BEC OpenEmbedded build template

Build system based on oe-core, OpenEmbedded, and Angstrom.

Example

This following is example of building and installing a linux system from scratch on the BeagleBoard.

git clone git://github.com/cbrake/oe-build.git
cd oe-build
. envsetup.sh
oe_setup
bitbake systemd-image
[insert SD card]
lsblk (note sd card device)
oe_partition_sd /dev/sdX
oe_install_sd_boot (install MLO, u-boot, kernel)
oe_install_sd_rootfs_systemd_image
[Install SD card in beagleboard and enjoy your new image]
oe_console (fire up a serial console for the machine)

Motivation

This build template is designed to be used for production build systems (used to build product software), and thus has the following goals:

simplicity: uses well understood things like bash and git submodules.
robustness: Git submodules are a robust solution for production environments, and error handling good. Git submodules are also very good at making sure you are building exactly what was checked in, because it locks every submodule down to a specific version, which is generally what you want for a production build system, where the build must be absolutely repeatable.
generate a modern Linux root filesystem.
uses systemd
track development of layers (we want the latest bits)
support a range of common development platforms and SOCs

Tested Machines

beagleboard
BSP components from meta-ti
3.2 kernel
beaglebone
BSP components from meta-beagleboard
3.8 kernel
overo (Gumstix)
BSP components from meta-gumstix-community
3.5 kernel
wandboard-dual
in progress
BSP components from meta-fsl-arm and meta-fsl-arm-extra
must set ACCEPT_FSL_EULA = "1" in local.conf or locallocal.conf

Using

envsetup.sh

This is where all the magic happens. In general, this build system must be run in a bash shell. To set up the environment, source the following file:

. envsetup.sh

This file will create a bunch of functions in the environment prefixed with oe_ that can be executed. Type oe_ to see them.

directories and key files

build: temporary directory where build actually takes place
conf: configuration files for the build
sources: various sources used for the build. The entries in this directory are git submodules.
downloads: contains files that are downloaded by various recipes during builds.
tools: utility scripts
localconfig.sh: file created by envsetup.sh that contains directory specific variables based on the build system location.
local.sh: can be used to customize MACHINE, and other variables

building for another machine

export MACHINE=[my machine]
bitbake [recipe name]

adding a new layer

git submodule add sources/meta-mylayer
add layer to conf/bblayers.conf

customizing settings

conf/local.conf contains settings that are commonly modified such as parallel build options.

starting a local feed server

Sometimes you want to install packages you build on the target system without building and re-installing the entire rootfs. This can be done using a feed server.

Workstation: oe_feed_server (this starts a feed server on port 4000)
Target: modify /etc/opkg to http://[your workstation IP]:4000
Target: opkg update
Target: opkg install [package]

This advantage of a feed server versus scp'ing opkg files to the target and installing manually is that dependencies will automatically get installed. This mechanism is very useful for packages that are only needed occasionally during development (gdb, screen, strace, iperf, etc).

updating the submodules to the latest

Assuming you have a recent version of git, you can make use of the branch values specified in .gitmodules to update each submodule branch to the HEAD of the specified branch:

git submodule update --remote

License

This build system is licensed under the MIT license which is the same license as oe-core, etc. See COPYING.MIT

Contributions are welcome: please email cbrake@bec-systems.com

xlcwu / oe-build