[U-Boot] [RFC PATCH 39/44] mkimage: Add -c option to specify a comment for key signing

[Simon Glass]

When signing an image, it is useful to add some details about which tool
or person is authorising the signing. Add a comment field which can take
care of miscellaneous requirements.

Signed-off-by: Simon Glass <sjg at chromium.org>
---
 doc/mkimage.1     |    6 ++++++
 tools/fit_image.c |    2 +-
 tools/mkimage.c   |    8 +++++++-
 tools/mkimage.h   |    1 +
 4 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/doc/mkimage.1 b/doc/mkimage.1
index f9c733a..b67a351 100644
--- a/doc/mkimage.1
+++ b/doc/mkimage.1
@@ -97,6 +97,12 @@ Set XIP (execute in place) flag.
 .B Create FIT image:
 
 .TP
+.BI "\-c [" "comment" "]"
+Specifies a comment to be added when signing. This is typically a useful
+message which describes how the image was signed or some other useful
+information.
+
+.TP
 .BI "\-D [" "dtc options" "]"
 Provide special options to the device tree compiler that is used to
 create the image.
diff --git a/tools/fit_image.c b/tools/fit_image.c
index 835d2fb..82f1597 100644
--- a/tools/fit_image.c
+++ b/tools/fit_image.c
@@ -153,7 +153,7 @@ static int fit_handle_file (struct mkimage_params *params)
 
 	/* set hashes for images in the blob */
 	if (fit_add_verification_data(params->keydir,
-			dest_blob, ptr, NULL, 0)) {
+			dest_blob, ptr, params->comment, 0)) {
 		fprintf (stderr, "%s Can't add hashes to FIT blob",
 				params->cmdname);
 		goto err_add_hashes;
diff --git a/tools/mkimage.c b/tools/mkimage.c
index 99787d9..d6e47a5 100644
--- a/tools/mkimage.c
+++ b/tools/mkimage.c
@@ -183,6 +183,11 @@ main (int argc, char **argv)
 					genimg_get_arch_id (*++argv)) < 0)
 					usage ();
 				goto NXTARG;
+			case 'c':
+				if (--argc <= 0)
+					usage();
+				params.comment = *++argv;
+				goto NXTARG;
 			case 'C':
 				if ((--argc <= 0) ||
 					(params.comp =
@@ -636,7 +641,8 @@ usage ()
 			 "          -x ==> set XIP (execute in place)\n",
 		params.cmdname);
 	fprintf(stderr, "       %s [-k keydir] [-K dtb] [-D dtc_options]"
-			" [-f fit-image.its|-F] fit-image\n", params.cmdname);
+			" [ -c <comment>] [-f fit-image.its|-F] fit-image\n",
+			params.cmdname);
 	fprintf (stderr, "       %s -V ==> print version information and exit\n",
 		params.cmdname);
 
diff --git a/tools/mkimage.h b/tools/mkimage.h
index 41bec21..4391ca8 100644
--- a/tools/mkimage.h
+++ b/tools/mkimage.h
@@ -77,6 +77,7 @@ struct mkimage_params {
 	char *cmdname;
 	const char *keydir;	/* Directory holding private keys */
 	const char *keydest;	/* Destination .dtb for public key */
+	const char *comment;	/* Comment to add to signature node */
 };
 
 /*
-- 
1.7.7.3