Building a Custom Linux Kernel Using Angstrom

Compile the Linux kernel and root file system using the Arria 10 SoC device Ångström recipes

Prerequisites

To build Linux on Ubuntu 12.04 LTS using Ångström, there are certain packages that must be preinstalled.

To install these packages, type the following commands:

sudo apt-get install gawk wget git-core diffstat unzip texinfo gcc-multilib \
build-essential chrpath libsdl1.2-dev xterm

You also need to set the default shell to bash. Select No when you are prompted to use dash as the system shell:

sudo dpkg-reconfigure dash

Building Linux

1. Clone the Angstrom git trees:

mkdir <PATH_TO_ANGSTROM_DIR>
cd <PATH_TO_ANGSTROM_DIR>
git clone git://github.com/altera-opensource/angstrom-socfpga.git
cd angstrom-socfpga
git checkout angstrom-v2014.12-socfpga

2. Update the layer configuration to remove an unused layer that was taken offline by the community

Edit file conf/bblayers.conf to remove the following line:

${TOPDIR}/sources/meta-gumstix-community \

Edit thefile sources/layers.txt to remove the following line:

meta-gumstix-community,https://gitorious.org/schnitzeltony-oe-meta/meta-gumstix-community.git,\
master,d2017d3efe8d63940ec6aa33cd6e102e2d39dfc5

3. Retrieve the required layers

MACHINE=arria10swvp ./oebb.sh config arria10swvp

4. Build kernel and rootfilesystem by running the following commands:

source environment-angstrom-v2014.12
export KERNEL_PROVIDER="linux-altera-ltsi"
export KERNEL_TAG="51a839398fdcdda7b283b7ac27425011c436525d"
export BB_ENV_EXTRAWHITE="${BB_ENV_EXTRAWHITE} KERNEL_PROVIDER KERNEL_TAG" 
MACHINE=arria10swvp bitbake virtual/kernel console-image virtual/bootloader

This will create the following relevant files in /angstrom_socfpga/deploy/glibc/images/arria10swvp/:

• zImage - Linux kernel image
• socfpga_arria10_swvp.dtb - Linux device tree
• console-image-arria10swvp.tar.xz - root filesystem

Update Linux Image

This section presents how to update the Virtual Platform image to include the newly built Linux kernel and device tree.

1. Download the required Linaro toolchain and setup the environment accordingly:

mkdir <PATH_TO_TOOLCHAIN_INSTALL>
cd <PATH_TO_TOOLCHAIN_INSTALL>
sudo apt-get install ia32-libs
wget https://releases.linaro.org/13.12/components/toolchain/binaries/\
gcc-linaro-arm-linux-gnueabihf-4.8-2013.12_linux.tar.bz2
tar xjvf gcc-linaro-arm-linux-gnueabihf-4.8-2013.12_linux.tar.bz2
export PATH=$PWD/gcc-linaro-arm-linux-gnueabihf-4.8-2013.12_linux/bin:$PATH
export CROSS_COMPILE=arm-linux-gnueabihf-

2. Run the build script:

cd <PATH_TO_VP_INSTALL>/Software/arria10/linux/buildsocvpelf
./build.sh <PATH_TO_ANGSTROM_DIR>/angstrom_socfpga/deploy/glibc/images/\
arria10swvp/zImage \
<PATH_TO_ANGSTROM_DIR>/angstrom-socfpga/deploy/glibc/images/arria10swvp/\
socfpga_arria10_swvp.dtb \
linux-system-sd.elf \
arm-linux-gnueabihf-

This script creates the linux-system-sd.elf file. You can replace a similar file contained in the Rocketboards Linux binary package in one of two ways:

• Move the new file to <PATH_TO_VP_INSTALL>/Software/arria10/linux.
• Update <PATH_TO_VP_INSTALL>/parameters_Arria10.txt to point to the new file.

Once the build.sh script has completed, you can run the virtual platform as usual.

Update SD Card

1. To create a new SD card image file that can be used as the SD card image, run the following:

cd /Software/arria10/linux/buildsocvpsd
./buildsd.sh <PATH_TO_ANGSTROM> \
arria10swvp arria10_swvp

This script creates the sd-angstrom-v2014.12-arria10swvp.img file. This file must be writable by the user who runs the virtual platform. To give the user write permissions type:

sudo chown $USER:$USER sd-angstrom-v2014.12-arria10swvp.img

Move this image file to the Linux binary directory in one of two ways:

• Move the new file to <PATH_TO_VP_INSTALL>/Software/arria10/linux.
• Update <PATH_TO_VP_INSTALL>/parameters_Arria10.txt to point to this file.

Run the Updated System

Run the Virtual Platform as usual:

cd <PATH_TO_VP_INSTALL>
./run.exe