4700 Kernel Compile Guide

WARNING:

Backup any important data on the board before continuing.

For adding new support to the kernel, or recompiling with more specific options you will need to have an X86 compatible linux host available that can handle the cross compiling. Compiling the kernel on the board is not supported or recommended. Before building the kernel you will need to install a few support libraries on your workstation:

Prerequisites

RHEL/Fedora/CentOS:

yum install ncurses-devel ncurses
yum groupinstall "Development Tools" "Development Libraries"

Ubuntu/Debian:

apt-get install build-essential libncurses5-dev libncursesw5-dev

For other distributions, please refer to their documentation to find equivalent tools.

Set up the Sources and Toolchain

# Download the cross compile toolchain (EABI)from Technologic Systems:
wget ftp://ftp.embeddedTS.com/ts-socket-macrocontrollers/ts-4700-linux/cross-toolchains/arm-2008q3.tar.gz

# Extract to current working directory:
tar xvf arm-2008q3.tar.gz

# Download the Kernel sources
wget ftp://ftp.embeddedTS.com/ts-socket-macrocontrollers/ts-4700-linux/sources/linux-2.6.29-4700_latest.tar.bz2

# Extract the Kernel Sources
tar xvf linux-2.6.29-4700_latest.tar.bz2

cd linux-2.6.29-4700_latest/

Configure the Sources

The kernel sources need a few variables to be exported.

# Set the CROSS_COMPILE variable to the absolute path to the toolchain.  This will be different for your system:
export CROSS_COMPILE=/opt/arm-2008q3/bin/arm-none-linux-gnueabi-

# Normally, ARCH will be set based on your build hosts architecture.
export ARCH=arm

This sets up the default configuration that we ship with for the TS-4700

make ts4700_defconfig

This will bring up a graphical menu where you can edit the configuration to include support for new devices. For Example, to include support for a Prolific USB to serial adapter you would go to 'Device Drivers -> USB Support-> USB Serial Support' and then select 'USB Prolific 2303 Single Port Serial Driver'. Since the kernel only has a limited space, build drivers as modules whenever possible.

make menuconfig

Build the kernel Once you have it configured, start building. This usually takes a few minutes.

make && make modules

The new kernel will be at "arch/arm/boot" in a compressed format called zImage. The uncompressed version is simply called Image. With the default partitioning scheme it is REQUIRED that the kernel be < 2096640 bytes in size. If you need to shorten the size, try including your changes to the kernel as modules instead. Otherwise you will need to resize the kernel partition to account for the size difference.

Install the kernel Now that you have a kernel you can install it as you would our stock. See the #Backup / Restore section for examples on writing this to disk.

Install Modules Script to make directory and install modules

./build-module-bundles.sh

The build-module-bundles.sh script is meant to be run as a user (not root) and will create directories and install modules to them. The directory structure is created at /home/`whoami`/src/ts-4700/dist/<ts4700 kernel release number>/modules-install/. In that directory is initrd-modules/, lib/, and modules-<ts4700 kernel release number>.tgz.

initrd-modules/modules.tar.gz is a tarball that contains a minimal number of modules. This tarball needs to be copied to the initrd partition of the boot media. The boot process of the board will automatically un'tar this and insert any necessary modules.

Now the contents of lib/ can be copied to the root of the TS-4700. It is also possible to copy over modules-<ts4700 kernel release number>.tgz to the TS-4700 and unpack it in the root linux directory. You may want to remove any old modules on the board in /lib/modules/* before copying them to the board to rule out any incompatibilities. Once you boot up to the board, you need to run 'depmod' once to calculate module dependencies. You can then run 'modprobe' with the device drivers you've added. For the Prolific adapter added in the example, this would be:

modprobe pl2303