2 * volume_id - reads filesystem label and uuid
4 * Copyright (C) 2012 S-G Bergh <sgb@systemasis.org>
6 * Licensed under GPLv2, see file LICENSE in this source tree.
9 //kbuild:lib-$(CONFIG_FEATURE_VOLUMEID_SQUASHFS) += squashfs.o
11 //config:config FEATURE_VOLUMEID_SQUASHFS
12 //config: bool "SquashFS filesystem"
14 //config: depends on VOLUMEID && FEATURE_BLKID_TYPE
16 //config: Squashfs is a compressed read-only filesystem for Linux. Squashfs is
17 //config: intended for general read-only filesystem use and in constrained block
18 //config: device/memory systems (e.g. embedded systems) where low overhead is
21 #include "volume_id_internal.h"
23 struct squashfs_superblock {
32 int FAST_FUNC volume_id_probe_squashfs(struct volume_id *id /*,uint64_t off*/)
34 #define off ((uint64_t)0)
35 struct squashfs_superblock *sb;
37 dbg("SquashFS: probing at offset 0x%llx", (unsigned long long) off);
38 sb = volume_id_get_buffer(id, off, 0x200);
42 // Old SquashFS (pre 4.0) can be both big and little endian, so test for both.
43 // Likewise, it is commonly used in firwmare with some non-standard signatures.
44 #define pack(a,b,c,d) ( (uint32_t)((a * 256 + b) * 256 + c) * 256 + d )
45 #define SIG1 pack('s','q','s','h')
46 #define SIG2 pack('h','s','q','s')
47 #define SIG3 pack('s','h','s','q')
48 #define SIG4 pack('q','s','h','s')
54 IF_FEATURE_BLKID_TYPE(id->type = "squashfs";)