rtt_server: Add option for a message when client connects

This is useful when using the SEGGER RTT tooling, as the SEGGER RTT tool J-Link RTT Viewer version 7.84f requires that it receives a messages immediately after connecting. Otherwise it will give a timeout and it will not connect. Change-Id: I9240a1b6a93cd5c0fbd18292afb33b89013d78bf Signed-off-by: Thiemo van Engelen <[email protected]> Reviewed-on: https://review.openocd.org/c/openocd/+/7752 Tested-by: jenkins Reviewed-by: zapb <[email protected]> Reviewed-by: Antonio Borneo <[email protected]>
openocd-org · Nov 24, 2023 · 53e67c3 · 53e67c3
1 parent acde409
commit 53e67c3
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Showing 2 changed files with 24 additions and 5 deletions.
diff --git a/doc/openocd.texi b/doc/openocd.texi
@@ -9448,8 +9448,9 @@ Return a list of all channels and their properties as Tcl list.
 The list can be manipulated easily from within scripts.
 @end deffn
 
-@deffn {Command} {rtt server start} port channel
-Start a TCP server on @var{port} for the channel @var{channel}.
+@deffn {Command} {rtt server start} port channel [message]
+Start a TCP server on @var{port} for the channel @var{channel}. When
+@var{message} is not empty, it will be sent to a client when it connects.
 @end deffn
 
 @deffn {Command} {rtt server stop} port

diff --git a/src/server/rtt_server.c b/src/server/rtt_server.c
@@ -25,6 +25,7 @@
 
 struct rtt_service {
 	unsigned int channel;
+	char *hello_message;
 };
 
 static int read_callback(unsigned int channel, const uint8_t *buffer,
@@ -65,6 +66,9 @@ static int rtt_new_connection(struct connection *connection)
 	if (ret != ERROR_OK)
 		return ret;
 
+	if (service->hello_message)
+		connection_write(connection, service->hello_message, strlen(service->hello_message));
+
 	return ERROR_OK;
 }
 
@@ -117,16 +121,30 @@ COMMAND_HANDLER(handle_rtt_start_command)
 	int ret;
 	struct rtt_service *service;
 
-	if (CMD_ARGC != 2)
+	if (CMD_ARGC < 2 || CMD_ARGC > 3)
 		return ERROR_COMMAND_SYNTAX_ERROR;
 
-	service = malloc(sizeof(struct rtt_service));
+	service = calloc(1, sizeof(struct rtt_service));
 
 	if (!service)
 		return ERROR_FAIL;
 
 	COMMAND_PARSE_NUMBER(uint, CMD_ARGV[1], service->channel);
 
+	if (CMD_ARGC >= 3) {
+		const char *hello_message = CMD_ARGV[2];
+		size_t hello_length = strlen(hello_message);
+
+		service->hello_message = malloc(hello_length + 2);
+		if (!service->hello_message) {
+			LOG_ERROR("Out of memory");
+			free(service);
+			return ERROR_FAIL;
+		}
+		strcpy(service->hello_message, hello_message);
+		service->hello_message[hello_length] = '\n';
+		service->hello_message[hello_length + 1] = '\0';
+	}
 	ret = add_service(&rtt_service_driver, CMD_ARGV[0], CONNECTION_LIMIT_UNLIMITED, service);
 
 	if (ret != ERROR_OK) {
@@ -153,7 +171,7 @@ static const struct command_registration rtt_server_subcommand_handlers[] = {
 		.handler = handle_rtt_start_command,
 		.mode = COMMAND_ANY,
 		.help = "Start a RTT server",
-		.usage = "<port> <channel>"
+		.usage = "<port> <channel> [message]"
 	},
 	{
 		.name = "stop",