Add a proper help message with examples on how to use this tool.

Signed-off-by: Shreenidhi Shedi <yesshedi@gmail.com>
---
 scripts/sign-file.c | 48 ++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 41 insertions(+), 7 deletions(-)

diff --git a/scripts/sign-file.c b/scripts/sign-file.c
index 0a275256ca16..d3abc5721a7e 100644
--- a/scripts/sign-file.c
+++ b/scripts/sign-file.c
@@ -74,12 +74,43 @@ struct module_signature {
 static char magic_number[] = "~Module signature appended~\n";
 
 static __attribute__((noreturn))
-void format(void)
+void print_usage(void)
 {
-	fprintf(stderr,
-		"Usage: scripts/sign-file [-dp] <hash algo> <key> <x509> <module> [<dest>]\n");
-	fprintf(stderr,
-		"       scripts/sign-file -s <raw sig> <hash algo> <x509> <module> [<dest>]\n");
+	fprintf(stderr, "Usage: scripts/sign-file [OPTIONS]... [MODULE]...\n");
+	fprintf(stderr, "Available options:\n");
+	fprintf(stderr, "-h, --help             Print this help message and exit\n");
+
+	fprintf(stderr, "\nOptional args:\n");
+	fprintf(stderr, "-s, --rawsig <sig>     Raw signature\n");
+	fprintf(stderr, "-p, --savesig          Save signature\n");
+	fprintf(stderr, "-d, --signonly         Sign only\n");
+#ifndef USE_PKCS7
+	fprintf(stderr, "-k, --usekeyid         Use key ID\n");
+#endif
+	fprintf(stderr, "-b, --bulksign         Sign modules in bulk\n");
+	fprintf(stderr, "-r, --replaceorig      Replace original\n");
+	fprintf(stderr, "-t, --dest <dest>      Destination path ");
+	fprintf(stderr, "(Exclusive with bulk option)\n");
+
+	fprintf(stderr, "\nMandatory args:\n");
+	fprintf(stderr, "-i, --privkey <key>    Private key\n");
+	fprintf(stderr, "-a, --hashalgo <alg>   Hash algorithm\n");
+	fprintf(stderr, "-x, --x509 <x509>      X509\n");
+
+	fprintf(stderr, "\nExamples:\n");
+
+	fprintf(stderr, "\n    Regular signing:\n");
+	fprintf(stderr, "     scripts/sign-file -a sha512 -i certs/signing_key.pem ");
+	fprintf(stderr, "-x certs/signing_key.x509 <module>\n");
+
+	fprintf(stderr, "\n    Signing with destination path:\n");
+	fprintf(stderr, "     scripts/sign-file -a sha512 -i certs/signing_key.pem ");
+	fprintf(stderr, "-x certs/signing_key.x509 <module> -t <path>\n");
+
+	fprintf(stderr, "\n    Signing modules in bulk:\n");
+	fprintf(stderr, "     scripts/sign-file -a sha512 -i certs/signing_key.pem ");
+	fprintf(stderr, "-x certs/signing_key.x509 -b <module1> <module2> ...\n");
+
 	exit(2);
 }
 
@@ -281,7 +312,7 @@ static void parse_args(int argc, char **argv, struct cmd_opts *opts)
 #endif
 
 		case 'h':
-			format();
+			print_usage();
 			break;
 
 		case 'i':
@@ -312,7 +343,7 @@ static void parse_args(int argc, char **argv, struct cmd_opts *opts)
 			break;
 
 		default:
-			format();
+			print_usage();
 			break;
 		}
 	} while (opt != -1);
@@ -472,6 +503,9 @@ int main(int argc, char **argv)
 	argc -= optind;
 	argv += optind;
 
+	if ((opts.bulk_sign && opts.dest_name) || (!opts.bulk_sign && argc != 1))
+		print_usage();
+
 	OpenSSL_add_all_algorithms();
 	ERR_load_crypto_strings();
 	ERR_clear_error();
-- 
2.41.0

On Wed, Aug 09, 2023 at 10:52:08PM +0530, Shreenidhi Shedi wrote:
> Add a proper help message with examples on how to use this tool.

This should be the first patch, right?  Then you can add the proper
documentation for the new features when you add them.

thanks,

greg k-h