arm: semihosting: set command line arguments

Add "arm semihosting_cmdline [argv0 argv1 ...]" for setting the
command line arguments for the debuggee.

[andreas.fritiofson@gmail.com]: Dynamic allocation, empty default

Change-Id: I831ddd161d602f251940e29608a154e9590fdee1
Signed-off-by: Christian Groessler <chris@groessler.org>
Signed-off-by: Andreas Fritiofson <andreas.fritiofson@gmail.com>
Reviewed-on: http://openocd.zylin.com/3106
Tested-by: jenkins

doc/openocd.texi

@@ -7604,6 +7604,20 @@ requests by using a special SVC instruction that is trapped at the
 Supervisor Call vector by OpenOCD.
 @end deffn
 
+@deffn Command {arm semihosting_cmdline} [@option{enable}|@option{disable}]
+@cindex ARM semihosting
+Set the command line to be passed to the debuggee.
+
+@example
+arm semihosting_cmdline argv0 argv1 argv2 ...
+@end example
+
+This option lets one set the command line arguments to be passed to
+the program. The first argument (argv0) is the program name in a
+standard C environment (argv[0]). Depending on the program (not much
+programs look at argv[0]), argv0 is ignored and can be any string.
+@end deffn
+
 @deffn Command {arm semihosting_fileio} [@option{enable}|@option{disable}]
 @cindex ARM semihosting
 Display status of semihosting fileio, after optionally changing that

src/target/arm.h

@@ -157,6 +157,9 @@ struct arm {
 
 	int (*setup_semihosting)(struct target *target, int enable);
 
+	/** Semihosting command line. */
+	char *semihosting_cmdline;
+
 	/** Backpointer to the target. */
 	struct target *target;
 

src/target/arm_semihosting.c

@@ -465,7 +465,7 @@ static int do_semihosting(struct target *target)
 		else {
 			uint32_t a = target_buffer_get_u32(target, params+0);
 			uint32_t l = target_buffer_get_u32(target, params+4);
-			char *arg = "foobar";
+			char *arg = arm->semihosting_cmdline != NULL ? arm->semihosting_cmdline : "";
 			uint32_t s = strlen(arg) + 1;
 			if (l < s)
 				arm->semihosting_result = -1;

src/target/armv4_5.c

@@ -1091,6 +1091,42 @@ COMMAND_HANDLER(handle_arm_semihosting_fileio_command)
 	return ERROR_OK;
 }
 
+COMMAND_HANDLER(handle_arm_semihosting_cmdline)
+{
+	struct target *target = get_current_target(CMD_CTX);
+	unsigned int i;
+
+	if (target == NULL) {
+		LOG_ERROR("No target selected");
+		return ERROR_FAIL;
+	}
+
+	struct arm *arm = target_to_arm(target);
+
+	if (!is_arm(arm)) {
+		command_print(CMD_CTX, "current target isn't an ARM");
+		return ERROR_FAIL;
+	}
+
+	if (!arm->setup_semihosting) {
+		command_print(CMD_CTX, "semihosting not supported for current target");
+		return ERROR_FAIL;
+	}
+
+	free(arm->semihosting_cmdline);
+	arm->semihosting_cmdline = CMD_ARGC > 0 ? strdup(CMD_ARGV[0]) : NULL;
+
+	for (i = 1; i < CMD_ARGC; i++) {
+		char *cmdline = alloc_printf("%s %s", arm->semihosting_cmdline, CMD_ARGV[i]);
+		if (cmdline == NULL)
+			break;
+		free(arm->semihosting_cmdline);
+		arm->semihosting_cmdline = cmdline;
+	}
+
+	return ERROR_OK;
+}
+
 static const struct command_registration arm_exec_command_handlers[] = {
 	{
 		.name = "reg",
@@ -1133,6 +1169,13 @@ static const struct command_registration arm_exec_command_handlers[] = {
 		.usage = "['enable'|'disable']",
 		.help = "activate support for semihosting operations",
 	},
+	{
+		"semihosting_cmdline",
+		.handler = handle_arm_semihosting_cmdline,
+		.mode = COMMAND_EXEC,
+		.usage = "arguments",
+		.help = "command line arguments to be passed to program",
+	},
 	{
 		"semihosting_fileio",
 		.handler = handle_arm_semihosting_fileio_command,