The kernel being a component that often needs a fairly important set
of changes to be adapted to a particular hardware platform, having
maximum flexibility on the patching process is a nice
thing. Therefore, as per the discussions from the Buildroot Developer
Day, we add a mechanism to apply a list of patches (that could come
either from URLs, local files or local directories).
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
Now that minimal kernel defconfigs are used in Buildroot, the problem
is that copying those minimal configuration files to .config in the
kernel source tree does not work, as kconfig will ask interactively
what should be the value for all unspecified options.
On suggestion on Sam Ravnborg, the easiest way to solve this is to
import the minimal defconfig file as a defconfig inside the kernel
tree (in arch/$(ARCH)/configs) and configure the kernel with it.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
The linux.mk rewrite lost the DEPMOD setting while installing modules
which means depending on host-module-init-tools has been useless.
Instead, the build system has been executing /sbin/depmod.
While we're here, drop the INSTALL_MOD_PATH since LINUX26_MAKE_FLAGS
already contains it.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Acked-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
We only have one Linux kernel package, and "linux26-" is an anachronism
in today's world. So add useful "linux-%" shortcuts to the "linux26-%".
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Acked-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
Building with linux-2.6.36 and initramfs support causes the build to
pause while it prompts for newer options (uid/gid/compression). So
have the build system inject the newer options into the linux config
automatically. Older versions should just ignore these.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Acked-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
The current linux code overrides LDFLAGS that the kernel itself might be
setting up. Looking at the history, there doesn't seem to be any reason
for this override. It was added in ea8b1fa6a6 without any logic.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Acked-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
Linux has been using "usr/initramfs_data.cpio" for a few releases as the
generated cpio name, so the buildroot match of "...cpio.*" won't actually
clean out the previous result.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Acked-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
And all the infrastructure surrounding it. A broken sed implementation
is quite rare nowadays, as seen by the fact that the current host-sed
support has been broken for a while, so just get rid of it.
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
On most architectures, the kernel image can be found in
arch/<ARCH>/boot, but on AVR32, it's in arch/<ARCH>/boot/images.
Issue initially reported by Joachim Pihl
<joachim.pihl@sensordevelopments.com>.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Some Linux kernel output image formats are available on some archs,
some not. For example 'uImage' is not supported on MIPS, so let's
prevent the user from making this selection.
Issue initially reported by Choi, David <David.Choi@Micrel.Com>.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
When initramfs was not selected as a root filesystem, we forcefully
disabled the initramfs in the kernel configuration.
However, it prevents an user from manually managing its initramfs, as
we override the option he has set in his kernel configuration
file. There's no real reason to do so: when initramfs is not selected
as the root filesystem, just don't touch initramfs related options in
the kernel configuration.
Problem reported by Sergey Naumov <sknaumov@gmail.com>.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
Just as we do for U-Boot, error out in the Linux kernel makefile when
the defconfig name or the configuration file path are not
correct. What prompted me to implement this was a report on IRC from
an user using BR 2010.05 and not understand why the kernel build
process was failing. It was because he just forgot to set the path of
the configuration file.
Of course, it doesn't catch all mistakes (like pointing to a
non-existing defconfig or to a non-existing configuration file), but
it at least catches basic mistakes.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
In Buildroot, the kernel is built and installed *before* the root
filesystems are built. This allows the root filesystem to correctly
contain the kernel modules that have been installed.
However, in the initramfs case, the root filesystem is part of the
kernel. Therefore, the kernel should be built *after* the root
filesystem (which, in the initramfs case simply builds a text file
listing all files/directories/devices/symlinks that should be part of
the initramfs). However, this isn't possible as the initramfs text
file would lack all kernel modules.
So, the solution choosen here is to keep the normal order: kernel is
built before the root filesystem is generated, and to add a little
quirk to retrigger a kernel compilation after the root filesystem
generation.
To do so, we add a ROOTFS_$(FSTYPE)_POST_TARGETS variable to the
fs/common.mk infrastructure. This allows individual filesystems to set
a target name that we should depend on *after* generating the root
filesystem itself (contrary to normal ROOTFS_$(FSTYPE)_DEPENDENCIES,
on which we depend *before* generating the root filesystem).
The initramfs code in fs/initramfs/initramfs.mk uses this to add a
dependency on 'linux26-rebuild-with-initramfs'.
In linux/linux.mk, we do various things :
* If BR2_TARGET_ROOTFS_INITRAMFS is enabled (i.e if initramfs is
enabled as a root filesystem type), then we create an empty
rootfs.initramfs file (remember that at this point, the root
filesystem hasn't been generated) and we adjust the kernel
configuration to include an initramfs. Of course, in the initial
kernel build, this initramfs will be empty.
* In the linux26-rebuild-with-initramfs target, we retrigger a
compilation of the kernel image, after removing the initramfs in
the kernel sources to make sure it gets properly rebuilt (we've
experienced cases were modifying the rootfs.initramfs file wouldn't
retrigger the generation of the initramfs at the kernel level).
This is fairly quirky, but initramfs really is a special case, so in
one way or another, we need a little quirk to solve its specialness.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
These targets allow the user to customize the configuration of the
Linux kernel. After changing the kernel configuration, the next time
the user runs "make", the kernel is rebuilt to take into account the
new configuration (not rebuilt from scratch).
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
We only adjust the configuration or ARM EABI and IPv6. The (more
complicated) initramfs case is handled in a separate commit. The user
is expected to take care of all other configuration details (like
having Netfilter enabled to make iptables work, etc.)
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
In order to not depend on module init tools being installed on the
development environment of the Buildroot user, let's build module init
tools for the host.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
This patch introduces a single, simple, infrastructure to build the
Linux kernel. The configuration is limited to :
* Kernel version: a fixed recent stable version, same as kernel
headers version (for internal toolchains only), custom stable
version, or custom tarball URL
* Kernel patch: either a local file, directory or an URL
* Kernel configuration: either the name of a defconfig or the
location of a custom configuration file
* Kernel image: either uImage, bzImage, zImage or vmlinux.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
