N9 Kernel update project

Revision as of 09:39, 24 September 2012

Summary

The N9 kernel currently used with various Mer images is based on old 2.6.32 maemo kernel. This page collects needed info for any developers who might want to help in updating that kernel to latest linux-stable version.

Contact info

• IRC: #mer and #nemomobile @irc.freenode.net
• Mailing list: mer-general@lists.merproject.org
  • CC mer-general if you send patches to upstream lists like linux-omap

Developement

Development git:

https://bitbucket.org/kjokinie/mer-n9-kernel

git clone https://bitbucket.org/kjokinie/mer-n9-kernel.git
git checkout -b mer-latest origin/mer-latest

• mer-latest branch is the latest development branch
• The git tree is public, if you want to contribute patches, contact kjokinie in #mer IRC
• If you make patches it is recommended to send those also to relevant upstream kernel list (most likely linux-omap, as N9 uses omap SoC), this way we don't grow the upstream delta too big.

Build instructions from git

• • Use Mer SDK and SB2 to build.
  • Building (inside Mer-SDK chroot):

sb2 make n9_mer_defconfig
sb2 make -j4 zImage
sb2 make -j4 modules
sb2 make modules_install INSTALL_MOD_PATH=./mods

Deploying to device (kind of "flashing")

• We use helper scripts that prepare the modules etc

./prepare_kernel.sh

• Then use copy script (NOTE: do this outside Mer-SDK chroot)
  • Plug N9 to USB and let it boot so the filesystem gets mounted
  • Then "flash" the kernel (it's just a simple cp actually...)

sudo ./copy_kernel.sh /<path-to>/<mounted>/<N9 filesystem>

Packaging

• OBS used: https://build.pub.meego.com
• OBS API: https://api.pub.meego.com

Packaging development project:

• https://build.pub.meego.com/package/show?package=kernel-adaptation-n950&project=home%3Akjokinie%3Abranches%3AMer%3AMDS%3ACore%3Aarmv7hl

updating pack with git-pkg

• setup git-pkg by cloning it out and copy gp_make_src to PATH
• then do following to update patch set for the OBS pack

osc co <kernel pack>

• do changes in your local mer-n9-linux git mer-latest branch
• if you change base kernel tag version, edit _src to point to right initial commit
• then

#symlink .git from your git tree
ln -s /path-to/mer-n9-linux/.git .git
#run git-pkg script to generate tar and latest patches
gp_make_src

• then copy the "Patches:" lines to your .yaml

specify *.yaml
osc addremove
osc ci -m "latest changes from git..."

TO DO list for kernel update

• Port needed device drivers from 2.6.32 kernel to latest kernel
  • Some hint may come from missing kernel config options found in initial kernel config migration from 2.6.32 to 3.5.3

• Port needed Mer specific patches from old N950 kernel OBS pack
  • Yes, all 100+ patches there should be checked