diff -Naur squashfs4.3/squashfs-tools/mksquashfs.c squashfs4.3-bak/squashfs-tools/mksquashfs.c
--- squashfs4.3/squashfs-tools/mksquashfs.c	2014-05-13 06:18:20.000000000 +0800
+++ squashfs4.3-bak/squashfs-tools/mksquashfs.c	2018-08-24 14:48:35.268576971 +0800
@@ -129,6 +129,9 @@
 /* inode lookup table */
 squashfs_inode *inode_lookup_table = NULL;

+/* override all timestamps */
+time_t fixed_time = -1;
+
 /* in memory directory data */
 #define I_COUNT_SIZE		128
 #define DIR_ENTRIES		32
@@ -2265,7 +2268,8 @@
			pathname_reader(dir_ent), strerror(errno));
		goto read_err;
	}
-
+	if (fixed_time != -1)
+		buf2.st_mtime = fixed_time;
	if(read_size != buf2.st_size) {
		close(file);
		memcpy(buf, &buf2, sizeof(struct stat));
@@ -3139,7 +3143,7 @@
		buf.st_mode = S_IRWXU | S_IRWXG | S_IRWXO | S_IFDIR;
		buf.st_uid = getuid();
		buf.st_gid = getgid();
-		buf.st_mtime = time(NULL);
+		buf.st_mtime = fixed_time != -1 ? fixed_time : time(NULL);
		buf.st_dev = 0;
		buf.st_ino = 0;
		dir_ent->inode = lookup_inode2(&buf, PSEUDO_FILE_OTHER, 0);
@@ -3148,6 +3152,8 @@
			/* source directory has disappeared? */
			BAD_ERROR("Cannot stat source directory %s because %s\n",
				pathname, strerror(errno));
+		if(fixed_time != -1)
+			buf.st_mtime = fixed_time;
		dir_ent->inode = lookup_inode(&buf);
	}

@@ -3370,6 +3376,8 @@
			free_dir_entry(dir_ent);
			continue;
		}
+		if(fixed_time != -1)
+			buf.st_mtime = fixed_time;

		if((buf.st_mode & S_IFMT) != S_IFREG &&
					(buf.st_mode & S_IFMT) != S_IFDIR &&
@@ -3526,7 +3534,7 @@
		buf.st_gid = pseudo_ent->dev->gid;
		buf.st_rdev = makedev(pseudo_ent->dev->major,
			pseudo_ent->dev->minor);
-		buf.st_mtime = time(NULL);
+		buf.st_mtime = fixed_time != -1 ? fixed_time : time(NULL);
		buf.st_ino = pseudo_ino ++;

		if(pseudo_ent->dev->type == 'd') {
@@ -5076,6 +5084,15 @@
			force_progress = TRUE;
		else if(strcmp(argv[i], "-no-exports") == 0)
			exportable = FALSE;
+		else if(strcmp(argv[i], "-fixed-time") == 0) {
+			if((++i == argc) || (fixed_time =
+					strtoll(argv[i], &b, 10), *b != '\0')) {
+				ERROR("%s: -fixed-time missing or invalid "
+					"timestamp\n", argv[0]);
+
+				exit(1);
+			}
+		}
		else if(strcmp(argv[i], "-processors") == 0) {
			if((++i == argc) || !parse_num(argv[i], &processors)) {
				ERROR("%s: -processors missing or invalid "
@@ -5717,7 +5734,7 @@
	sBlk.flags = SQUASHFS_MKFLAGS(noI, noD, noF, noX, no_fragments,
		always_use_fragments, duplicate_checking, exportable,
		no_xattrs, comp_opts);
-	sBlk.mkfs_time = time(NULL);
+	sBlk.mkfs_time = fixed_time != -1 ? fixed_time : time(NULL);

	disable_info();