Linux and u-boot sources

The Linux kernel sources for the BeagleBoard, BeagleBoard-xM and BeagleBone are maintained on Github.com/BeagleBoard. The U-Boot bootloader sources maintained as part of the U-Boot mainline on git.denx.de.

The production and validation of these kernels is done with the Angstrom Distribution and meta-beagleboard with the OpenEmbedded build system. The sources shared here are done for convenience for those familiar with the git version control system.

Example for installing toolchain

~$ wget http://www.angstrom-distribution.org/toolchains/angstrom-2011.03-x86_64-linux-armv7a-linux-gnueabi-toolchain-qte-4.6.3.tar.bz2
~$ sudo tar -C / -xjf angstrom-2011.03-x86_64-linux-armv7a-linux-gnueabi-toolchain-qte-4.6.3.tar.bz2
~$ export PATH=/usr/local/angstrom/arm/bin:$PATH
 

Example build procedure for BeagleBone MLO and u-boot

~$ git clone git://git.denx.de/u-boot.git && cd u-boot
~/u-boot$ CROSS_COMPILE=arm-angstrom-linux-gnueabi- make am335x_evm
 

Example build procedure for BeagleBone 3.8-rcX kernel

~$ git clone git://github.com/beagleboard/kernel.git && cd kernel
~/kernel$ git checkout 3.8
~/kernel$ ./patch.sh
~/kernel$ cp configs/beaglebone kernel/arch/arm/configs/beaglebone_defconfig
~/kernel$ wget http://arago-project.org/git/projects/?p=am33x-cm3.git\;a=blob_plain\;f=bin/am335x-pm-firmware.bin\;hb=HEAD -O kernel/firmware/am335x-pm-firmware.bin
~/kernel$ cd kernel
~/kernel/kernel$ mkdir rootfs
~/kernel/kernel$ make ARCH=arm CROSS_COMPILE=arm-angstrom-linux-gnueabi- beaglebone_defconfig
~/kernel/kernel$ make ARCH=arm CROSS_COMPILE=arm-angstrom-linux-gnueabi- -j4 uImage dtbs
~/kernel/kernel$ make ARCH=arm CROSS_COMPILE=arm-angstrom-linux-gnueabi- -j4 modules
~/kernel/kernel$ make ARCH=arm CROSS_COMPILE=arm-angstrom-linux-gnueabi- INSTALL_MOD_PATH=$HOME/kernel/kernel/rootfs modules_install
~/kernel/kernel$ make ARCH=arm CROSS_COMPILE=arm-angstrom-linux-gnueabi- uImage-dtb.am335x-bone
~/kernel/kernel$ make ARCH=arm CROSS_COMPILE=arm-angstrom-linux-gnueabi- uImage-dtb.am335x-boneblack
 

Building a kernel module

I applied this patch and that provided the following files:

~/kernel/kernel/hello/hello.c

#include        /* Needed by all modules */
#include        /* Needed for KERN_INFO */
#include          /* Needed for the macros */

static int __init hello_start(void)
{
    printk(KERN_INFO "Loading hello module...\n");
    printk(KERN_INFO "Hello world\n");
    return 0;
}

static void __exit hello_end(void)
{
    printk(KERN_INFO "Goodbye Mr.\n");
}

module_init(hello_start);
module_exit(hello_end);
 

~/kernel/kernel/hello/Makefile

obj-m := hello.o

PWD   := $(shell pwd)
KDIR  := ${PWD}/..

default:
    make -C $(KDIR) SUBDIRS=$(PWD) modules
 

~/kernel/kernel$ cd hello
~/kernel/kernel/hello$ make ARCH=arm CROSS_COMPILE=arm-angstrom-linux-gnueabi- 
 

Last updated by blog.hangerhead.com on Sat Mar 16 2013 12:19:31 GMT-0500 (CDT).