ARM: keep a handle to the PC

Keep a handle to the PC in "struct arm", and use it.
This register is used a fair amount, so this is a net
minor code shrink (other than some line length fixes),
but mostly it's to make things more readable.

For XScale, fix a dodgy sequence while stepping.  It
was initializing a variable to a non-NULL value, then
updating it to handle the step-over-active-breakpoint
case, and then later testing for non-NULL to see if
it should reverse that step-over-active logic.  It
should have done like ARM7/ARM9 does: init to NULL.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>

16 files changed, 106 insertions, 88 deletions

diff --git a/src/target/arm.h b/src/target/arm.h
index c72b1942..6b304e9f 100644
--- a/src/target/arm.h
+++ b/src/target/arm.h
@@ -95,6 +95,9 @@ struct arm {
 	int common_magic;
 	struct reg_cache *core_cache;
 
+	/** Handle to the PC; valid in all core modes. */
+	struct reg *pc;
+
 	/** Handle to the CPSR; valid in all core modes. */
 	struct reg *cpsr;
 
diff --git a/src/target/arm11.c b/src/target/arm11.c
index 678d8ac6..51be7018 100644
--- a/src/target/arm11.c
+++ b/src/target/arm11.c
@@ -451,7 +451,7 @@ static int arm11_halt(struct target *target)
 static uint32_t
 arm11_nextpc(struct arm11_common *arm11, int current, uint32_t address)
 {
-	void *value = arm11->arm.core_cache->reg_list[15].value;
+	void *value = arm11->arm.pc->value;
 
 	if (!current)
 		buf_set_u32(value, 0, 32, address);
diff --git a/src/target/arm720t.c b/src/target/arm720t.c
index efafa5ee..2275935d 100644
--- a/src/target/arm720t.c
+++ b/src/target/arm720t.c
@@ -361,9 +361,9 @@ static int arm720t_soft_reset_halt(struct target *target)
 	armv4_5->cpsr->dirty = 1;
 
 	/* start fetching from 0x0 */
-	buf_set_u32(armv4_5->core_cache->reg_list[15].value, 0, 32, 0x0);
-	armv4_5->core_cache->reg_list[15].dirty = 1;
-	armv4_5->core_cache->reg_list[15].valid = 1;
+	buf_set_u32(armv4_5->pc->value, 0, 32, 0x0);
+	armv4_5->pc->dirty = 1;
+	armv4_5->pc->valid = 1;
 
 	arm720t_disable_mmu_caches(target, 1, 1, 1);
 	arm720t->armv4_5_mmu.mmu_enabled = 0;
diff --git a/src/target/arm7_9_common.c b/src/target/arm7_9_common.c
index 509e91e4..21767291 100644
--- a/src/target/arm7_9_common.c
+++ b/src/target/arm7_9_common.c
@@ -1235,9 +1235,9 @@ int arm7_9_soft_reset_halt(struct target *target)
 	armv4_5->cpsr->dirty = 1;
 
 	/* start fetching from 0x0 */
-	buf_set_u32(armv4_5->core_cache->reg_list[15].value, 0, 32, 0x0);
-	armv4_5->core_cache->reg_list[15].dirty = 1;
-	armv4_5->core_cache->reg_list[15].valid = 1;
+	buf_set_u32(armv4_5->pc->value, 0, 32, 0x0);
+	armv4_5->pc->dirty = 1;
+	armv4_5->pc->valid = 1;
 
 	/* reset registers */
 	for (i = 0; i <= 14; i++)
@@ -1721,9 +1721,10 @@ int arm7_9_restore_context(struct target *target)
 	}
 
 	/* restore PC */
-	LOG_DEBUG("writing PC with value 0x%8.8" PRIx32 "", buf_get_u32(armv4_5->core_cache->reg_list[15].value, 0, 32));
-	arm7_9->write_pc(target, buf_get_u32(armv4_5->core_cache->reg_list[15].value, 0, 32));
-	armv4_5->core_cache->reg_list[15].dirty = 0;
+	LOG_DEBUG("writing PC with value 0x%8.8" PRIx32,
+			buf_get_u32(armv4_5->pc->value, 0, 32));
+	arm7_9->write_pc(target, buf_get_u32(armv4_5->pc->value, 0, 32));
+	armv4_5->pc->dirty = 0;
 
 	if (arm7_9->post_restore_context)
 		arm7_9->post_restore_context(target);
@@ -1815,15 +1816,17 @@ int arm7_9_resume(struct target *target, int current, uint32_t address, int hand
 
 	/* current = 1: continue on current pc, otherwise continue at <address> */
 	if (!current)
-		buf_set_u32(armv4_5->core_cache->reg_list[15].value, 0, 32, address);
+		buf_set_u32(armv4_5->pc->value, 0, 32, address);
 
 	uint32_t current_pc;
-	current_pc = buf_get_u32(armv4_5->core_cache->reg_list[15].value, 0, 32);
+	current_pc = buf_get_u32(armv4_5->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(armv4_5->core_cache->reg_list[15].value, 0, 32))))
+		breakpoint = breakpoint_find(target,
+				buf_get_u32(armv4_5->pc->value, 0, 32));
+		if (breakpoint != NULL)
 		{
 			LOG_DEBUG("unset breakpoint at 0x%8.8" PRIx32 " (id: %d)", breakpoint->address, breakpoint->unique_id );
 			if ((retval = arm7_9_unset_breakpoint(target, breakpoint)) != ERROR_OK)
@@ -1881,7 +1884,8 @@ int arm7_9_resume(struct target *target, int current, uint32_t address, int hand
 			}
 
 			arm7_9_debug_entry(target);
-			LOG_DEBUG("new PC after step: 0x%8.8" PRIx32 "", buf_get_u32(armv4_5->core_cache->reg_list[15].value, 0, 32));
+			LOG_DEBUG("new PC after step: 0x%8.8" PRIx32,
+					buf_get_u32(armv4_5->pc->value, 0, 32));
 
 			LOG_DEBUG("set breakpoint at 0x%8.8" PRIx32 "", breakpoint->address);
 			if ((retval = arm7_9_set_breakpoint(target, breakpoint)) != ERROR_OK)
@@ -1957,7 +1961,7 @@ void arm7_9_enable_eice_step(struct target *target, uint32_t next_pc)
 	struct arm7_9_common *arm7_9 = target_to_arm7_9(target);
 	struct arm *armv4_5 = &arm7_9->armv4_5_common;
 	uint32_t current_pc;
-	current_pc = buf_get_u32(armv4_5->core_cache->reg_list[15].value, 0, 32);
+	current_pc = buf_get_u32(armv4_5->pc->value, 0, 32);
 
 	if (next_pc != current_pc)
 	{
@@ -2019,18 +2023,18 @@ int arm7_9_step(struct target *target, int current, uint32_t address, int handle
 
 	/* current = 1: continue on current pc, otherwise continue at <address> */
 	if (!current)
-		buf_set_u32(armv4_5->core_cache->reg_list[15].value, 0, 32, address);
+		buf_set_u32(armv4_5->pc->value, 0, 32, address);
 
-	uint32_t current_pc;
-	current_pc = buf_get_u32(armv4_5->core_cache->reg_list[15].value, 0, 32);
+	uint32_t current_pc = buf_get_u32(armv4_5->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(armv4_5->core_cache->reg_list[15].value, 0, 32))))
-			if ((retval = arm7_9_unset_breakpoint(target, breakpoint)) != ERROR_OK)
-			{
-				return retval;
-			}
+		breakpoint = breakpoint_find(target, current_pc);
+	if (breakpoint != NULL) {
+		retval = arm7_9_unset_breakpoint(target, breakpoint);
+		if (retval != ERROR_OK)
+			return retval;
+	}
 
 	target->debug_reason = DBG_REASON_SINGLESTEP;
 
diff --git a/src/target/arm7tdmi.c b/src/target/arm7tdmi.c
index 16f16b0f..530a675b 100644
--- a/src/target/arm7tdmi.c
+++ b/src/target/arm7tdmi.c
@@ -598,7 +598,8 @@ static void arm7tdmi_branch_resume_thumb(struct target *target)
 	/* fetch NOP, LDM in EXECUTE stage (1st cycle) */
 	arm7tdmi_clock_out(jtag_info, ARMV4_5_NOP, NULL, 0);
 	/* nothing fetched, LDM in EXECUTE stage (2nd cycle) */
-	arm7tdmi_clock_out(jtag_info, buf_get_u32(armv4_5->core_cache->reg_list[15].value, 0, 32) | 1, NULL, 0);
+	arm7tdmi_clock_out(jtag_info,
+			buf_get_u32(armv4_5->pc->value, 0, 32) | 1, NULL, 0);
 	/* nothing fetched, LDM in EXECUTE stage (3rd cycle) */
 	arm7tdmi_clock_out(jtag_info, ARMV4_5_NOP, NULL, 0);
 
diff --git a/src/target/arm920t.c b/src/target/arm920t.c
index 3e615451..152edcfe 100644
--- a/src/target/arm920t.c
+++ b/src/target/arm920t.c
@@ -777,9 +777,9 @@ int arm920t_soft_reset_halt(struct target *target)
 	armv4_5->cpsr->dirty = 1;
 
 	/* start fetching from 0x0 */
-	buf_set_u32(armv4_5->core_cache->reg_list[15].value, 0, 32, 0x0);
-	armv4_5->core_cache->reg_list[15].dirty = 1;
-	armv4_5->core_cache->reg_list[15].valid = 1;
+	buf_set_u32(armv4_5->pc->value, 0, 32, 0x0);
+	armv4_5->pc->dirty = 1;
+	armv4_5->pc->valid = 1;
 
 	arm920t_disable_mmu_caches(target, 1, 1, 1);
 	arm920t->armv4_5_mmu.mmu_enabled = 0;
diff --git a/src/target/arm926ejs.c b/src/target/arm926ejs.c
index 32ecf72d..d8111966 100644
--- a/src/target/arm926ejs.c
+++ b/src/target/arm926ejs.c
@@ -569,9 +569,9 @@ int arm926ejs_soft_reset_halt(struct target *target)
 	armv4_5->cpsr->dirty = 1;
 
 	/* start fetching from 0x0 */
-	buf_set_u32(armv4_5->core_cache->reg_list[15].value, 0, 32, 0x0);
-	armv4_5->core_cache->reg_list[15].dirty = 1;
-	armv4_5->core_cache->reg_list[15].valid = 1;
+	buf_set_u32(armv4_5->pc->value, 0, 32, 0x0);
+	armv4_5->pc->dirty = 1;
+	armv4_5->pc->valid = 1;
 
 	arm926ejs_disable_mmu_caches(target, 1, 1, 1);
 	arm926ejs->armv4_5_mmu.mmu_enabled = 0;
diff --git a/src/target/arm9tdmi.c b/src/target/arm9tdmi.c
index 761e7cf7..77b01b16 100644
--- a/src/target/arm9tdmi.c
+++ b/src/target/arm9tdmi.c
@@ -677,7 +677,8 @@ static void arm9tdmi_branch_resume_thumb(struct target *target)
 	/* fetch NOP, LDM in EXECUTE stage (1st cycle) */
 	arm9tdmi_clock_out(jtag_info, ARMV4_5_NOP, 0, NULL, 0);
 	/* nothing fetched, LDM in EXECUTE stage (2nd cycle) */
-	arm9tdmi_clock_out(jtag_info, ARMV4_5_NOP, buf_get_u32(armv4_5->core_cache->reg_list[15].value, 0, 32) | 1, NULL, 0);
+	arm9tdmi_clock_out(jtag_info, ARMV4_5_NOP,
+			buf_get_u32(armv4_5->pc->value, 0, 32) | 1, NULL, 0);
 	/* nothing fetched, LDM in EXECUTE stage (3rd cycle) */
 	arm9tdmi_clock_out(jtag_info, ARMV4_5_NOP, 0, NULL, 0);
 
diff --git a/src/target/arm_dpm.c b/src/target/arm_dpm.c
index 0b5e2558..8e8cc17a 100644
--- a/src/target/arm_dpm.c
+++ b/src/target/arm_dpm.c
@@ -453,8 +453,8 @@ int arm_dpm_write_dirty_registers(struct arm_dpm *dpm, bool bpwp)
 	retval = dpm_modeswitch(dpm, ARM_MODE_ANY);
 	arm->cpsr->dirty = false;
 
-	retval = dpm_write_reg(dpm, &cache->reg_list[15], 15);
-	cache->reg_list[15].dirty = false;
+	retval = dpm_write_reg(dpm, arm->pc, 15);
+	arm->pc->dirty = false;
 
 	/* flush R0 -- it's *very* dirty by now */
 	retval = dpm_write_reg(dpm, &cache->reg_list[0], 0);
diff --git a/src/target/arm_semihosting.c b/src/target/arm_semihosting.c
index 9b853d9f..24a4de57 100644
--- a/src/target/arm_semihosting.c
+++ b/src/target/arm_semihosting.c
@@ -393,8 +393,8 @@ static int do_semihosting(struct target *target)
 	armv4_5->core_cache->reg_list[0].dirty = 1;
 
 	/* LR --> PC */
-	buf_set_u32(armv4_5->core_cache->reg_list[15].value, 0, 32, lr);
-	armv4_5->core_cache->reg_list[15].dirty = 1;
+	buf_set_u32(armv4_5->pc->value, 0, 32, lr);
+	armv4_5->pc->dirty = 1;
 
 	/* saved PSR --> current PSR */
 	buf_set_u32(armv4_5->cpsr->value, 0, 32, spsr);
@@ -429,7 +429,7 @@ int arm_semihosting(struct target *target, int *retval)
 		return 0;
 
 	/* Check for PC == 0x00000008 or 0xffff0008: Supervisor Call vector. */
-	r = arm->core_cache->reg_list + 15;
+	r = arm->pc;
 	pc = buf_get_u32(r->value, 0, 32);
 	if (pc != 0x00000008 && pc != 0xffff0008)
 		return 0;
diff --git a/src/target/armv4_5.c b/src/target/armv4_5.c
index 8d3a8917..a4a15b40 100644
--- a/src/target/armv4_5.c
+++ b/src/target/armv4_5.c
@@ -577,6 +577,7 @@ struct reg_cache *arm_build_reg_cache(struct target *target, struct arm *arm)
 		cache->num_regs++;
 	}
 
+	arm->pc = reg_list + 15;
 	arm->cpsr = reg_list + ARMV4_5_CPSR;
 	arm->core_cache = cache;
 	return cache;
@@ -598,8 +599,7 @@ int arm_arch_state(struct target *target)
 			debug_reason_name(target),
 			arm_mode_name(armv4_5->core_mode),
 			buf_get_u32(armv4_5->cpsr->value, 0, 32),
-			buf_get_u32(armv4_5->core_cache->reg_list[15].value,
-					0, 32),
+			buf_get_u32(armv4_5->pc->value, 0, 32),
 			armv4_5->is_semihosting ? ", semihosting" : "");
 
 	return ERROR_OK;
@@ -1018,11 +1018,10 @@ static int armv4_5_run_algorithm_completion(struct target *target, uint32_t exit
 	}
 
 	/* fast exit: ARMv5+ code can use BKPT */
-	if (exit_point && buf_get_u32(armv4_5->core_cache->reg_list[15].value,
-				0, 32) != exit_point)
+	if (exit_point && buf_get_u32(armv4_5->pc->value, 0, 32) != exit_point)
 	{
 		LOG_WARNING("target reentered debug state, but not at the desired exit point: 0x%4.4" PRIx32 "",
-			buf_get_u32(armv4_5->core_cache->reg_list[15].value, 0, 32));
+			buf_get_u32(armv4_5->pc->value, 0, 32));
 		return ERROR_TARGET_TIMEOUT;
 	}
 
diff --git a/src/target/armv7m.c b/src/target/armv7m.c
index faa886b4..466c0b2a 100644
--- a/src/target/armv7m.c
+++ b/src/target/armv7m.c
@@ -282,7 +282,7 @@ int armv7m_get_gdb_reg_list(struct target *target, struct reg **reg_list[], int
 
 	/* ARMV7M is always in thumb mode, try to make GDB understand this
 	 * if it does not support this arch */
-	*((char*)armv7m->core_cache->reg_list[15].value) |= 1;
+	*((char*)armv7m->arm.pc->value) |= 1;
 #else
 	(*reg_list)[25] = &armv7m->core_cache->reg_list[ARMV7M_xPSR];
 #endif
@@ -485,7 +485,7 @@ int armv7m_arch_state(struct target *target)
 		armv7m_mode_strings[armv7m->core_mode],
 		armv7m_exception_string(armv7m->exception_number),
 		buf_get_u32(arm->cpsr->value, 0, 32),
-		buf_get_u32(armv7m->core_cache->reg_list[ARMV7M_PC].value, 0, 32),
+		buf_get_u32(arm->pc->value, 0, 32),
 		(ctrl & 0x02) ? 'p' : 'm',
 		sp);
 
@@ -535,6 +535,7 @@ struct reg_cache *armv7m_build_reg_cache(struct target *target)
 	}
 
 	arm->cpsr = reg_list + ARMV7M_xPSR;
+	arm->pc = reg_list + ARMV7M_PC;
 	arm->core_cache = cache;
 	return cache;
 }
@@ -708,7 +709,7 @@ int armv7m_blank_check_memory(struct target *target,
 int armv7m_maybe_skip_bkpt_inst(struct target *target, bool *inst_found)
 {
 	struct armv7m_common *armv7m = target_to_armv7m(target);
-	struct reg *r = armv7m->core_cache->reg_list + 15;
+	struct reg *r = armv7m->arm.pc;
 	bool result = false;
 
 
diff --git a/src/target/cortex_a8.c b/src/target/cortex_a8.c
index bcdb5260..050238ce 100644
--- a/src/target/cortex_a8.c
+++ b/src/target/cortex_a8.c
@@ -695,9 +695,7 @@ static int cortex_a8_resume(struct target *target, int current,
 #endif
 
 	/* current = 1: continue on current pc, otherwise continue at <address> */
-	resume_pc = buf_get_u32(
-			armv4_5->core_cache->reg_list[15].value,
-			0, 32);
+	resume_pc = buf_get_u32(armv4_5->pc->value, 0, 32);
 	if (!current)
 		resume_pc = address;
 
@@ -721,10 +719,9 @@ static int cortex_a8_resume(struct target *target, int current,
 		return ERROR_FAIL;
 	}
 	LOG_DEBUG("resume pc = 0x%08" PRIx32, resume_pc);
-	buf_set_u32(armv4_5->core_cache->reg_list[15].value,
-			0, 32, resume_pc);
-	armv4_5->core_cache->reg_list[15].dirty = 1;
-	armv4_5->core_cache->reg_list[15].valid = 1;
+	buf_set_u32(armv4_5->pc->value, 0, 32, resume_pc);
+	armv4_5->pc->dirty = 1;
+	armv4_5->pc->valid = 1;
 
 	cortex_a8_restore_context(target, handle_breakpoints);
 
@@ -869,7 +866,7 @@ static int cortex_a8_debug_entry(struct target *target)
 			regfile[ARM_PC] -= 8;
 		}
 
-		reg = armv4_5->core_cache->reg_list + 15;
+		reg = armv4_5->pc;
 		buf_set_u32(reg->value, 0, 32, regfile[ARM_PC]);
 		reg->dirty = reg->valid;
 	}
@@ -952,7 +949,7 @@ static int cortex_a8_step(struct target *target, int current, uint32_t address,
 	}
 
 	/* current = 1: continue on current pc, otherwise continue at <address> */
-	r = armv4_5->core_cache->reg_list + 15;
+	r = armv4_5->pc;
 	if (!current)
 	{
 		buf_set_u32(r->value, 0, 32, address);
diff --git a/src/target/cortex_m3.c b/src/target/cortex_m3.c
index fbc879f1..a3b3d425 100644
--- a/src/target/cortex_m3.c
+++ b/src/target/cortex_m3.c
@@ -427,7 +427,7 @@ static int cortex_m3_debug_entry(struct target *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),
+		*(uint32_t*)(arm->pc->value),
 		target_state_name(target));
 
 	if (armv7m->post_debug_entry)
@@ -680,7 +680,7 @@ static int cortex_m3_resume(struct target *target, int current,
 	}
 
 	/* current = 1: continue on current pc, otherwise continue at <address> */
-	r = armv7m->core_cache->reg_list + 15;
+	r = armv7m->arm.pc;
 	if (!current)
 	{
 		buf_set_u32(r->value, 0, 32, address);
@@ -749,7 +749,7 @@ static int cortex_m3_step(struct target *target, int current,
 	struct armv7m_common *armv7m = &cortex_m3->armv7m;
 	struct swjdp_common *swjdp = &armv7m->swjdp_info;
 	struct breakpoint *breakpoint = NULL;
-	struct reg *pc = armv7m->core_cache->reg_list + 15;
+	struct reg *pc = armv7m->arm.pc;
 	bool bkpt_inst_found = false;
 
 	if (target->state != TARGET_HALTED)
diff --git a/src/target/feroceon.c b/src/target/feroceon.c
index 19ed0cd5..e0c3c395 100644
--- a/src/target/feroceon.c
+++ b/src/target/feroceon.c
@@ -337,7 +337,7 @@ void feroceon_branch_resume_thumb(struct target *target)
 	struct arm7_9_common *arm7_9 = armv4_5->arch_info;
 	struct arm_jtag *jtag_info = &arm7_9->jtag_info;
 	uint32_t r0 = buf_get_u32(armv4_5->core_cache->reg_list[0].value, 0, 32);
-	uint32_t pc = buf_get_u32(armv4_5->core_cache->reg_list[15].value, 0, 32);
+	uint32_t pc = buf_get_u32(armv4_5->pc->value, 0, 32);
 
 	arm9tdmi_clock_out(jtag_info, ARMV4_5_NOP, 0, NULL, 0);
 	arm9tdmi_clock_out(jtag_info, ARMV4_5_NOP, 0, NULL, 0);
@@ -519,7 +519,7 @@ int feroceon_bulk_write_memory(struct target *target, uint32_t address, uint32_t
 	/* backup clobbered processor state */
 	for (i = 0; i <= 5; i++)
 		save[i] = buf_get_u32(armv4_5->core_cache->reg_list[i].value, 0, 32);
-	save[i] = buf_get_u32(armv4_5->core_cache->reg_list[15].value, 0, 32);
+	save[i] = buf_get_u32(armv4_5->pc->value, 0, 32);
 
 	/* set up target address in r0 */
 	buf_set_u32(armv4_5->core_cache->reg_list[0].value, 0, 32, address);
@@ -572,9 +572,9 @@ int feroceon_bulk_write_memory(struct target *target, uint32_t address, uint32_t
 		armv4_5->core_cache->reg_list[i].valid = 1;
 		armv4_5->core_cache->reg_list[i].dirty = 1;
 	}
-	buf_set_u32(armv4_5->core_cache->reg_list[15].value, 0, 32, save[i]);
-	armv4_5->core_cache->reg_list[15].valid = 1;
-	armv4_5->core_cache->reg_list[15].dirty = 1;
+	buf_set_u32(armv4_5->pc->value, 0, 32, save[i]);
+	armv4_5->pc->valid = 1;
+	armv4_5->pc->dirty = 1;
 	armv4_5->core_state = core_state;
 
 	return retval;
diff --git a/src/target/xscale.c b/src/target/xscale.c
index fc71ea33..48dbc47e 100644
--- a/src/target/xscale.c
+++ b/src/target/xscale.c
@@ -941,9 +941,9 @@ static int xscale_debug_entry(struct target *target)
 	LOG_DEBUG("r0: 0x%8.8" PRIx32 "", buffer[0]);
 
 	/* move pc from buffer to register cache */
-	buf_set_u32(armv4_5->core_cache->reg_list[15].value, 0, 32, buffer[1]);
-	armv4_5->core_cache->reg_list[15].dirty = 1;
-	armv4_5->core_cache->reg_list[15].valid = 1;
+	buf_set_u32(armv4_5->pc->value, 0, 32, buffer[1]);
+	armv4_5->pc->dirty = 1;
+	armv4_5->pc->valid = 1;
 	LOG_DEBUG("pc: 0x%8.8" PRIx32 "", buffer[1]);
 
 	/* move data from buffer to register cache */
@@ -995,7 +995,7 @@ static int xscale_debug_entry(struct target *target)
 	moe = buf_get_u32(xscale->reg_cache->reg_list[XSCALE_DCSR].value, 2, 3);
 
 	/* stored PC (for calculating fixup) */
-	pc = buf_get_u32(armv4_5->core_cache->reg_list[15].value, 0, 32);
+	pc = buf_get_u32(armv4_5->pc->value, 0, 32);
 
 	switch (moe)
 	{
@@ -1042,7 +1042,7 @@ static int xscale_debug_entry(struct target *target)
 	}
 
 	/* apply PC fixup */
-	buf_set_u32(armv4_5->core_cache->reg_list[15].value, 0, 32, pc);
+	buf_set_u32(armv4_5->pc->value, 0, 32, pc);
 
 	/* on the first debug entry, identify cache type */
 	if (xscale->armv4_5_mmu.armv4_5_cache.ctype == -1)
@@ -1212,21 +1212,23 @@ static int xscale_resume(struct target *target, int current,
 
 	/* current = 1: continue on current pc, otherwise continue at <address> */
 	if (!current)
-		buf_set_u32(armv4_5->core_cache->reg_list[15].value, 0, 32, address);
+		buf_set_u32(armv4_5->pc->value, 0, 32, address);
 
-	current_pc = buf_get_u32(armv4_5->core_cache->reg_list[15].value, 0, 32);
+	current_pc = buf_get_u32(armv4_5->pc->value, 0, 32);
 
 	/* if we're at the reset vector, we have to simulate the branch */
 	if (current_pc == 0x0)
 	{
 		arm_simulate_step(target, NULL);
-		current_pc = buf_get_u32(armv4_5->core_cache->reg_list[15].value, 0, 32);
+		current_pc = buf_get_u32(armv4_5->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(armv4_5->core_cache->reg_list[15].value, 0, 32))))
+		breakpoint = breakpoint_find(target,
+				buf_get_u32(armv4_5->pc->value, 0, 32));
+		if (breakpoint != NULL)
 		{
 			uint32_t next_pc;
 
@@ -1272,8 +1274,10 @@ static int xscale_resume(struct target *target, int current,
 			}
 
 			/* send PC */
-			xscale_send_u32(target, buf_get_u32(armv4_5->core_cache->reg_list[15].value, 0, 32));
-			LOG_DEBUG("writing PC with value 0x%8.8" PRIx32 "", buf_get_u32(armv4_5->core_cache->reg_list[15].value, 0, 32));
+			xscale_send_u32(target,
+					buf_get_u32(armv4_5->pc->value, 0, 32));
+			LOG_DEBUG("writing PC with value 0x%8.8" PRIx32,
+					buf_get_u32(armv4_5->pc->value, 0, 32));
 
 			/* wait for and process debug entry */
 			xscale_debug_entry(target);
@@ -1316,8 +1320,9 @@ static int xscale_resume(struct target *target, int current,
 	}
 
 	/* send PC */
-	xscale_send_u32(target, buf_get_u32(armv4_5->core_cache->reg_list[15].value, 0, 32));
-	LOG_DEBUG("writing PC with value 0x%8.8" PRIx32 "", buf_get_u32(armv4_5->core_cache->reg_list[15].value, 0, 32));
+	xscale_send_u32(target, buf_get_u32(armv4_5->pc->value, 0, 32));
+	LOG_DEBUG("wrote PC with value 0x%8.8" PRIx32,
+			buf_get_u32(armv4_5->pc->value, 0, 32));
 
 	target->debug_reason = DBG_REASON_NOTHALTED;
 
@@ -1354,7 +1359,7 @@ static int xscale_step_inner(struct target *target, int current,
 	if ((retval = arm_simulate_step(target, &next_pc)) != ERROR_OK)
 	{
 		uint32_t current_opcode, current_pc;
-		current_pc = buf_get_u32(armv4_5->core_cache->reg_list[15].value, 0, 32);
+		current_pc = buf_get_u32(armv4_5->pc->value, 0, 32);
 
 		target_read_u32(target, current_pc, &current_opcode);
 		LOG_ERROR("BUG: couldn't calculate PC of next instruction, current opcode was 0x%8.8" PRIx32 "", current_opcode);
@@ -1399,9 +1404,12 @@ static int xscale_step_inner(struct target *target, int current,
 	}
 
 	/* send PC */
-	if ((retval = xscale_send_u32(target, buf_get_u32(armv4_5->core_cache->reg_list[15].value, 0, 32))) != ERROR_OK)
+	retval = xscale_send_u32(target,
+			buf_get_u32(armv4_5->pc->value, 0, 32));
+	if (retval != ERROR_OK)
 		return retval;
-	LOG_DEBUG("writing PC with value 0x%8.8" PRIx32, buf_get_u32(armv4_5->core_cache->reg_list[15].value, 0, 32));
+	LOG_DEBUG("wrote PC with value 0x%8.8" PRIx32,
+			buf_get_u32(armv4_5->pc->value, 0, 32));
 
 	target_call_event_callbacks(target, TARGET_EVENT_RESUMED);
 
@@ -1425,7 +1433,7 @@ static int xscale_step(struct target *target, int current,
 		uint32_t address, int handle_breakpoints)
 {
 	struct arm *armv4_5 = target_to_arm(target);
-	struct breakpoint *breakpoint = target->breakpoints;
+	struct breakpoint *breakpoint = NULL;
 
 	uint32_t current_pc;
 	int retval;
@@ -1438,16 +1446,16 @@ static int xscale_step(struct target *target, int current,
 
 	/* current = 1: continue on current pc, otherwise continue at <address> */
 	if (!current)
-		buf_set_u32(armv4_5->core_cache->reg_list[15].value, 0, 32, address);
+		buf_set_u32(armv4_5->pc->value, 0, 32, address);
 
-	current_pc = buf_get_u32(armv4_5->core_cache->reg_list[15].value, 0, 32);
+	current_pc = buf_get_u32(armv4_5->pc->value, 0, 32);
 
 	/* if we're at the reset vector, we have to simulate the step */
 	if (current_pc == 0x0)
 	{
 		if ((retval = arm_simulate_step(target, NULL)) != ERROR_OK)
 			return retval;
-		current_pc = buf_get_u32(armv4_5->core_cache->reg_list[15].value, 0, 32);
+		current_pc = buf_get_u32(armv4_5->pc->value, 0, 32);
 
 		target->debug_reason = DBG_REASON_SINGLESTEP;
 		target_call_event_callbacks(target, TARGET_EVENT_HALTED);
@@ -1457,11 +1465,13 @@ static int xscale_step(struct target *target, int current,
 
 	/* the front-end may request us not to handle breakpoints */
 	if (handle_breakpoints)
-		if ((breakpoint = breakpoint_find(target, buf_get_u32(armv4_5->core_cache->reg_list[15].value, 0, 32))))
-		{
-			if ((retval = xscale_unset_breakpoint(target, breakpoint)) != ERROR_OK)
-				return retval;
-		}
+		breakpoint = breakpoint_find(target,
+				buf_get_u32(armv4_5->pc->value, 0, 32));
+	if (breakpoint != NULL) {
+		retval = xscale_unset_breakpoint(target, breakpoint);
+		if (retval != ERROR_OK)
+			return retval;
+	}
 
 	retval = xscale_step_inner(target, current, address, handle_breakpoints);
 
@@ -2568,7 +2578,8 @@ static int xscale_read_trace(struct target *target)
 	(*trace_data_p)->next = NULL;
 	(*trace_data_p)->chkpt0 = trace_buffer[256];
 	(*trace_data_p)->chkpt1 = trace_buffer[257];
-	(*trace_data_p)->last_instruction = buf_get_u32(armv4_5->core_cache->reg_list[15].value, 0, 32);
+	(*trace_data_p)->last_instruction =
+			buf_get_u32(armv4_5->pc->value, 0, 32);
 	(*trace_data_p)->entries = malloc(sizeof(struct xscale_trace_entry) * (256 - j));
 	(*trace_data_p)->depth = 256 - j;
 
@@ -3375,7 +3386,8 @@ COMMAND_HANDLER(xscale_handle_trace_buffer_command)
 		/* if we enable the trace buffer in fill-once
 		 * mode we know the address of the first instruction */
 		xscale->trace.pc_ok = 1;
-		xscale->trace.current_pc = buf_get_u32(armv4_5->core_cache->reg_list[15].value, 0, 32);
+		xscale->trace.current_pc =
+				buf_get_u32(armv4_5->pc->value, 0, 32);
 	}
 	else
 	{