rtos: facilitate RTOS SMP handling

The RTOS handlers present OS threads to gdb but the openocd
target layer only knows about CPU cores (hardware threads).
This patch allows closing this gap inside the RTOS handler.

The default implementation just returns the current core, but
a RTOS handler can provide its own function that associates a
an OS thread with a core.

Change-Id: I12cafe50b38a38b28057bc5d3a708aa20bf60515
Signed-off-by: Matthias Welwarsky <matthias.welwarsky@sysgo.com>
Reviewed-on: http://openocd.zylin.com/3997
Reviewed-by: Matthias Welwarsky <matthias@welwarsky.de>
Tested-by: jenkins

src/rtos/rtos.c

@@ -57,6 +57,15 @@ int rtos_smp_init(struct target *target)
 	return ERROR_TARGET_INIT_FAILED;
 }
 
+static int rtos_target_for_threadid(struct connection *connection, int64_t threadid, struct target **t)
+{
+	struct target *curr = get_target_from_connection(connection);
+	if (t)
+		*t = curr;
+
+	return ERROR_OK;
+}
+
 static int os_alloc(struct target *target, struct rtos_type *ostype)
 {
 	struct rtos *os = target->rtos = calloc(1, sizeof(struct rtos));
@@ -72,6 +81,7 @@ static int os_alloc(struct target *target, struct rtos_type *ostype)
 
 	/* RTOS drivers can override the packet handler in _create(). */
 	os->gdb_thread_packet = rtos_thread_packet;
+	os->gdb_target_for_threadid = rtos_target_for_threadid;
 
 	return JIM_OK;
 }

src/rtos/rtos.h

@@ -54,6 +54,7 @@ struct rtos {
 	struct thread_detail *thread_details;
 	int thread_count;
 	int (*gdb_thread_packet)(struct connection *connection, char const *packet, int packet_size);
+	int (*gdb_target_for_threadid)(struct connection *connection, int64_t thread_id, struct target **p_target);
 	void *rtos_specific_params;
 };
 

src/server/gdb_server.c

@@ -764,8 +764,12 @@ static void gdb_signal_reply(struct target *target, struct connection *connectio
 
 		current_thread[0] = '\0';
 		if (target->rtos != NULL) {
-			snprintf(current_thread, sizeof(current_thread), "thread:%016" PRIx64 ";", target->rtos->current_thread);
+			struct target *ct;
+			snprintf(current_thread, sizeof(current_thread), "thread:%016" PRIx64 ";",
+					target->rtos->current_thread);
 			target->rtos->current_threadid = target->rtos->current_thread;
+			target->rtos->gdb_target_for_threadid(connection, target->rtos->current_threadid, &ct);
+			signal_var = gdb_last_signal(ct);
 		}
 
 		sig_reply_len = snprintf(sig_reply, sizeof(sig_reply), "T%2.2x%s%s",
@@ -2614,6 +2618,9 @@ static bool gdb_handle_vcont_packet(struct connection *connection, const char *p
 				parse = endp;
 			}
 
+			if (target->rtos != NULL)
+				target->rtos->gdb_target_for_threadid(connection, thread_id, &ct);
+
 			if (parse[0] == ';') {
 				++parse;
 				--packet_size;
@@ -3108,7 +3115,10 @@ static int gdb_input_inner(struct connection *connection)
 
 		if (gdb_con->ctrl_c) {
 			if (target->state == TARGET_RUNNING) {
-				retval = target_halt(target);
+				struct target *t = target;
+				if (target->rtos)
+					target->rtos->gdb_target_for_threadid(connection, target->rtos->current_threadid, &t);
+				retval = target_halt(t);
 				if (retval != ERROR_OK)
 					target_call_event_callbacks(target, TARGET_EVENT_GDB_HALT);
 				gdb_con->ctrl_c = 0;