Mu-arm

ARM Microcontroller

Build the kernel

To get running the kernel, we need to setup the environment with the proper toolchain so we can start to cross-compile the kernel.

GNU ARM Toolchain

• Download arm-none-linux-gnueabi from sourcery.mentor.com or the manufacturer website
• Decompress the tarball and place in `~/CROSS_COMPILER`
• Add the path to your environment by editing `~/.bash_profile` and adding

 PATH=$PATH:$HOME/bin:~/CROSS_COMPILER/arm/4.4.3/bin
 

Build the kernel

• Download the kernel from kernel.org
• Create a working directory and decompress the kernel inside there

 # mkdir kernel
 # cd kernel
 # wget http://mirrors.kernel.org/...linux-2.6.36...
 # tar zxvf linux-2.6.36*tgz
 # mkdir kernel-bin
 # cd linux-2.6.36
 

• Generate `.config`

 CROSS_COMPILE=arm-none-linux-gnueabi- ARCH=arm make O=../kernel-bin/ mini2440_defconfig
 

• Modify the kernel

 # cd ../kernel-bin
 # make ARCH=arm menuconfig
 # cd ../mini2440
 

• Cross compile the kernel and modules

 CROSS_COMPILE=arm-none-linux-gnueabi- ARCH=arm make O=../kernel-bin/
 

• If using uboot, then generate uImage

 # ../uboot/tools/mkimage -A arm -O linux -T kernel -C none -a 0x30008000 -e 0x30008000 -d ../kernel-bin/arch/arm/boot/zImage ../uImage
 

=== Kernel Modules ===

• Build the modules that are going to be placed into the filesystem

 CROSS_COMPILE=arm-none-linux-gnueabi- ARCH=arm make O=../kernel-bin/ modules
 CROSS_COMPILE=arm-none-linux-gnueabi- ARCH=arm make O=../kernel-bin/ INSTALL_MOD_PATH=.. modules_install
 

• Mount the FS image and copy the files inside the root folder

 # cp ../lib/modules/2.6.36/ /mnt/mini2440/rootfs/lib/modules/ -r
 

=== uboot ===

• Get the sources from git repository

 # mkdir uboot
 # cd uboot
 # git clone git://repo.or.cz/u-boot-openmoko/mini2440.git
 

• Prepare and build uboot

 # cd mini2440
 # make mini2440_config
 # make all