Compile a uBoot Kernel

From NAS-Central Buffalo - The Linkstation Wiki

This is a tutorial of how to compile a 2.6.21+ uBoot kernel from vanilla gentoo-sources, or from kernel.org sources. While this article was originally written for Gentoo users, it is basically the same for Debian or others distros.

Contents 1 Prepare the build environment and tools 1.1 Gentoo 1.2 Debian 2 Get the sources 2.1 Gentoo 2.2 Debian and other 3 Edit your kernel config 4 Compile your kernel 5 Backup your old kernel and dtb file 6 Compile the dtb file 7 Install the kernel & enable modules 8 Reboot 9 Troubleshooting

Prepare the build environment and tools

Gentoo

Emerge __what tools from portage?__

Debian

apt-get install build-essential uboot-mkimage

Get the sources

Gentoo

Right now (24 Nov 2008) the latest stable version is gentoo-sources-2.6.26-r2.

If you want a newer kernel, add this line to /etc/portage/package.keywords:

sys-kernel/gentoo-sources ~ppc

then download the kernel sources

# emerge -ua gentoo-sources

make a link to the kernel sources

# cd /usr/src
# ln -sfn linux-2.6.26-gentoo-r2 linux

Debian and other

cd /usr/src
wget http://www.kernel.org/pub/linux/kernel/v2.6/linux-2.6.29.1.tar.bz2
tar xjvf linux-2.6.29.1.tar.bz2
ln -sfn linux-2.6.29.1 linux

Edit your kernel config

Clean up before you begin:

# cd /usr/src/linux
# make mrproper

Use the default KuroBox config:

# cp arch/powerpc/configs/linkstation_defconfig .config

Make sure the config is sane:

# make ARCH=powerpc menuconfig

The default config is minimal. You'll have to enable support for any non-standard things you may be using. I use reiserfs and netatalk, so I enabled support for that filesystem and also for appletalk. Also, with recent filesystem developments, you may wish to consider ext4 or others.

For troubleshooting ease, it is a good idea to enable Netconsole kernel access. Enable Device drivers -> Networking device support -> Network console logging support (EXPERIMENTAL)

Compile your kernel

# make uImage && make modules && make modules_install

Sit back and listen to music. Go to the store. Wash the dog.

Backup your old kernel and dtb file

# cp /boot/uImage /boot/uImage.bak
# cp /boot/kuroboxHG.dtb /boot/kuroboxHG.dtb.bak

If you have a LS1/HD, then change your .dtb filename as necessary.

Compile the dtb file

# cd /usr/src/linux/arch/powerpc/boot/dts
# ../dtc -I dts -O dtb -V 16 -o /tmp/kuroboxHG.dtb kuroboxHG.dts
# cp /tmp/kuroboxHG.dtb /boot/kuroboxHG.dtb

Install the kernel & enable modules

# cp /usr/src/linux/arch/powerpc/boot/uImage /boot/uImage
# cd /lib/modules/2.6.2x.x/
# depmod

Reboot

# reboot

With any luck, you'll be booting your new kernel.

Troubleshooting

If something goes wrong, simply boot in EM mode and copy your old kernel back.

# cp /boot/uImage.bak /boot/uImage
# cp /boot/kuroboxHG.dtb.bak /boot/kuroboxHG.dtb
# echo -n "OKOK" > /dev/fl3