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 <tvanengelen@victronenergy.com>
Reviewed-on: https://review.openocd.org/c/openocd/+/7752
Tested-by: jenkins
Reviewed-by: zapb <dev@zapb.de>
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>

diff --git a/doc/openocd.texi b/doc/openocd.texi
index 5d73fd1744228636e0d5a4ba9e47ccac03152376..e8b207c524820cb441f13ccce59540378a81a826 100644 (file)
--- 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
index df2247bacd004cc18e0f111c25f695fc2840a3a8..97691534751caf1e29c44023d8cc8f87b7040ea7 100644 (file)
--- 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",