Compiling the Gumstix kernel

This is a walk-through for compiling the Gumstix 2.6.39 power management kernel (uImage), using the Emdebian/Debian tools (instead of using OpenEmbedded/Bitbake). The steps should be similar for newer kernels.

2014-12-15 Note: Use the updated kernel source at https://github.com/gumstix/linux

I created this walk-through on Ubuntu 12.04; any recent Debian or derivative should suffice.

1. Prepare your system (gcc-4.3 cross-toolchain from Emdebian, for more details, see http://wiki.debian.org/EmdebianToolchain#Get_the_binaries):

   sudo bash
   apt-get install git u-boot-tools emdebian-archive-keyring
   echo "deb http://www.emdebian.org/debian squeeze main" >> /etc/apt/sources.list
   apt-get update
   apt-get install gcc-4.3-arm-linux-gnueabi
   exit
   

2. Use git to fetch the kernel source:

   git clone git://www2.sakoman.com/git/linux-omap-2.6.git
   cd linux-omap-2.6
   git checkout --track -b omap-2.6-pm origin/omap-2.6.39-pm
   

   (Here's where you could choose a newer kernel version by choosing a different git branch).

3. Set your environmental variables to use the correct cross-toolchain (download: kernel-dev-deb.env)

   source kernel-dev-deb.env
   

4. The kernel configuration used here (config-2.6.39) is a slightly modified version of Steve Sakoman's PM configuration from the Open Embedded repository. See his blog post as well.

5. Copy the downloaded config to linux-omap-2.6.git/.config and (if desired)

   make menuconfig
   

   to modify it.

6. When you have a .config that makes you happy, build the image uImage and modules

   make include/linux/version.h
   make uImage
   make modules
   

7. To install them:

   make modules_install INSTALL_MOD_PATH=/media/rootfs
   cp arch/arm/boot/uImage /media/boot
   

   Change /media/rootfs and /media/boot to correspond to your root filesystem and boot partitions. See InstallOnGumstixOvero for details on partitioning your SD card and creating a filesystem.