BuildRoot 2015.08.1 + Linux 4.2.2 on Arietta G25

BuildRoot is a set of makefiles and patches that makes it easy to generate a complete Embedded Linux System. It can generate any or all of a cross-compilation toolchain, a root filesystem, a kernel image and a bootloader image

This article explains how to create a bootable microSD for Arietta G25 SoM using the latest BuildRoot version and the latest stable Kernel version available now (Oct 2, 2015).

Building procedure

Download BuildRoot version 2015.08.1 from its repository:

Download buildroot-2015.08.1.tar.bz2

Decompress the .bz2 file in your home directory and move inside the new directory:

~$ tar xjvf buildroot-2015.08.1.tar.bz2
~$ cd buildroot-2015.08.1
~/buildroot-2015.08.1$ 

Download our patch file to add the file requested by Arietta G25:

Download acme.patch

and apply it by typing:

~/buildroot-2015.08.1$ patch -p1 < acme.patch

Select the Arietta G25 defconfig:

~/buildroot-2015.08.1$ make arietta_defconfig

If you're running an Ubuntu distribution at 64 bit, install the libc6-i386 (sudo apt-get install libc6-i386)

Install liblz4-tool (sudo apt-get install liblz4-tool) used to generate the Linux Kernel zImage

Save and exit from the configuration menu and launch the BuildRoot compilation.

This operation will take about 1 hour to download and compile any source of any part of your Linux distribution.

~/buildroot-2015.08.1$ make
...

If everything goes well you will obtain these binary files in output/images directory:

  • The Linux Kernel image: zImage
  • The device tree blob file: acme-arietta.dtb
  • The whole root file system contents: rootfs.tar

Insert a microSD formated in this way using gparted:

  • a first fat16 or fat32 partition (>6 MB) labeled boot
  • a second ext4 partition (>32 MB) labeled rootfs

Copy the files generated renaming some of them in this way:

cp output/images/at91-ariettag25.dtb /media/$USER/boot/acme-arietta.dtb
cp output/images/zImage /media/$USER/boot
sudo tar xvf output/images/rootfs.tar -C /media/$USER/rootfs

Unmount the microSD and boot on your Aria. It will take about 2 minutes the first time to calculate the openssh keys. The next boots it will take just 5 secs.

At login:

  • login: root
  • password: acmesystems

Changing Linux Kernel configuration

If you want to change something of the basic BuildRoot configuration (like adding packages) type:

~/buildroot-2015.08.1$ make menuconfig

If you want to change something in the Linux Kernel configuration (like adding some drivers) type:

~/buildroot-2015.08.1$ make linux-menuconfig

Related links