Add awareness of halt group cause. (#472)

Change-Id: I7f7b967ccaa3d1ff05a7e7d0c2a7ba4fa7d68ac0

src/target/riscv/riscv-013.c

@@ -92,6 +92,7 @@ static int	riscv013_test_compliance(struct target *target);
 #define CSR_DCSR_CAUSE_DEBUGINT	3
 #define CSR_DCSR_CAUSE_STEP		4
 #define CSR_DCSR_CAUSE_HALT		5
+#define CSR_DCSR_CAUSE_GROUP	6
 
 #define RISCV013_INFO(r) riscv013_info_t *r = get_info(target)
 
@@ -3878,6 +3879,8 @@ static enum riscv_halt_reason riscv013_halt_reason(struct target *target)
 	case CSR_DCSR_CAUSE_DEBUGINT:
 	case CSR_DCSR_CAUSE_HALT:
 		return RISCV_HALT_INTERRUPT;
+	case CSR_DCSR_CAUSE_GROUP:
+		return RISCV_HALT_GROUP;
 	}
 
 	LOG_ERROR("Unknown DCSR cause field: %x", (int)get_field(dcsr, CSR_DCSR_CAUSE));

src/target/riscv/riscv.c

@@ -1931,6 +1931,7 @@ int set_debug_reason(struct target *target, int hartid)
 			target->debug_reason = DBG_REASON_WATCHPOINT;
 			break;
 		case RISCV_HALT_INTERRUPT:
+		case RISCV_HALT_GROUP:
 			target->debug_reason = DBG_REASON_DBGRQ;
 			break;
 		case RISCV_HALT_SINGLESTEP:

src/target/riscv/riscv.h

@@ -40,6 +40,7 @@ enum riscv_halt_reason {
 	RISCV_HALT_SINGLESTEP,
 	RISCV_HALT_TRIGGER,
 	RISCV_HALT_UNKNOWN,
+	RISCV_HALT_GROUP,
 	RISCV_HALT_ERROR
 };