xref: /aosp_15_r20/external/squashfs-tools/RELEASE-READMEs/README-3.0 (revision 79398b2563bcbbbab54656397863972d8fa68df1)
1*79398b25SAndroid Build Coastguard Worker	SQUASHFS 3.0 - A squashed read-only filesystem for Linux
2*79398b25SAndroid Build Coastguard Worker
3*79398b25SAndroid Build Coastguard Worker	Copyright 2002-2006 Phillip Lougher <[email protected]>
4*79398b25SAndroid Build Coastguard Worker
5*79398b25SAndroid Build Coastguard Worker	Released under the GPL licence (version 2 or later).
6*79398b25SAndroid Build Coastguard Worker
7*79398b25SAndroid Build Coastguard WorkerWelcome to the first release of Squashfs version 3.0.  Squashfs 3.0 has the
8*79398b25SAndroid Build Coastguard Workerthe following improvements to 2.x.
9*79398b25SAndroid Build Coastguard Worker
10*79398b25SAndroid Build Coastguard Worker	1. Filesystems are no longer limited to 4 GB.  In
11*79398b25SAndroid Build Coastguard Worker	   theory 2^64 or 4 exabytes is now supported.
12*79398b25SAndroid Build Coastguard Worker
13*79398b25SAndroid Build Coastguard Worker	2. Files are no longer limited to 4 GB.  In theory the maximum
14*79398b25SAndroid Build Coastguard Worker	   file size is 4 exabytes.
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16*79398b25SAndroid Build Coastguard Worker	3. Metadata (inode table and directory tables) are no longer
17*79398b25SAndroid Build Coastguard Worker	   restricted to 16 Mbytes.
18*79398b25SAndroid Build Coastguard Worker
19*79398b25SAndroid Build Coastguard Worker	4. Hardlinks are now suppported.
20*79398b25SAndroid Build Coastguard Worker
21*79398b25SAndroid Build Coastguard Worker	5. Nlink counts are now supported.
22*79398b25SAndroid Build Coastguard Worker
23*79398b25SAndroid Build Coastguard Worker	6. Readdir now returns '.' and '..' entries.
24*79398b25SAndroid Build Coastguard Worker
25*79398b25SAndroid Build Coastguard Worker	7. Special support for files larger than 256 MB has been added to
26*79398b25SAndroid Build Coastguard Worker	   the Squashfs kernel code for faster read access.
27*79398b25SAndroid Build Coastguard Worker
28*79398b25SAndroid Build Coastguard Worker	8. Inode numbers are now stored within the inode rather than being
29*79398b25SAndroid Build Coastguard Worker	   computed from inode location on disk (this is not so much an
30*79398b25SAndroid Build Coastguard Worker	   improvement, but a change forced by the previously listed
31*79398b25SAndroid Build Coastguard Worker	   improvements).
32*79398b25SAndroid Build Coastguard Worker
33*79398b25SAndroid Build Coastguard WorkerThere is a new Unsquashfs utility (in squashfs-tools) than can be used to
34*79398b25SAndroid Build Coastguard Workerdecompress a filesystem without mounting it.
35*79398b25SAndroid Build Coastguard Worker
36*79398b25SAndroid Build Coastguard WorkerSquashfs 3.0 supports 2.x filesystems.  Support for 1.x filesystems
37*79398b25SAndroid Build Coastguard Workerwill be added in the future.
38*79398b25SAndroid Build Coastguard Worker
39*79398b25SAndroid Build Coastguard Worker1. UNSQUASHFS
40*79398b25SAndroid Build Coastguard Worker-------------
41*79398b25SAndroid Build Coastguard Worker
42*79398b25SAndroid Build Coastguard WorkerUnsquashfs has the following options:
43*79398b25SAndroid Build Coastguard Worker
44*79398b25SAndroid Build Coastguard WorkerSYNTAX: unsquashfs [-ls | -dest] filesystem
45*79398b25SAndroid Build Coastguard Worker	-version		print version, licence and copyright information
46*79398b25SAndroid Build Coastguard Worker	-info			print files as they are unsquashed
47*79398b25SAndroid Build Coastguard Worker	-ls			list filesystem only
48*79398b25SAndroid Build Coastguard Worker	-dest <pathname>	unsquash to <pathname>, default "squashfs-root"
49*79398b25SAndroid Build Coastguard Worker
50*79398b25SAndroid Build Coastguard WorkerThe "-ls" option can be used to list the contents of a filesystem without
51*79398b25SAndroid Build Coastguard Workerdecompressing the filesystem data itself.
52*79398b25SAndroid Build Coastguard Worker
53*79398b25SAndroid Build Coastguard WorkerThe "-info" option forces Unsquashfs to print each file as it is decompressed.
54*79398b25SAndroid Build Coastguard Worker
55*79398b25SAndroid Build Coastguard WorkerThe "-dest" option specifies the directory that is used to decompress
56*79398b25SAndroid Build Coastguard Workerthe filesystem data.  If this option is not given then the filesystem is
57*79398b25SAndroid Build Coastguard Workerdecompressed to the directory "squashfs-root" in the current working directory.
58*79398b25SAndroid Build Coastguard Worker
59*79398b25SAndroid Build Coastguard WorkerUnsquashfs can decompress 3.0 filesystems.  Support for 2.x and 1.x
60*79398b25SAndroid Build Coastguard Workerfilesystems will be added in the future.
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