It uses the Linux KConfig configuration system, allowing easy selection of root fs contents. The Makefile will include the ".config" file generated by KConfig, and the contents of this file will determine what should be built, and which version should be used.

Buildroot

The Buildroot for AT91 can build

• Cross-compiler
• AT91Bootstrap
• U-Boot
• U-Boot configuration scripts
• Linux
• Root file systems of different types

Downloading Buildroot

The script at the end will download the original Buildroot for AT91.

Buildroot Documentation

Configuring the Buildroot Download location.

sudo mkdir -p /usr/local/install/downloads

Then you should add the following line to your ~/.bashrc

export BUILDROOT_DL_DIR=/usr/local/install/downloads

Configuring Buildroot

$ make menuconfig

Making a custom project

Deprecated AT91 Buildroot

$ svn co svn://uclibc.org/trunk/buildroot

Once you have downloaded, you could try out building for the AT91SAM9260? by running the following commands.

$ make menuconfig $ make at91sam9260dfc_defconfig $ make > at91sam9260dfc.log 2>&1

The first command will start the buildroot configuration menu. It is neccessary to run this due to a minor bug in the Makefile, and you can exit this immediately. The only effect is that it will create a valid ".config" file.

The second command will copy a valid buildroot configuration to the ".config" file.

The third command will build everything.

Buildroot can build * Cross-compiler * Bootstrap * U-Boot * Linux * Root file system

It will take 3-4 hours to run on a P4-3.6 GHz.

If you want to create your own board support package, you start by using one of the basic boards. (Look in "target/device/Atmel/*" for "<*>_defconfig" files)

make at91sam9260dfc_defconfig will configure to use the AT91SAM9260? running from the dataflashcard.

Once the config file is OK, you could type:

$ make configured

This will unpack linux and busybox in the "project_build_dir/" directory and uclibc in the "toolchain/uClibc-" directory. You can by entering this directory and typing the appropriate command reconfigure the package.

I.E: In linux the $ make ARCH=arm xconfig command would do the trick.

When you do $ make menuconfig from the top directory of buildroot, you can define a PROJECT name somewhere, and this will be used for many things.

By doing $ make saveconfig

you will save the configuration of busybox, uclibc and linux in the "local/" directory, and this can be retrieved by

$ make B= getconfig

#!/bin/bash
# All previous patches was applied to vanilla buildroot from May 31st.
# Most, if not all suggestions from other people have been applied, - thanks!
# Also updated the u-boot-1.2.0-atmel.tar.bz2 so you need to delete this
# from your download directory (default /usr/local/install/downloads)
# --------------
# Updated 2007-06-07: FIx mkimage path problem
# /Ulf

TOPDIR=`pwd`


BUILDROOT=buildroot-atmel
BUILDROOT_VER=2007-06-07

IPADDR=10.175.196.19
SERVERIP=10.175.196.220
GATEWAYIP=10.175.196.1

BUILDROOT_SOURCE=${BUILDROOT}-${BUILDROOT_VER}.cpio.bz2
BUILDROOT_SITE=ftp://at91dist:distrib@81.80.104.162/AT91_Third_Party_Design_Flow/Linux_Host/Source
DL_DIR=${TOPDIR}/Source
UNZIP=bzcat

function prepare_directories()
{
    mkdir -p /tftpboot
    mkdir -p /usr/local/arm
    mkdir -p /usr/local/install/downloads
}

function get_buildroot()
{
    if ! [ -d ${BUILDROOT} ] ; then
        mkdir -p ${DL_DIR}
        wget -P ${DL_DIR} ${BUILDROOT_SITE}/${BUILDROOT_SOURCE}
        ${UNZIP} ${DL_DIR}/${BUILDROOT_SOURCE} | cpio -idv
    fi
}



function set_ipaddresses()
{
    cd ${BUILDROOT}
    echo "configuring ip addresses"
    ./netcfg.sh ${IPADDR} ${SERVERIP} ${GATEWAYIP}
    cd ${TOPDIR}
}


function make_board()
{
    cd ${BUILDROOT}
    echo "building board $1"
    make B=$1 board
    make $2
    make saveconfig
    cd ${TOPDIR}
}

function make_all_boards()
{
    make_board at91rm9200df $1
    make_board at91sam9260dfc $1
    make_board at91sam9261ek $1
    make_board at91sam9263ek $1
}


prepare_directories
get_buildroot
set_ipaddresses
make -C ${BUILDROOT} menuconfig
make_all_boards source
make_all_boards

<-- A short intro taken on the AT91 Forum, can be erased -->

<-- suit it to your needs -->

Buildroot is a preconfigured collection of scripts which downloads, configures, and builds cross compilers, the kernel, busybox, and most of the other stuff needed for a simple, small complete linux distribution and root file system.

It is relatively easy to go from there to adding your own programs and such to it so your entire build process is automated.

(from sam-protal forum)