retval;
 }
 
+/* Avoid needless I/O ... leave breakpoints and watchpoints alone
+ * unless they're removed, or need updating because of single-stepping
+ * or running debugger code.
+ */
+static int dpm_maybe_update_bpwp(struct arm_dpm *dpm, bool bpwp,
+       struct dpm_bpwp *xp, int *set_p)
+{
+       int retval = ERROR_OK;
+       bool disable;
+
+       if (!set_p) {
+               if (!xp->dirty)
+                       goto done;
+               xp->dirty = false;
+               /* removed or startup; we must disable it */
+               disable = true;
+       } else if (bpwp) {
+               if (!xp->dirty)
+                       goto done;
+               /* disabled, but we must set it */
+               xp->dirty = disable = false;
+               *set_p = true;
+       } else {
+               if (!*set_p)
+                       goto done;
+               /* set, but we must temporarily disable it */
+               xp->dirty = disable = true;
+               *set_p = false;
+       }
+
+       if (disable)
+               retval = dpm->bpwp_disable(dpm, xp->number);
+       else
+               retval = dpm->bpwp_enable(dpm, xp->number,
+                               xp->address, xp->control);
+
+       if (retval != ERROR_OK)
+               LOG_ERROR("%s: can't %s HW %spoint %d",
+                       disable ? "disable" : "enable",
+                       target_name(dpm->arm->target),
+                       (xp->number < 16) ? "break" : "watch",
+                       xp->number & 0xf);
+done:
+       return retval;
+}
+
+static int dpm_add_breakpoint(struct target *target, struct breakpoint *bp);
+
 /**
  * Writes all modified core registers for all processor modes.  In normal
  * operation this is called on exit from halting debug state.
+ *
+ * @param dpm: represents the processor
+ * @param bpwp: true ensures breakpoints and watchpoints are set,
+ *     false ensures they are cleared
  */
-int arm_dpm_write_dirty_registers(struct arm_dpm *dpm)
+int arm_dpm_write_dirty_registers(struct arm_dpm *dpm, bool bpwp)
 {
        struct arm *arm = dpm->arm;
        struct reg_cache *cache = arm->core_cache;
@@ -276,18 +456,52 @@ int arm_dpm_write_dirty_registers(struct arm_dpm *dpm)
        if (retval != ERROR_OK)
                goto done;
 
+       /* If we're managing hardware breakpoints for this core, enable
+        * or disable them as requested.
+        *
+        * REVISIT We don't yet manage them for ANY cores.  Eventually
+        * we should be able to assume we handle them; but until then,
+        * cope with the hand-crafted breakpoint code.
+        */
+       if (arm->target->type->add_breakpoint == dpm_add_breakpoint) {
+               for (unsigned i = 0; i < dpm->nbp; i++) {
+                       struct dpm_bp *dbp = dpm->dbp + i;
+                       struct breakpoint *bp = dbp->bp;
+
+                       retval = dpm_maybe_update_bpwp(dpm, bpwp, &dbp->bpwp,
+                                       bp ? &bp->set : NULL);
+                       if (retval != ERROR_OK)
+                               goto done;
+               }
+       }
+
+       /* enable/disable watchpoints */
+       for (unsigned i = 0; i < dpm->nwp; i++) {
+               struct dpm_wp *dwp = dpm->dwp + i;
+               struct watchpoint *wp = dwp->wp;
+
+               retval = dpm_maybe_update_bpwp(dpm, bpwp, &dwp->bpwp,
+                               wp ? &wp->set : NULL);
+               if (retval != ERROR_OK)
+                       goto done;
+       }
+
+       /* NOTE:  writes to breakpoint and watchpoint registers might
+        * be queued, and need (efficient/batched) flushing later.
+        */
+
        /* Scan the registers until we find one that's both dirty and
         * eligible for flushing.  Flush that and everything else that
         * shares the same core mode setting.  Typically this won't
         * actually find anything to do...
         */
        do {
-               enum armv4_5_mode mode = ARMV4_5_MODE_ANY;
+               enum arm_mode mode = ARM_MODE_ANY;
 
                did_write = false;
 
-               /* check everything except our scratch register R0 */
-               for (unsigned i = 1; i < cache->num_regs; i++) {
+               /* check everything except our scratch registers R0 and R1 */
+               for (unsigned i = 2; i < cache->num_regs; i++) {
                        struct arm_reg *r;
                        unsigned regnum;
 
@@ -304,7 +518,7 @@ int arm_dpm_write_dirty_registers(struct arm_dpm *dpm)
 
                        /* may need to pick and set a mode */
                        if (!did_write) {
-                               enum armv4_5_mode tmode;
+                               enum arm_mode tmode;
 
                                did_write = true;
                                mode = tmode = r->mode;
@@ -316,10 +530,10 @@ int arm_dpm_write_dirty_registers(struct arm_dpm *dpm)
                                         * we "know" core mode is accurate
                                         * since we haven't changed it yet
                                         */
-                                       if (arm->core_mode == ARMV4_5_MODE_FIQ
-                                                       && ARMV4_5_MODE_ANY
-                                                               != mode)
-                                               tmode = ARMV4_5_MODE_USR;
+                                       if (arm->core_mode == ARM_MODE_FIQ
+                                           && ARM_MODE_ANY
+                                           != mode)
+                                               tmode = ARM_MODE_USR;
                                        break;
                                case 16:
                                        /* SPSR */
@@ -328,16 +542,20 @@ int arm_dpm_write_dirty_registers(struct arm_dpm *dpm)
                                }
 
                                /* REVISIT error checks */
-                               if (tmode != ARMV4_5_MODE_ANY)
-                                       retval = dpm_modeswitch(dpm, tmode);
+                               if (tmode != ARM_MODE_ANY) {
+                                       retval = arm_dpm_modeswitch(dpm, tmode);
+                                       if (retval != ERROR_OK)
+                                               goto done;
+                               }
                        }
                        if (r->mode != mode)
                                continue;
 
                        retval = dpm_write_reg(dpm,
-                                       &cache->reg_list[i],
-                                       regnum);
-
+                                              &cache->reg_list[i],
+                                              regnum);
+                       if (retval != ERROR_OK)
+                               goto done;
                }
 
        } while (did_write);
@@ -346,70 +564,100 @@ int arm_dpm_write_dirty_registers(struct arm_dpm *dpm)
         * or it's dirty.  Must write PC to ensure the return address is
         * defined, and must not write it before CPSR.
         */
-       retval = dpm_modeswitch(dpm, ARMV4_5_MODE_ANY);
+       retval = arm_dpm_modeswitch(dpm, ARM_MODE_ANY);
+       if (retval != ERROR_OK)
+               goto done;
        arm->cpsr->dirty = false;
 
-       retval = dpm_write_reg(dpm, &cache->reg_list[15], 15);
-       cache->reg_list[15].dirty = false;
+       /* restore the PC, make sure to also switch the core state
+        * to whatever it was set to with "arm core_state" command.
+        * target code will have set PC to an appropriate resume address.
+        */
+       retval = dpm_write_pc_core_state(dpm, arm->pc);
+       if (retval != ERROR_OK)
+               goto done;
+       /* on Cortex-A5 (as found on NXP VF610 SoC), BX instruction
+        * executed in debug state doesn't appear to set the PC,
+        * explicitly set it with a "MOV pc, r0". This doesn't influence
+        * CPSR on Cortex-A9 so it should be OK. Maybe due to different
+        * debug version?
+        */
+       retval = dpm_write_reg(dpm, arm->pc, 15);
+       if (retval != ERROR_OK)
+               goto done;
+       arm->pc->dirty = false;
 
-       /* flush R0 -- it's *very* dirty by now */
-       retval = dpm_write_reg(dpm, &cache->reg_list[0], 0);
-       cache->reg_list[0].dirty = false;
+       /* flush R0 and R1 (our scratch registers) */
+       for (unsigned i = 0; i < 2; i++) {
+               retval = dpm_write_reg(dpm, &cache->reg_list[i], i);
+               if (retval != ERROR_OK)
+                       goto done;
+               cache->reg_list[i].dirty = false;
+       }
 
        /* (void) */ dpm->finish(dpm);
 done:
        return retval;
 }
 
-/* Returns ARMV4_5_MODE_ANY or temporary mode to use while reading the
+/* Returns ARM_MODE_ANY or temporary mode to use while reading the
  * specified register ... works around flakiness from ARM core calls.
  * Caller already filtered out SPSR access; mode is never MODE_SYS
  * or MODE_ANY.
  */
-static enum armv4_5_mode dpm_mapmode(struct arm *arm,
-               unsigned num, enum armv4_5_mode mode)
+static enum arm_mode dpm_mapmode(struct arm *arm,
+       unsigned num, enum arm_mode mode)
 {
-       enum armv4_5_mode amode = arm->core_mode;
+       enum arm_mode amode = arm->core_mode;
 
        /* don't switch if the mode is already correct */
-       if (amode == ARMV4_5_MODE_SYS)
-                amode = ARMV4_5_MODE_USR;
+       if (amode == ARM_MODE_SYS)
+               amode = ARM_MODE_USR;
        if (mode == amode)
-               return ARMV4_5_MODE_ANY;
+               return ARM_MODE_ANY;
 
        switch (num) {
-       /* don't switch for non-shadowed registers (r0..r7, r15/pc, cpsr) */
-       case 0 ... 7:
-       case 15:
-       case 16:
-               break;
-       /* r8..r12 aren't shadowed for anything except FIQ */
-       case 8 ... 12:
-               if (mode == ARMV4_5_MODE_FIQ)
+               /* don't switch for non-shadowed registers (r0..r7, r15/pc, cpsr) */
+               case 0 ... 7:
+               case 15:
+               case 16:
+                       break;
+               /* r8..r12 aren't shadowed for anything except FIQ */
+               case 8 ... 12:
+                       if (mode == ARM_MODE_FIQ)
+                               return mode;
+                       break;
+               /* r13/sp, and r14/lr are always shadowed */
+               case 13:
+               case 14:
+               case ARM_VFP_V3_D0 ... ARM_VFP_V3_FPSCR:
                        return mode;
-               break;
-       /* r13/sp, and r14/lr are always shadowed */
-       case 13:
-       case 14:
-               return mode;
-       default:
-               LOG_WARNING("invalid register #%u", num);
-               break;
+               default:
+                       LOG_WARNING("invalid register #%u", num);
+                       break;
        }
-       return ARMV4_5_MODE_ANY;
+       return ARM_MODE_ANY;
 }
 
+
+/*
+ * Standard ARM register accessors ... there are three methods
+ * in "struct arm", to support individual read/write and bulk read
+ * of registers.
+ */
+
 static int arm_dpm_read_core_reg(struct target *target, struct reg *r,
-               int regnum, enum armv4_5_mode mode)
+       int regnum, enum arm_mode mode)
 {
        struct arm_dpm *dpm = target_to_arm(target)->dpm;
        int retval;
 
-       if (regnum < 0 || regnum > 16)
-               return ERROR_INVALID_ARGUMENTS;
+       if (regnum < 0 || (regnum > 16 && regnum < ARM_VFP_V3_D0) ||
+               (regnum > ARM_VFP_V3_FPSCR))
+               return ERROR_COMMAND_SYNTAX_ERROR;
 
        if (regnum == 16) {
-               if (mode != ARMV4_5_MODE_ANY)
+               if (mode != ARM_MODE_ANY)
                        regnum = 17;
        } else
                mode = dpm_mapmode(dpm->arm, regnum, mode);
@@ -422,17 +670,19 @@ static int arm_dpm_read_core_reg(struct target *target, struct reg *r,
        if (retval != ERROR_OK)
                return retval;
 
-       if (mode != ARMV4_5_MODE_ANY) {
-               retval = dpm_modeswitch(dpm, mode);
+       if (mode != ARM_MODE_ANY) {
+               retval = arm_dpm_modeswitch(dpm, mode);
                if (retval != ERROR_OK)
                        goto fail;
        }
 
-       retval = dpm_read_reg(dpm, r, regnum);
+       retval = arm_dpm_read_reg(dpm, r, regnum);
+       if (retval != ERROR_OK)
+               goto fail;
        /* always clean up, regardless of error */
 
-       if (mode != ARMV4_5_MODE_ANY)
-               /* (void) */ dpm_modeswitch(dpm, ARMV4_5_MODE_ANY);
+       if (mode != ARM_MODE_ANY)
+               /* (void) */ arm_dpm_modeswitch(dpm, ARM_MODE_ANY);
 
 fail:
        /* (void) */ dpm->finish(dpm);
@@ -440,17 +690,18 @@ fail:
 }
 
 static int arm_dpm_write_core_reg(struct target *target, struct reg *r,
-               int regnum, enum armv4_5_mode mode, uint32_t value)
+       int regnum, enum arm_mode mode, uint8_t *value)
 {
        struct arm_dpm *dpm = target_to_arm(target)->dpm;
        int retval;
 
 
-       if (regnum < 0 || regnum > 16)
-               return ERROR_INVALID_ARGUMENTS;
+       if (regnum < 0 || (regnum > 16 && regnum < ARM_VFP_V3_D0) ||
+                       (regnum > ARM_VFP_V3_FPSCR))
+               return ERROR_COMMAND_SYNTAX_ERROR;
 
        if (regnum == 16) {
-               if (mode != ARMV4_5_MODE_ANY)
+               if (mode != ARM_MODE_ANY)
                        regnum = 17;
        } else
                mode = dpm_mapmode(dpm->arm, regnum, mode);
@@ -463,8 +714,8 @@ static int arm_dpm_write_core_reg(struct target *target, struct reg *r,
        if (retval != ERROR_OK)
                return retval;
 
-       if (mode != ARMV4_5_MODE_ANY) {
-               retval = dpm_modeswitch(dpm, mode);
+       if (mode != ARM_MODE_ANY) {
+               retval = arm_dpm_modeswitch(dpm, mode);
                if (retval != ERROR_OK)
                        goto fail;
        }
@@ -472,8 +723,8 @@ static int arm_dpm_write_core_reg(struct target *target, struct reg *r,
        retval = dpm_write_reg(dpm, r, regnum);
        /* always clean up, regardless of error */
 
-       if (mode != ARMV4_5_MODE_ANY)
-               /* (void) */ dpm_modeswitch(dpm, ARMV4_5_MODE_ANY);
+       if (mode != ARM_MODE_ANY)
+               /* (void) */ arm_dpm_modeswitch(dpm, ARM_MODE_ANY);
 
 fail:
        /* (void) */ dpm->finish(dpm);
@@ -493,7 +744,7 @@ static int arm_dpm_full_context(struct target *target)
                goto done;
 
        do {
-               enum armv4_5_mode mode = ARMV4_5_MODE_ANY;
+               enum arm_mode mode = ARM_MODE_ANY;
 
                did_read = false;
 
@@ -517,58 +768,346 @@ static int arm_dpm_full_context(struct target *target)
                                did_read = true;
                                mode = r->mode;
 
-                               /* For R8..R12 when we've entered debug
-                                * state in FIQ mode... patch mode.
+                               /* For regular (ARM_MODE_ANY) R8..R12
+                                * in case we've entered debug state
+                                * in FIQ mode we need to patch mode.
                                 */
-                               if (mode == ARMV4_5_MODE_ANY)
-                                       mode = ARMV4_5_MODE_USR;
+                               if (mode != ARM_MODE_ANY)
+                                       retval = arm_dpm_modeswitch(dpm, mode);
+                               else
+                                       retval = arm_dpm_modeswitch(dpm, ARM_MODE_USR);
 
-                               /* REVISIT error checks */
-                               retval = dpm_modeswitch(dpm, mode);
+                               if (retval != ERROR_OK)
+                                       goto done;
                        }
                        if (r->mode != mode)
                                continue;
 
                        /* CPSR was read, so "R16" must mean SPSR */
-                       retval = dpm_read_reg(dpm,
+                       retval = arm_dpm_read_reg(dpm,
                                        &cache->reg_list[i],
                                        (r->num == 16) ? 17 : r->num);
-
+                       if (retval != ERROR_OK)
+                               goto done;
                }
 
        } while (did_read);
 
-       retval = dpm_modeswitch(dpm, ARMV4_5_MODE_ANY);
+       retval = arm_dpm_modeswitch(dpm, ARM_MODE_ANY);
        /* (void) */ dpm->finish(dpm);
 done:
        return retval;
 }
 
+
+/*----------------------------------------------------------------------*/
+
+/*
+ * Breakpoint and Watchpoint support.
+ *
+ * Hardware {break,watch}points are usually left active, to minimize
+ * debug entry/exit costs.  When they are set or cleared, it's done in
+ * batches.  Also, DPM-conformant hardware can update debug registers
+ * regardless of whether the CPU is running or halted ... though that
+ * fact isn't currently leveraged.
+ */
+
+static int dpm_bpwp_setup(struct arm_dpm *dpm, struct dpm_bpwp *xp,
+       uint32_t addr, uint32_t length)
+{
+       uint32_t control;
+
+       control = (1 << 0)      /* enable */
+               | (3 << 1);     /* both user and privileged access */
+
+       /* Match 1, 2, or all 4 byte addresses in this word.
+        *
+        * FIXME:  v7 hardware allows lengths up to 2 GB for BP and WP.
+        * Support larger length, when addr is suitably aligned.  In
+        * particular, allow watchpoints on 8 byte "double" values.
+        *
+        * REVISIT allow watchpoints on unaligned 2-bit values; and on
+        * v7 hardware, unaligned 4-byte ones too.
+        */
+       switch (length) {
+               case 1:
+                       control |= (1 << (addr & 3)) << 5;
+                       break;
+               case 2:
+                       /* require 2-byte alignment */
+                       if (!(addr & 1)) {
+                               control |= (3 << (addr & 2)) << 5;
+                               break;
+                       }
+               /* FALL THROUGH */
+               case 4:
+                       /* require 4-byte alignment */
+                       if (!(addr & 3)) {
+                               control |= 0xf << 5;
+                               break;
+                       }
+               /* FALL THROUGH */
+               default:
+                       LOG_ERROR("unsupported {break,watch}point length/alignment");
+                       return ERROR_COMMAND_SYNTAX_ERROR;
+       }
+
+       /* other shared control bits:
+        * bits 15:14 == 0 ... both secure and nonsecure states (v6.1+ only)
+        * bit 20 == 0 ... not linked to a context ID
+        * bit 28:24 == 0 ... not ignoring N LSBs (v7 only)
+        */
+
+       xp->address = addr & ~3;
+       xp->control = control;
+       xp->dirty = true;
+
+       LOG_DEBUG("BPWP: addr %8.8" PRIx32 ", control %" PRIx32 ", number %d",
+               xp->address, control, xp->number);
+
+       /* hardware is updated in write_dirty_registers() */
+       return ERROR_OK;
+}
+
+static int dpm_add_breakpoint(struct target *target, struct breakpoint *bp)
+{
+       struct arm *arm = target_to_arm(target);
+       struct arm_dpm *dpm = arm->dpm;
+       int retval = ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
+
+       if (bp->length < 2)
+               return ERROR_COMMAND_SYNTAX_ERROR;
+       if (!dpm->bpwp_enable)
+               return retval;
+
+       /* FIXME we need a generic solution for software breakpoints. */
+       if (bp->type == BKPT_SOFT)
+               LOG_DEBUG("using HW bkpt, not SW...");
+
+       for (unsigned i = 0; i < dpm->nbp; i++) {
+               if (!dpm->dbp[i].bp) {
+                       retval = dpm_bpwp_setup(dpm, &dpm->dbp[i].bpwp,
+                                       bp->address, bp->length);
+                       if (retval == ERROR_OK)
+                               dpm->dbp[i].bp = bp;
+                       break;
+               }
+       }
+
+       return retval;
+}
+
+static int dpm_remove_breakpoint(struct target *target, struct breakpoint *bp)
+{
+       struct arm *arm = target_to_arm(target);
+       struct arm_dpm *dpm = arm->dpm;
+       int retval = ERROR_COMMAND_SYNTAX_ERROR;
+
+       for (unsigned i = 0; i < dpm->nbp; i++) {
+               if (dpm->dbp[i].bp == bp) {
+                       dpm->dbp[i].bp = NULL;
+                       dpm->dbp[i].bpwp.dirty = true;
+
+                       /* hardware is updated in write_dirty_registers() */
+                       retval = ERROR_OK;
+                       break;
+               }
+       }
+
+       return retval;
+}
+
+static int dpm_watchpoint_setup(struct arm_dpm *dpm, unsigned index_t,
+       struct watchpoint *wp)
+{
+       int retval;
+       struct dpm_wp *dwp = dpm->dwp + index_t;
+       uint32_t control;
+
+       /* this hardware doesn't support data value matching or masking */
+       if (wp->value || wp->mask != ~(uint32_t)0) {
+               LOG_DEBUG("watchpoint values and masking not supported");
+               return ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
+       }
+
+       retval = dpm_bpwp_setup(dpm, &dwp->bpwp, wp->address, wp->length);
+       if (retval != ERROR_OK)
+               return retval;
+
+       control = dwp->bpwp.control;
+       switch (wp->rw) {
+               case WPT_READ:
+                       control |= 1 << 3;
+                       break;
+               case WPT_WRITE:
+                       control |= 2 << 3;
+                       break;
+               case WPT_ACCESS:
+                       control |= 3 << 3;
+                       break;
+       }
+       dwp->bpwp.control = control;
+
+       dpm->dwp[index_t].wp = wp;
+
+       return retval;
+}
+
+static int dpm_add_watchpoint(struct target *target, struct watchpoint *wp)
+{
+       struct arm *arm = target_to_arm(target);
+       struct arm_dpm *dpm = arm->dpm;
+       int retval = ERROR_TARGET_RESOURCE_NOT_AVAILABLE;
+
+       if (dpm->bpwp_enable) {
+               for (unsigned i = 0; i < dpm->nwp; i++) {
+                       if (!dpm->dwp[i].wp) {
+                               retval = dpm_watchpoint_setup(dpm, i, wp);
+                               break;
+                       }
+               }
+       }
+
+       return retval;
+}
+
+static int dpm_remove_watchpoint(struct target *target, struct watchpoint *wp)
+{
+       struct arm *arm = target_to_arm(target);
+       struct arm_dpm *dpm = arm->dpm;
+       int retval = ERROR_COMMAND_SYNTAX_ERROR;
+
+       for (unsigned i = 0; i < dpm->nwp; i++) {
+               if (dpm->dwp[i].wp == wp) {
+                       dpm->dwp[i].wp = NULL;
+                       dpm->dwp[i].bpwp.dirty = true;
+
+                       /* hardware is updated in write_dirty_registers() */
+                       retval = ERROR_OK;
+                       break;
+               }
+       }
+
+       return retval;
+}
+
+void arm_dpm_report_wfar(struct arm_dpm *dpm, uint32_t addr)
+{
+       switch (dpm->arm->core_state) {
+               case ARM_STATE_ARM:
+                       addr -= 8;
+                       break;
+               case ARM_STATE_THUMB:
+               case ARM_STATE_THUMB_EE:
+                       addr -= 4;
+                       break;
+               case ARM_STATE_JAZELLE:
+               case ARM_STATE_AARCH64:
+                       /* ?? */
+                       break;
+       }
+       dpm->wp_pc = addr;
+}
+
+/*----------------------------------------------------------------------*/
+
+/*
+ * Other debug and support utilities
+ */
+
+void arm_dpm_report_dscr(struct arm_dpm *dpm, uint32_t dscr)
+{
+       struct target *target = dpm->arm->target;
+
+       dpm->dscr = dscr;
+
+       /* Examine debug reason */
+       switch (DSCR_ENTRY(dscr)) {
+               case DSCR_ENTRY_HALT_REQ:       /* HALT request from debugger */
+               case DSCR_ENTRY_EXT_DBG_REQ:    /* EDBGRQ */
+                       target->debug_reason = DBG_REASON_DBGRQ;
+                       break;
+               case DSCR_ENTRY_BREAKPOINT:     /* HW breakpoint */
+               case DSCR_ENTRY_BKPT_INSTR:     /* vector catch */
+                       target->debug_reason = DBG_REASON_BREAKPOINT;
+                       break;
+               case DSCR_ENTRY_IMPRECISE_WATCHPT:      /* asynch watchpoint */
+               case DSCR_ENTRY_PRECISE_WATCHPT:/* precise watchpoint */
+                       target->debug_reason = DBG_REASON_WATCHPOINT;
+                       break;
+               default:
+                       target->debug_reason = DBG_REASON_UNDEFINED;
+                       break;
+       }
+}
+
+/*----------------------------------------------------------------------*/
+
+/*
+ * Setup and management support.
+ */
+
 /**
  * Hooks up this DPM to its associated target; call only once.
  * Initially this only covers the register cache.
+ *
+ * Oh, and watchpoints.  Yeah.
  */
 int arm_dpm_setup(struct arm_dpm *dpm)
 {
        struct arm *arm = dpm->arm;
        struct target *target = arm->target;
-       struct reg_cache *cache;
+       struct reg_cache *cache = 0;
 
        arm->dpm = dpm;
 
+       /* register access setup */
        arm->full_context = arm_dpm_full_context;
        arm->read_core_reg = arm_dpm_read_core_reg;
        arm->write_core_reg = arm_dpm_write_core_reg;
 
-       cache = armv4_5_build_reg_cache(target, arm);
-       if (!cache)
-               return ERROR_FAIL;
+       if (arm->core_cache == NULL) {
+               cache = arm_build_reg_cache(target, arm);
+               if (!cache)
+                       return ERROR_FAIL;
 
-       *register_get_last_cache_p(&target->reg_cache) = cache;
+               *register_get_last_cache_p(&target->reg_cache) = cache;
+       }
 
+       /* coprocessor access setup */
        arm->mrc = dpm_mrc;
        arm->mcr = dpm_mcr;
 
+       /* breakpoint setup -- optional until it works everywhere */
+       if (!target->type->add_breakpoint) {
+               target->type->add_breakpoint = dpm_add_breakpoint;
+               target->type->remove_breakpoint = dpm_remove_breakpoint;
+       }
+
+       /* watchpoint setup */
+       target->type->add_watchpoint = dpm_add_watchpoint;
+       target->type->remove_watchpoint = dpm_remove_watchpoint;
+
+       /* FIXME add vector catch support */
+
+       dpm->nbp = 1 + ((dpm->didr >> 24) & 0xf);
+       dpm->nwp = 1 + ((dpm->didr >> 28) & 0xf);
+       dpm->dbp = calloc(dpm->nbp, sizeof *dpm->dbp);
+       dpm->dwp = calloc(dpm->nwp, sizeof *dpm->dwp);
+
+       if (!dpm->dbp || !dpm->dwp) {
+               free(dpm->dbp);
+               free(dpm->dwp);
+               return ERROR_FAIL;
+       }
+
+       LOG_INFO("%s: hardware has %d breakpoints, %d watchpoints",
+               target_name(target), dpm->nbp, dpm->nwp);
+
+       /* REVISIT ... and some of those breakpoints could match
+        * execution context IDs...
+        */
+
        return ERROR_OK;
 }
 
@@ -578,6 +1117,21 @@ int arm_dpm_setup(struct arm_dpm *dpm)
  */
 int arm_dpm_initialize(struct arm_dpm *dpm)
 {
-       /* FIXME -- nothing yet */
+       /* Disable all breakpoints and watchpoints at startup. */
+       if (dpm->bpwp_disable) {
+               unsigned i;
+
+               for (i = 0; i < dpm->nbp; i++) {
+                       dpm->dbp[i].bpwp.number = i;
+                       (void) dpm->bpwp_disable(dpm, i);
+               }
+               for (i = 0; i < dpm->nwp; i++) {
+                       dpm->dwp[i].bpwp.number = 16 + i;
+                       (void) dpm->bpwp_disable(dpm, 16 + i);
+               }
+       } else
+               LOG_WARNING("%s: can't disable breakpoints and watchpoints",
+                       target_name(dpm->arm->target));
+
        return ERROR_OK;
 }