cortexm: add support for DWTv2 so that watchpoints work on Armv8-M (m…

…33,...)
blackmagic-debug · Dec 4, 2024 · 54db90c · 54db90c
1 parent b0eb8d0
commit 54db90c
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Showing 2 changed files with 34 additions and 5 deletions.
diff --git a/src/target/cortexm.c b/src/target/cortexm.c
@@ -1062,6 +1062,25 @@ static uint32_t cortexm_dwt_func(target_s *target, target_breakwatch_e type)
 	}
 }
 
+static uint32_t cortexm_dwtv2_func(target_breakwatch_e type, size_t len)
+{
+	uint32_t value = CORTEXM_DWTv2_FUNC_ACTION_DEBUG_EVENT | CORTEXM_DWTv2_FUNC_LEN_VALUE(len);
+	switch (type) {
+	case TARGET_WATCH_WRITE:
+		value |= CORTEXM_DWTv2_FUNC_MATCH_WRITE;
+		break;
+	case TARGET_WATCH_READ:
+		value |= CORTEXM_DWTv2_FUNC_MATCH_READ;
+		break;
+	case TARGET_WATCH_ACCESS:
+		value |= CORTEXM_DWTv2_FUNC_MATCH_ACCESS;
+		break;
+	default:
+		return 0U;
+	}
+	return value;
+}
+
 static int cortexm_breakwatch_set(target_s *target, breakwatch_s *breakwatch)
 {
 	cortexm_priv_s *priv = target->priv;
@@ -1103,11 +1122,14 @@ static int cortexm_breakwatch_set(target_s *target, breakwatch_s *breakwatch)
 			return -1;
 
 		priv->base.watchpoints_mask |= 1U << i;
-
-		target_mem32_write32(target, CORTEXM_DWT_COMP(i), val);
-		target_mem32_write32(target, CORTEXM_DWT_MASK(i), cortexm_dwt_mask(breakwatch->size));
-		target_mem32_write32(target, CORTEXM_DWT_FUNC(i), cortexm_dwt_func(target, breakwatch->type));
-
+		if ((target->target_options & CORTEXM_TOPT_FLAVOUR_V8M)) {
+			target_mem32_write32(target, CORTEXM_DWT_COMP(i), val);
+			target_mem32_write32(target, CORTEXM_DWT_FUNC(i), cortexm_dwtv2_func(breakwatch->type, breakwatch->size));
+		} else {
+			target_mem32_write32(target, CORTEXM_DWT_COMP(i), val);
+			target_mem32_write32(target, CORTEXM_DWT_MASK(i), cortexm_dwt_mask(breakwatch->size));
+			target_mem32_write32(target, CORTEXM_DWT_FUNC(i), cortexm_dwt_func(target, breakwatch->type));
+		}
 		breakwatch->reserved[0] = i;
 		return 0;
 	default:

diff --git a/src/target/cortexm.h b/src/target/cortexm.h
@@ -164,6 +164,13 @@ extern unsigned cortexm_wait_timeout;
 #define CORTEXM_DWT_FUNC_FUNC_READ      (5U << 0U)
 #define CORTEXM_DWT_FUNC_FUNC_WRITE     (6U << 0U)
 #define CORTEXM_DWT_FUNC_FUNC_ACCESS    (7U << 0U)
+/* Variant for DWTv2 */
+#define CORTEXM_DWTv2_FUNC_MATCH_READ         (6U << 0U)
+#define CORTEXM_DWTv2_FUNC_MATCH_WRITE        (5U << 0U)
+#define CORTEXM_DWTv2_FUNC_MATCH_ACCESS       (4U << 0U)
+#define CORTEXM_DWTv2_FUNC_ACTION_TRIGGER     (0U << 4U)
+#define CORTEXM_DWTv2_FUNC_ACTION_DEBUG_EVENT (1U << 4U)
+#define CORTEXM_DWTv2_FUNC_LEN_VALUE(len)     (((len) >> 1) << 10U)
 
 #define CORTEXM_XPSR_THUMB          (1U << 24U)
 #define CORTEXM_XPSR_EXCEPTION_MASK 0x0000001fU