To configure the Linux kernel, we currently provide two options:
1. Passing a defconfig name (for example "multi_v7"), to which we append
"_defconfig" to run "make multi_v7_defconfig".
2. Passing a path to a custom configuration file.
Unfortunately, those two possibilities do not allow to configure the
kernel when you want to use the default configuration built into the
kernel for a given architecture. For example, on ARM64, there is a
single defconfig simply called "defconfig", which you can load by
running "make defconfig".
Using the mechanism (1) above doesn't work because we append
"_defconfig" automatically.
One solution would be to change (1) and require the user to enter the
full defconfig named (i.e "multi_v7_defconfig" instead of "multi_v7"),
but we would break all existing Buildroot configurations.
So instead, we add a third option, which simply tells Buildroot to use
the default configuration for the selected architecture. In this case,
Buildroot will configure the kernel by running "make defconfig".
Cc: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
When setting BR2_LINUX_KERNEL_LATEST_VERSION, it is hard for the user to
know that this version is subject to change in the future.
Explicit this in the Kconfig entry text.
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Acked-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Since quite some time, the kernel and bootloader communities consider
zImage as the default format for kernel images on ARM, replacing
uImage. The load address information in uImage is no longer needed,
since the kernel is position-independent in terms of physical address,
except on a few old platforms. For most people, using zImage is simply
better/simpler, so let's switch to zImage as the default image format
on ARM.
All defconfigs are updated: 46 defconfigs no longer need to select
explicitly zImage because it's the default, and 16 defconfigs now need
to explicitly select uImage because that's no longer the default.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Reviewed-by: Matt Weber <matt@thewebers.ws>
Acked-by: Julien Boibessot <julien.boibessot@armadeus.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
It is no longer meaningful, now that we have the option to use the
kernel version for the linux headers, as it is more logical and more
versatile.
Add it to legacy.
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Peter Korsgaard <peter@korsgaard.com>
Cc: Arnout Vandecappelle <arnout@mind.be>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Some heavily (and most often improperly) modified Linux kernels may export
new APIs to userland, so as to speak to custom hardware or custom kernel
facilities.
However, we currently have no easy way to use such kernels as a source
for the linux-headers package, which precludes having those userland
headers intalled for userland applications to use them.
We do have a way for the kernel to use the same version as for the
headers, but that is definitely not enough, as the linux-headers package
has a version choice that is far less versatile and capable than that of
the linux package.
Add a new option for the linux-headers package, for the user to specify
that the version (really, the sources) of the kernel be used to install
the headers from.
We do that by making linux-headers patch-depend on the linux package.
We can't have linux-header simply depend on linux, because the simple
dependency means the the dependee will be configured, built and installed
before the dependent is configured. And since linux is a target package,
it depends on the toolchain, which internally dependes on linux-headers,
which would depend on linux, and we'd get a circular dependency.
Using patch-depend will ensure that linux is extracted and patched
before linux-headers is extracted, which is really all we need.
Then, we install the headers from the linux source tree, rather than
from linux-headers' source tree (as there's nothing in there!).
Since we need to install a private set for uClibc (see cde947f, uclibc:
prevent rebuilding after installation to staging), we explicitly set
INSTALL_HDR_PATH when calling the kernel' install-headers rule in
LINUX_HEADERS_CONFIGURE_CMDS, so that the headers are installed in
linux-headers' $(@D) instead of linux' $(@D).
Finally, as there is no way to know the kernel version in this case, we
must still prompt the user for the kernel series the headers are from
(like we do for a custom version) and check for consistency at build
time.
Note however that this still leaves users that want to built their
such-kernel outside of Buildroot out in the cold.
[Peter: drop comment as suggested by Thomas]
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Karoly Kasza <kaszak@gmail.com>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Peter Korsgaard <jacmet@uclibc.org>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
Currently, packages that need the kernel to have support for laodable
modules have two ways to require it:
- either the use the kernel-module infra, which does it automatically,
- or they do not use it, and they need to require it manually by
setting the corresponding Makefile variable; however, they must only
set it when they are actually enabled, which makes for a slightly
cumbersome and ugly code, like:
ifeq ($(BR2_PACKAGE_FOO),y)
LINUX_NEEDS_MODULES = y
endif
Introduce a new blind Kconfig option that packages can select to signify
they need kernel modules. That Kconfig option is then used to set the
Makefile variable.
It makes it cleaner:
- code is simpler (one Kconfig line instead of a Makefile if-block,
- this is handled at the Kconfig level, which is where we usually
handle such dependencies.
Packages will be updated in follow-up commits.
Reported-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
Linux for MIPS supports raw binary zboot image (vmlinuz.bin).
Add it to the "Kernel binary format" list.
Signed-off-by: Yegor Yefremov <yegorslists@googlemail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
This selection will ensure that the correct host tools
will be build used for the kernel compression method used.
[Maxime: Select the compression opts in the kernel config too ]
Signed-off-by: Sagaert Johan <sagaert.johan@proximus.be>
Signed-off-by: Maxime Hadjinlian <maxime.hadjinlian@gmail.com>
Reviewed-by: "Yann E. MORIN" <yann.morin.1998 at free.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
On aarch64, the image name is always Image, so let's add support for
that.
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
This patch is based on the patch send by James Knight:
http://lists.busybox.net/pipermail/buildroot/2015-May/128754.html
Signed-off-by: Romain Naour <romain.naour@openwide.fr>
Cc: James Knight <james.knight@rockwellcollins.com>
Reviewed-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
