Recompile kernel

Revision as of 13:59, 29 June 2011

Recompiling the MeeGo Kernel

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.

Environment setup

build kernel in chroot

• install 'build'
  • You can get build binary package from http://repo.meego.com/MeeGo/tools/repos/ per your Linux distribution, if your Linux distribution isn't there, you can get build source package from http://www.gitorious.org/opensuse/build to build it yourself manually.
• configure 'proxy'
  • If your network needs proxy, please export proxy environment variables, for example:

export http_proxy=http://proxy.yourcompany.com:8080/
export no_proxy=localhost,127.0.0.0/8,.yourcompany.com, 172.16.0.0/16 

• • If you used to run “sudo build …” and your network needs proxy, please ensure sudo to inherit proxy environment variables, you can do this by adding the below line to /etc/sudoers

Defaults    env_keep += "http_proxy no_proxy HTTP_PROXY NO_PROXY"

build kernel in MeeGo

If your host system is MeeGo, you should install some additional packages, including build, perl-XML-Parser

build kernel in VM

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/1.1/core/repos/source/kernel-2.6.35.3-10.3.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;

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-2.6.35.3-10.3.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 XXX.spec

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 MeeGo system

If your host system is MeeGo, you should install some additional packages, including build, perl-XML-Parser.

build kernel on 64 bit system

You may occur some issue while your host system is 64 bit, once you have encountered issue, you'd better chroot to 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 should 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.