mkimage: Allow updating the FIT timestamp

Normally the FIT timestamp is created the first time mkimage is run on a
FIT, when converting the source .its to the binary .fit file. This
corresponds to using the -f flag. But if the original input to mkimage is
a binary file (already compiled) then the timestamp is assumed to have
been set previously.

Add a -t flag to allow setting the timestamp in this case.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

tools/fit_image.c

@@ -53,7 +53,7 @@ static int fit_add_file_data(struct image_tool_params *params, size_t size_inc,
 	}
 
 	/* for first image creation, add a timestamp at offset 0 i.e., root  */
-	if (params->datafile) {
+	if (params->datafile || params->reset_timestamp) {
 		time_t time = imagetool_get_source_date(params->cmdname,
 							sbuf.st_mtime);
 		ret = fit_set_timestamp(ptr, 0, time);

tools/imagetool.h

@@ -81,6 +81,7 @@ struct image_tool_params {
 	unsigned int external_offset;	/* Add padding to external data */
 	int bl_len;		/* Block length in byte for external data */
 	const char *engine_id;	/* Engine to use for signing */
+	bool reset_timestamp;	/* Reset the timestamp on an existing image */
 };
 
 /*

tools/mkimage.c

@@ -145,7 +145,7 @@ static void process_args(int argc, char **argv)
 	int opt;
 
 	while ((opt = getopt(argc, argv,
-			     "a:A:b:B:c:C:d:D:e:Ef:Fk:i:K:ln:N:p:O:rR:qsT:vVx")) != -1) {
+		   "a:A:b:B:c:C:d:D:e:Ef:Fk:i:K:ln:N:p:O:rR:qstT:vVx")) != -1) {
 		switch (opt) {
 		case 'a':
 			params.addr = strtoull(optarg, &ptr, 16);
@@ -269,6 +269,9 @@ static void process_args(int argc, char **argv)
 		case 's':
 			params.skipcpy = 1;
 			break;
+		case 't':
+			params.reset_timestamp = 1;
+			break;
 		case 'T':
 			if (strcmp(optarg, "list") == 0) {
 				show_valid_options(IH_TYPE);