9 files changed, 130 insertions, 0 deletions

diff --git a/src/target/breakpoints.c b/src/target/breakpoints.c
index 436acddc..422705bc 100644
--- a/src/target/breakpoints.c
+++ b/src/target/breakpoints.c
@@ -500,3 +500,22 @@ void watchpoint_clear_target(struct target *target)
 	while (target->watchpoints != NULL)
 		watchpoint_free(target, target->watchpoints);
 }
+
+int watchpoint_hit(struct target *target, enum watchpoint_rw *rw, uint32_t *address)
+{
+	int retval;
+	struct watchpoint *hit_watchpoint;
+
+	retval = target_hit_watchpoint(target, &hit_watchpoint);
+	if (retval != ERROR_OK)
+		return ERROR_FAIL;
+
+	*rw = hit_watchpoint->rw;
+	*address = hit_watchpoint->address;
+
+	LOG_DEBUG("Found hit watchpoint at 0x%8.8" PRIx32 " (WPID: %d)",
+		hit_watchpoint->address,
+		hit_watchpoint->unique_id);
+
+	return ERROR_OK;
+}
diff --git a/src/target/breakpoints.h b/src/target/breakpoints.h
index d9f4ba5d..0246acd3 100644
--- a/src/target/breakpoints.h
+++ b/src/target/breakpoints.h
@@ -72,4 +72,7 @@ int watchpoint_add(struct target *target,
 		enum watchpoint_rw rw, uint32_t value, uint32_t mask);
 void watchpoint_remove(struct target *target, uint32_t address);
 
+/* report type and address of just hit watchpoint */
+int watchpoint_hit(struct target *target, enum watchpoint_rw *rw, uint32_t *address);
+
 #endif /* BREAKPOINTS_H */
diff --git a/src/target/nds32_v2.c b/src/target/nds32_v2.c
index 90961d7d..3f5f636f 100644
--- a/src/target/nds32_v2.c
+++ b/src/target/nds32_v2.c
@@ -534,6 +534,42 @@ static int nds32_v2_get_exception_address(struct nds32 *nds32,
 	return ERROR_OK;
 }
 
+/**
+ * find out which watchpoint hits
+ * get exception address and compare the address to watchpoints
+ */
+static int nds32_v2_hit_watchpoint(struct target *target,
+		struct watchpoint **hit_watchpoint)
+{
+	uint32_t exception_address;
+	struct watchpoint *wp;
+	static struct watchpoint scan_all_watchpoint;
+	struct nds32 *nds32 = target_to_nds32(target);
+
+	scan_all_watchpoint.address = 0;
+	scan_all_watchpoint.rw = WPT_WRITE;
+	scan_all_watchpoint.next = 0;
+	scan_all_watchpoint.unique_id = 0x5CA8;
+
+	exception_address = nds32->watched_address;
+
+	if (exception_address == 0) {
+		/* send watch:0 to tell GDB to do software scan for hitting multiple watchpoints */
+		*hit_watchpoint = &scan_all_watchpoint;
+		return ERROR_OK;
+	}
+
+	for (wp = target->watchpoints; wp; wp = wp->next) {
+		if (((exception_address ^ wp->address) & (~wp->mask)) == 0) {
+			/* TODO: dispel false match */
+			*hit_watchpoint = wp;
+			return ERROR_OK;
+		}
+	}
+
+	return ERROR_FAIL;
+}
+
 static int nds32_v2_run_algorithm(struct target *target,
 		int num_mem_params,
 		struct mem_param *mem_params,
@@ -747,6 +783,7 @@ struct target_type nds32_v2_target = {
 	.remove_breakpoint = nds32_v2_remove_breakpoint,
 	.add_watchpoint = nds32_v2_add_watchpoint,
 	.remove_watchpoint = nds32_v2_remove_watchpoint,
+	.hit_watchpoint = nds32_v2_hit_watchpoint,
 
 	/* MMU */
 	.mmu = nds32_mmu,
diff --git a/src/target/nds32_v3.c b/src/target/nds32_v3.c
index dc0ca5a6..868260dc 100644
--- a/src/target/nds32_v3.c
+++ b/src/target/nds32_v3.c
@@ -506,6 +506,7 @@ struct target_type nds32_v3_target = {
 	.remove_breakpoint = nds32_v3_remove_breakpoint,
 	.add_watchpoint = nds32_v3_add_watchpoint,
 	.remove_watchpoint = nds32_v3_remove_watchpoint,
+	.hit_watchpoint = nds32_v3_hit_watchpoint,
 
 	/* MMU */
 	.mmu = nds32_mmu,
diff --git a/src/target/nds32_v3_common.c b/src/target/nds32_v3_common.c
index 49d84131..2fbd1a37 100644
--- a/src/target/nds32_v3_common.c
+++ b/src/target/nds32_v3_common.c
@@ -294,6 +294,45 @@ int nds32_v3_checksum_memory(struct target *target,
 	return ERROR_FAIL;
 }
 
+/**
+ * find out which watchpoint hits
+ * get exception address and compare the address to watchpoints
+ */
+int nds32_v3_hit_watchpoint(struct target *target,
+		struct watchpoint **hit_watchpoint)
+{
+	static struct watchpoint scan_all_watchpoint;
+
+	uint32_t exception_address;
+	struct watchpoint *wp;
+	struct nds32 *nds32 = target_to_nds32(target);
+
+	exception_address = nds32->watched_address;
+
+	if (exception_address == 0xFFFFFFFF)
+		return ERROR_FAIL;
+
+	if (exception_address == 0) {
+		scan_all_watchpoint.address = 0;
+		scan_all_watchpoint.rw = WPT_WRITE;
+		scan_all_watchpoint.next = 0;
+		scan_all_watchpoint.unique_id = 0x5CA8;
+
+		*hit_watchpoint = &scan_all_watchpoint;
+		return ERROR_OK;
+	}
+
+	for (wp = target->watchpoints; wp; wp = wp->next) {
+		if (((exception_address ^ wp->address) & (~wp->mask)) == 0) {
+			*hit_watchpoint = wp;
+
+			return ERROR_OK;
+		}
+	}
+
+	return ERROR_FAIL;
+}
+
 int nds32_v3_target_create_common(struct target *target, struct nds32 *nds32)
 {
 	nds32->register_map = nds32_v3_register_mapping;
diff --git a/src/target/nds32_v3m.c b/src/target/nds32_v3m.c
index 18987323..c37798af 100644
--- a/src/target/nds32_v3m.c
+++ b/src/target/nds32_v3m.c
@@ -494,6 +494,7 @@ struct target_type nds32_v3m_target = {
 	.remove_breakpoint = nds32_v3m_remove_breakpoint,
 	.add_watchpoint = nds32_v3m_add_watchpoint,
 	.remove_watchpoint = nds32_v3m_remove_watchpoint,
+	.hit_watchpoint = nds32_v3_hit_watchpoint,
 
 	/* MMU */
 	.mmu = nds32_mmu,
diff --git a/src/target/target.c b/src/target/target.c
index c5b80d64..4c31fbea 100644
--- a/src/target/target.c
+++ b/src/target/target.c
@@ -1035,6 +1035,23 @@ int target_remove_watchpoint(struct target *target,
 {
 	return target->type->remove_watchpoint(target, watchpoint);
 }
+int target_hit_watchpoint(struct target *target,
+		struct watchpoint **hit_watchpoint)
+{
+	if (target->state != TARGET_HALTED) {
+		LOG_WARNING("target %s is not halted", target->cmd_name);
+		return ERROR_TARGET_NOT_HALTED;
+	}
+
+	if (target->type->hit_watchpoint == NULL) {
+		/* For backward compatible, if hit_watchpoint is not implemented,
+		 * return ERROR_FAIL such that gdb_server will not take the nonsense
+		 * information. */
+		return ERROR_FAIL;
+	}
+
+	return target->type->hit_watchpoint(target, hit_watchpoint);
+}
 
 int target_get_gdb_reg_list(struct target *target,
 		struct reg **reg_list[], int *reg_list_size,
diff --git a/src/target/target.h b/src/target/target.h
index 42414c69..09895bba 100644
--- a/src/target/target.h
+++ b/src/target/target.h
@@ -400,6 +400,14 @@ int target_remove_watchpoint(struct target *target,
 		struct watchpoint *watchpoint);
 
 /**
+ * Find out the just hit @a watchpoint for @a target.
+ *
+ * This routine is a wrapper for target->type->hit_watchpoint.
+ */
+int target_hit_watchpoint(struct target *target,
+		struct watchpoint **watchpoint);
+
+/**
  * Obtain the registers for GDB.
  *
  * This routine is a wrapper for target->type->get_gdb_reg_list.
diff --git a/src/target/target_type.h b/src/target/target_type.h
index 4d9a33f9..0b8d5daa 100644
--- a/src/target/target_type.h
+++ b/src/target/target_type.h
@@ -174,6 +174,11 @@ struct target_type {
 	 */
 	int (*remove_watchpoint)(struct target *target, struct watchpoint *watchpoint);
 
+	/* Find out just hit watchpoint. After the target hits a watchpoint, the
+	 * information could assist gdb to locate where the modified/accessed memory is.
+	 */
+	int (*hit_watchpoint)(struct target *target, struct watchpoint **hit_watchpoint);
+
 	/**
 	 * Target algorithm support.  Do @b not call this method directly,
 	 * use target_run_algorithm() instead.