util/amdfwtool/amdfwread: Fix incorrect option index

index I/O argument to getopt_long is not the index to argv. Instead it
is an index into the optlong array corresponding to the parsed option.
Also getopt() uses a global variable optind to track the index of the
next argument to be processed. Use the optindex variable as an index to
extract the filename from argv.

BUG=None
TEST=Build and use amdfwread to read the Soft-fuse bits from Guybrush
BIOS image. Observed no changes before and after the changes.

Change-Id: I33c74a0c8e12c5af76954524cf7294b7541d286b
Signed-off-by: Karthikeyan Ramasubramanian <kramasub@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/66553
Reviewed-by: Robert Zieba <robertzieba@google.com>
Reviewed-by: Raul Rangel <rrangel@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

1 files changed, 5 insertions, 6 deletions

diff --git a/util/amdfwtool/amdfwread.c b/util/amdfwtool/amdfwread.c
index 1a95c5c2677a..c9da3d883d96 100644
--- a/util/amdfwtool/amdfwread.c
+++ b/util/amdfwtool/amdfwread.c
@@ -179,19 +179,18 @@ int main(int argc, char **argv)
 	char *fw_file = NULL;
 
 	int selected_functions = 0;
-	int index = 0;
 	while (1) {
-		int opt = getopt_long(argc, argv, optstring, long_options, &index);
+		int opt = getopt_long(argc, argv, optstring, long_options, NULL);
 
 		if (opt == -1) {
-			index++;
-			if (index >= argc) {
-				/* Print usage if we didn't get any arguments */
+			if (optind != (argc - 1)) {
+				/* Print usage if one and only one option i.e. filename is
+				   not found. */
 				print_usage();
 				return 0;
 			}
 
-			fw_file = argv[index];
+			fw_file = argv[optind];
 			break;
 		}