Recompile kernel

Latest revision as of 23:23, 26 July 2011

This page explains the kernel recompilation process. There is also information on how to configure the MeeGo kernel. There already is a guide on how to compile the kernel for MeeGo, including links to packaging : Tips on compiling and packaging kernels in MeeGo.

Fetch the kernel source

The first thing you'll need to do to recompile the MeeGo kernel is to download and unpack the MeeGo kernel package. To get that package you can download it with wget like this;

wget http://repo.meego.com/MeeGo/releases/1.2.0/repos/oss/source/kernel-2.6.37.2-8.27.src.rpm

You can of course get your kernel directly from upstream at kernel.org for example or clone it from MeeGo's git repos ( https://meego.gitorious.org/meego-os-base/kernel-source )

git clone git://gitorious.org/meego-os-base/kernel-source.git

Unpack source rpm

If you take the packaged MeeGo kernel, then you'll need to unpack this rpm. You can do that this way :

rpm2cpio kernel-2.6.37.2-8.27.src.rpm | cpio -id

Modify source code

Your development work should be in the kernel source code directory, you may do the follow modification:

• If you want to add a patch, you need copy the patch to current directory and add this patch in spec file.
• If you wan to remove patches, you just need to remove them in spec file.
• If you want to modify exist patch, you can modify the special patch and spec file need not to modify.

Re-build kernel

Once you development work is done, you can use ‘build’ command to generate new RPM based on you changes. Command as follows:

   build \
    --repository http://repo.meego.com/MeeGo/releases/1.2.0/repos/oss/ia32/packages/ \
    --arch i686 kernel.spec \
    --dist  /usr/lib/build/configs/meego-1.2.conf 

binary RPM package can be found in /var/tmp/build-root/home/abuild/rpmbuild/RPMS/.

Trouble shooting

rpm verify failed

If you encounter "rpm verify failed" issue while executing build. You need to download the meego-release pacakge from repo, and import the gpg key in meego-release package.

For example:

   wget http://repo.meego.com/MeeGo/releases/1.2.0/repos/oss/ia32/packages/noarch/meego-release-1.2.0-2.1.noarch.rpm
   rpm2cpio meego-release-1.2.0-2.1.noarch.rpm | cpio -idmv
   rpm --import ./etc/pki/rpm-gpg/RPM-GPG-KEY-meego02

build kernel on 64 bit system

You may encounter some issue while your host system is 64 bit, in this case, you'd better go into the chroot env, and build it manually. for example: you may met the follow error while building kernel

 -----------------------------------------------------------------
 ----- building kernel.spec (user abuild)
 -----------------------------------------------------------------
 -----------------------------------------------------------------
 + exec rpmbuild -ba --define '_srcdefattr (-,root,root)' /home/abuild/rpmbuild/SOURCES/kernel.spec
 error: Architecture is not included: x86_64

You can follow the steps to solve this :

 [root@xq-desktop development]# chroot /var/tmp/mybuildroot/
 bash-3.2# su abuild
 bash-3.2$ exec rpmbuild -ba --define '_srcdefattr (-,root,root)' /home/abuild/rpmbuild/SOURCES/kernel.spec --target=i686

You may also meet compiling error as follows:

 sorry, unimplemented: 64-bit mode not compiled in

To solve this issue, you still need to go into chroot, and exclude -m64 options in CFLAGS CXXFLAGS and CPPFLAGS.