When expert configuration option(CONFIG_EXPERT) is enabled, menuconfig
offers a choice of compression algorithm to compress initial ramfs image;
This choice is stored into CONFIG_RD_* variables.  But usr/Makefile uses
earlier INITRAMFS_COMPRESSION_* macros to build initial ramfs file.  Since
none of them is defined, resulting 'initramfs_data.cpio' file remains
un-compressed.

This patch updates the Makefile to use CONFIG_RD_* variables and adds
support for LZ4 compression algorithm.  Also updates the
'gen_initramfs_list.sh' script to check whether a selected compression
command is accessible or not.  And fall-back to default gzip(1)
compression when it is not.
Signed-off-by: NP J P <prasad@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Replace bashisms with POSIX-compatible shell scripting.

Notably, de-duplicate '/' using a sed command from elsewhere in the same script
rather than "${name//\/\///}".

Commit by Jamey Sharp and Josh Triplett.
Signed-off-by: NJamey Sharp <jamey@minilop.net>
Signed-off-by: NJosh Triplett <josh@joshtriplett.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

gen_init_cpio gets the current time and uses it for each symlink,
special file, and directory.  Grab the current time once and make it
possible to override it with the KBUILD_BUILD_TIMESTAMP variable for
reproducible builds.
Signed-off-by: NMichal Marek <mmarek@suse.cz>

The timestamps recorded in the .gz files add no value.
Signed-off-by: NMichal Marek <mmarek@suse.cz>

Fixes generated by 'codespell' and manually reviewed.
Signed-off-by: NLucas De Marchi <lucas.demarchi@profusion.mobi>

This implements the API defined in <linux/decompress/generic.h> which is
used for kernel, initramfs, and initrd decompression.  This patch together
with the first patch is enough for XZ-compressed initramfs and initrd;
XZ-compressed kernel will need arch-specific changes.

The buffering requirements described in decompress_unxz.c are stricter
than with gzip, so the relevant changes should be done to the
arch-specific code when adding support for XZ-compressed kernel.
Similarly, the heap size in arch-specific pre-boot code may need to be
increased (30 KiB is enough).

The XZ decompressor needs memmove(), memeq() (memcmp() == 0), and
memzero() (memset(ptr, 0, size)), which aren't available in all
arch-specific pre-boot environments.  I'm including simple versions in
decompress_unxz.c, but a cleaner solution would naturally be nicer.
Signed-off-by: NLasse Collin <lasse.collin@tukaani.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Alain Knaff <alain@knaff.lu>
Cc: Albin Tonnerre <albin.tonnerre@free-electrons.com>
Cc: Phillip Lougher <phillip@lougher.demon.co.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add the necessary parts to be enable the use of LZO-compressed initramfs
build into the kernel.
Signed-off-by: NAlbin Tonnerre <albin.tonnerre@free-electrons.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Michal Marek <mmarek@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Expand the dependency set used for the initrd to include the
CONFIG_INITRAMFS_SOURCE file and the generator script itself.
Otherwise changing the initramfs file list does not rebuild the CPIO.
Signed-off-by: NJason Gunthorpe <jgunthorpe@obsidianresearch.com>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

When gen_initramfs_list is used to generate make dependencies, it
includes symbolic links, for which make tracks the link target. Any
change to that target will cause an initramfs rebuild, even if the
symlink points to something outside of the initramfs directory.

If the target happens to be /tmp, the rebuild occurs for each kernel
build, since gen_initramfs_list uses mktemp...

Proposed way to fix it is to omit symbolic links from generated
dependencies, but this has a small drawback: changing perm/owner on a
symlink will go unnoticed.
Signed-off-by: NMaxime Bizon <mbizon@freebox.fr>
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

Impact: Bugfix, silent build failures

Fix a bug in gen_initramfs_list.sh: in case of failure, it left an
empty output file behind, messing up the next make.
Signed-off-by: NAlain Knaff <alain@knaff.lu>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

Impact: Resolves build failures in some configurations

Makes it possible to disable CONFIG_RD_GZIP . In that case, the
built-in initramfs will be compressed by whatever compressor is
available (bzip2 or lzma) or left uncompressed if none is available.

It also removes a couple of warnings which occur when no ramdisk
compression at all is chosen.

It also restores the select ZLIB_INFLATE in drivers/block/Kconfig
which somehow came missing. This is needed to activate compilation of
the stuff in zlib_deflate.
Signed-off-by: NAlain Knaff <alain@knaff.lu>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

On a Mac OS X machine the output of ls -l is different from a standard
Linux machine. Use readlink instead of parsing a hardcoded field number
from the ls output.
Signed-off-by: NFelix Fietkau <nbd@openwrt.org>
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

Sometimes it is useful to squash all uid's/gid's to 0:0 regardless of
current owner.  For example, in build systems that get run as arbitrary
users (uClinux-dist).  This adds a special "squash" keyword so you can do
'-g squash -u squash' and have ownership squashed to root.
Signed-off-by: NMike Frysinger <vapier@gentoo.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

If the find(1) in scripts/gen_initramfs_list.sh generates any errors, it
will cause gen_initramfs_list.sh to fail (because of "set -e"), however
the errors from find are not printed to the user. This is rather confusing:

~/src/powerpc$ make O=~/build/powerpc-cell32/
make[2]: *** [usr/initramfs_data.cpio.gz] Error 1
make[1]: *** [usr] Error 2
make[1]: *** Waiting for unfinished jobs....
make[1]: *** wait: No child processes.  Stop.
make: *** [_all] Error 2

It is much easier to work out what the problem is if we let the errors
from find hit the console, eg:

~/src/powerpc$ make O=~/build/powerpc-cell32/
find: /home/michael/initramfs-source/home: Permission denied
find: /home/michael/initramfs-source/lost+found: Permission denied
find: /home/michael/initramfs-source/opt: Permission denied
find: /home/michael/initramfs-source/root: Permission denied
make[2]: *** [usr/initramfs_data.cpio.gz] Error 1
make[1]: *** [usr] Error 2
make[1]: *** Waiting for unfinished jobs....
make[1]: *** wait: No child processes.  Stop.
make: *** [_all] Error 2
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

Make kbuild handle compressed cpio initramfs-es.  An already compressed
cpio is copied directly to usr/, while a non-compressed cpio is filtered
through gzip (no changes here) on its way to usr/.

If the user has created a compressed cpio by other means, this saves him
from uncompressing it, just to be compressed again by kbuild.
Signed-off-by: NAlex Landau <landau.alex@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

  Replacing overhead of using some (external) programs
  instead of good old `sh'.

Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: William Stearns <wstearns@pobox.com>
Cc: Martin Schlemmer <azarah@nosferatu.za.org>
Signed-off-by: NOleg Verych <olecom@flower.upol.cz>
Acked-by: NMark Lord <lkml@rtr.ca>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix bug 7401.

Handle more than one source dir or file list to the initramfs gen scripts.

The Kconfig help for INITRAMFS_SOURCE claims that you can specify multiple
space-separated sources in order to allow unprivileged users to build an
image.  There are two bugs in the current implementation that prevent this
from working.

First, we pass "file1 dir2" to the gen_initramfs_list.sh script, which it
obviously can't open.

Second, gen_initramfs_list.sh -l outputs multiple definitions for
deps_initramfs -- one for each argument.
Signed-off-by: NThomas Chou <thomas@wytron.com.tw>
Cc: Sam Ravnborg <sam@ravnborg.org>
Acked-by: NMatthew Wilcox <matthew@wil.cx>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Create correct dependencies when specifying your own file with
list of files etc. to include in initramfs.
Reported by: Andre Noll <maan@skl-net.de>
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

initramfs.cpio.gz being build in usr/ and included in the
kernel was not rebuild when the included files changed.

To fix this the following was done:
- let gen_initramfs.sh generate a list of files and directories included
  in the initramfs
- gen_initramfs generate the gzipped cpio archive so we could simplify
  the kbuild file (Makefile)
- utilising the kbuild infrastructure so when uid/gid root mapping changes
  the initramfs will be rebuild

With this change we have a much more robust initramfs generation.
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!