Buildroot for the BeagleBone

This README contains basic instructions for creating a system image for the BeagleBone using Buildroot. The image created is minimal, boots quickly, is fairly small, but doesn't do much. Packages can easily be added using Buildroot's "make menuconfig" configuration editor.

Project status

March 26, 2012 - I'm in the process of sending the patches to add BeagleBone support to buildroot upstream. As a result, I've been negligent in keeping this project up-to-date. It works fine, but does not have the Linux 3.2 kernel that many people are using now on the BeagleBone. The patches that I am sending upstream do support Linux 3.2.

If you would like a version of buildroot that supports Linux 3.2, please see bbone-erlang-buildroot. It is a fairly bare-bones image with the exception that the Erlang runtime is turned on by default. Just turn it off in "make menuconfig".

I will be posting to the beagleboard email list as soon as the upstream buildroot project fully supports the BeagleBone.

Preparing your system

Buildroot requires several packages to be installed on the system before it can work. On Ubuntu, the following apt-get line is sufficient:

sudo apt-get install git-core bison flex g++ gettext texinfo libncurses5-dev

Building

Select the Buildroot configuration. Two BeagleBone configurations are available depending on the desired C library. The uclibc system is self-contained and builds host-side tools such as the cross-compiler. The glibc system requires the TI AM335x SDK to be installed and is a work in progress.

To select the uclibc system, run:

make beaglebone_uclibc_defconfig

To build everything, run:

make

The initial build takes a while since many packages need to be downloaded and built. The downloads are cached in the dl directory. Subsequent builds are faster.

The build output is stored in the output/images directory.

Creating a BeagleBone MicroSD card

The MicroSD card that comes with the BeagleBone is partitioned properly for the BuildRoot image. To format a new MicroSD card, the following will work:

sudo sfdisk -H 255 -S 63 /dev/XXXXXX << EOF
0,9,c,*
,124
EOF

sudo mkfs.vfat /dev/XXXXXX -n boot

Then copy the built images to the SD Card:

# Copy the bootloaders and the Linux kernel
cp MLO u-boot.img uImage /media/boot

# Copy the root file system (replace sdd2 with the second partition of right
# device)
sudo dd if=rootfs.ext2 of=/dev/sdd2 bs=128k

Notes

Bring up the ethernet interface:

# udhcp