Monthly Archives: August 2014

Building the Arietta G25 Kernel

I’m using the Arietta G25 for a project of mine. Earlier I described how to build a bootloader for the 256MB version of the board.

Today I’m going to describe how to build the kernel for the Arietta G25. I needed ADC support as well as modules for some USB to ethernet adaptors that weren’t included in the kernel image ACME Systems provides.

First off you will need to install the toolchain to build armel binaries. ACME Systems has a page describing how to install the ARM9 toolchain. Here’s the short summary:

$ sudo apt-get install emdebian-archive-keyring libc6-armel-cross libc6-dev-armel-cross binutils-arm-linux-gnueabi gcc-arm-linux-gnueabi g++-arm-linux-gnueabi u-boot-tools libncurses5-dev

Once you have the environment setup it’s time to checkout the kernel and build. This is the Jenkins script I use to build the Arietta G25 kernel:

if [ ! -d "linux-3.14.7" ]; then
wget -O linux-3.14.7.tar.xz
tar xvfJ linux-3.14.7.tar.xz
cd linux-3.14.7
wget -O acme.patch
patch -p1 < acme.patch

wget -O .config
wget -O arietta_256m_ikconfig.patch
patch -p1 < arietta_256m_ikconfig.patch
cd linux-3.14.7
make ARCH=arm clean
CPUS=$(cat /proc/cpuinfo | grep -c "processor")

wget -O arch/arm/boot/dts/acme-arietta.dtb
make -j$CPUS ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- zImage
make modules -j$CPUS ARCH=arm CROSS_COMPILE=arm-linux-gnueabi-
make modules_install INSTALL_MOD_PATH=./modules ARCH=arm
mkdir -p modules/boot
cp arch/arm/boot/zImage modules/boot/
rm linux-3.14.7-arietta.tar.bz2
tar -C modules -cjvf linux-3.14.7-arietta.tar.bz2 lib/ boot/

The above commands are available in a bash/Jenkins script at the bottom of this post.

Installation is fairly simple, you need to mount the sdcard /boot and / partitions on your computer and then run:

tar -C /path/to/sdcard -jxvf linux-3.14.7-arietta.tar.bz2

My kernel configuration includes the Atmel ADC driver as a module (at91_adc) so you can unload/reload it (possibly to save power). It also includes the dm9601 and sr9700 modules for the Davicom DM96xx USB 2.0 10/100M Ethernet Adaptor, which is an inexpensive USB to ethernet adaptor available online (such as this one).

If you want to generate your own dtb (for instance enable PWM instead of the ADC) you can do that at this ACME Systems page.

Build script:
Kernel and modules: linux-3.14.7-arietta.tar.bz2
Kernel Config: linux-at91-3.14.7.config

Building the Banana Pi LeMaker Kernel

I recently bought a Banana Pi because I wanted something more powerful than a Raspberry Pi (and because I had store credit to use up).

I wanted to run Debian on it, but not the Raspbian distribution provided by Lemaker because I find it’s too resource heavy for what I will be using my Banana Pi for. I followed Christian Bock’s excellent blog post on how to build a Debian rootfs for the Banana Pi.

More pre-built SD card images are coming out for the Banana Pi, but I wanted to use a spare 1GB microSD card and no one provides images that small, so I went and built my own.

As Christian noted in his blog post, the sunxi kernel sources do not work well on the Banana Pi as they contain a broken sunxi ethernet driver. The NIC is unstable when running at gigabit speeds (my testing showed approximately 60% packet loss). A definite deal-breaker if you need reliable network access. LeMaker was a bit slow in releasing their kernel source, but after users complained it was released on github.

Prerequisites for building the kernel are outlined in LeMaker’s wiki page. Basically you need the following packages:

build-essential u-boot-tools uboot-mkimage binutils-arm-linux-gnueabihf gcc-4.7-arm-linux-gnueabihf-base g++-4.7-arm-linux-gnueabihf gcc-arm-linux-gnueabihf cpp-arm-linux-gnueabihf libusb-1.0-0 libusb-1.0-0-dev git wget fakeroot kernel-package zlib1g-dev libncurses5-dev

This is the Jenkins script I use to build the LeMaker kernel for the Banana Pi:

if [ ! -d "linux-bananapi" ]; then
git clone -b bananapi-3.4
cd linux-bananapi
git pull
wget -O .config
make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- clean
make -j4 ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- uImage modules
make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- INSTALL_MOD_PATH=output modules_install
mkdir -p output/boot/
cp arch/arm/boot/uImage output/boot/
tar -C output -cjvf ../linux-bananapi-3.4.90.tar.bz2 boot/ lib/

I’ve included the above commands in a script at the end of this post. I’ve added additional comments explaining the what and why for people who don’t arbitrarily trust strangers on the internet.

Installation is fairly simple, you need to mount the sdcard /boot and / partitions on your computer and then run:

tar -C /path/to/sdcard -jxvf linux-bananapi-3.4.90.tar.bz2

This will extract /boot/uImage and the kernel modules to /lib/modules/3.4.90-00261-gb3b7287

My kernel configuration includes the sunxi ethernet driver as a module (sunxi_gmac) so that you can unload/reload it if necessary. This means you need to use both the uImage and the modules provided or you will not have network connectivity.

Build script: bash/Jenkins build script
Kernel and modules: linux-bananapi-3.4.90.tar.bz2
Kernel Config: linux-bananapi-3.4.90.config