--- a/target-utils/simagent/stringarg.c	Fri Mar 12 23:36:46 2021 +0000
+++ b/target-utils/simagent/stringarg.c	Fri Mar 12 23:58:15 2021 +0000
@@ -30,14 +30,15 @@
 			break;
 		if (!isxdigit(arg[0]) || !isxdigit(arg[1])) {
 			printf("ERROR: invalid hex string input\n");
-			return;
+			return(-1);
 		}
 		if (count >= maxlen) {
 			printf("ERROR: hex string input is too long\n");
-			return;
+			return(-1);
 		}
 		buf[count++] = (decode_hex_digit(arg[0]) << 4) |
 				decode_hex_digit(arg[1]);
+		arg += 2;
 	}
 	return count;
 }