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Valentine Barshak 391c82efa1 linux: Do not force GZIP initramfs compression
Initramfs compression does not make much sense for the architectures
that support compressed kernel images because in this case the data
would be compressed twice. This will eventually result in a bigger
kernel image and time overhead when uncompressing it.
The only reason to use compressed initramfs is to reduce memory
usage when the kernel prepares rootfs, and both the unpacked
filesystem and initramfs.cpio are present in the memory.

Buildroot attempts to force GZIP compression for initramfs,
however it doesn't always work because initramfs compression mode
depends on RAM disk compression supported by the kernel.
Thus, CONFIG_INITRAMFS_COMPRESSION_GZIP depends on CONFIG_RD_GZIP.
If CONFIG_RD_GZIP is not set, setting GZIP initramfs compression
will have no effect.

Besides, the kernel also supports other compression methods,
like BZIP2, LZMA, XZ and LZO. Forcing the good old GZIP does not
really make much sense any more.

This removes initramfs compression settings from Buildroot,
so that the default value preset in the kernel config is used,
which is CONFIG_INITRAMFS_COMPRESSION_NONE.

If initramfs compression is still needed, it can be set
in the kernel config (using make linux-menuconfig)

Signed-off-by: Valentine Barshak <gvaxon@gmail.com>
Acked-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
2013-07-08 14:50:31 +02:00
arch
board configs/qemu: bump relevant config versions 2013-07-08 08:30:44 +02:00
boot
configs configs/qemu: bump relevant config versions 2013-07-08 08:30:44 +02:00
docs website: remove dead udhcp link 2013-07-08 14:50:01 +02:00
fs linux: Do not force GZIP initramfs compression 2013-07-08 14:50:31 +02:00
linux linux: Do not force GZIP initramfs compression 2013-07-08 14:50:31 +02:00
package elf2flt: needs to link with zlib 2013-07-08 08:15:41 +02:00
support Add 'bc' in the mandatory dependencies 2013-07-05 15:30:43 +02:00
system system/permissions: make /root group+others non-writable 2013-06-23 21:51:57 +02:00
toolchain eglibc: enable support in the Buildroot toolchain backend 2013-07-04 11:08:27 +02:00
.defconfig
.gitignore
CHANGES
Config.in Remove BR2_HAVE_DEVFILES 2013-07-04 09:06:33 +02:00
Config.in.legacy elf2flt: convert to the package infrastructure 2013-07-03 22:09:12 +02:00
COPYING
Makefile Introduce BR2_TOOLCHAIN_USES_{UCLIBC, GLIBC} 2013-07-04 09:08:42 +02:00
Makefile.legacy

To build and use the buildroot stuff, do the following:

1) run 'make menuconfig'
2) select the packages you wish to compile
3) run 'make'
4) wait while it compiles
5) Use your shiny new root filesystem. Depending on which sort of
    root filesystem you selected, you may want to loop mount it,
    chroot into it, nfs mount it on your target device, burn it
    to flash, or whatever is appropriate for your target system.

You do not need to be root to build or run buildroot.  Have fun!

Offline build:
==============

In order to do an offline-build (not connected to the net), fetch all
selected source by issuing a
$ make source

before you disconnect.
If your build-host is never connected, then you have to copy buildroot
and your toplevel .config to a machine that has an internet-connection
and issue "make source" there, then copy the content of your dl/ dir to
the build-host.

Building out-of-tree:
=====================

Buildroot supports building out of tree with a syntax similar
to the Linux kernel. To use it, add O=<directory> to the
make command line, E.G.:

$ make O=/tmp/build

And all the output files (including .config) will be located under /tmp/build.

More finegrained configuration:
===============================

You can specify a config-file for uClibc:
$ make UCLIBC_CONFIG_FILE=/my/uClibc.config

And you can specify a config-file for busybox:
$ make BUSYBOX_CONFIG_FILE=/my/busybox.config

To use a non-standard host-compiler (if you do not have 'gcc'),
make sure that the compiler is in your PATH and that the library paths are
setup properly, if your compiler is built dynamically:
$ make HOSTCC=gcc-4.3.orig HOSTCXX=gcc-4.3-mine

Depending on your configuration, there are some targets you can use to
use menuconfig of certain packages. This includes:
$ make HOSTCC=gcc-4.3 linux-menuconfig
$ make HOSTCC=gcc-4.3 uclibc-menuconfig
$ make HOSTCC=gcc-4.3 busybox-menuconfig

Please feed suggestions, bug reports, insults, and bribes back to the
buildroot mailing list: buildroot@uclibc.org