Letux Kernel

Letux Kernel

This is a Subproject of the GTA04 and Openmoko Beagle Hybrid

It provides fully functional Linux kernels for the Openmoko Beagle Hybrid and the GTA04 as well as for devices which are currently being developed (e.g. Neo900, Pyra-Handheld).


latest mainline release candidate: 4.4-rc2 device tree based, multi-platform, not mature enough for daily use
mainline: 4.3.0 device tree based, multi-platform, not mature for daily use
stable: 3.12.37 feature complete (incl. camera), but lacks some power management
stable: 3.12-replicant kernel modified/configured differently to better support Replicant
linux-next: 3.7-neil-plus good power management, lacks some features (e.g. camera)
mainline: gta04-for-next a set of patches on top of linux-next ready for upstreaming

The Mainline-Plus Kernel concept (tracking linus/master = mainline)

See the branches which are based on the mainline linus/master kernel.

Basically there is a "stable" master branch and rolling release candidate branches and feature development ("work in progress") branches. The "latest" branch is a copy of the latest rolling release candidate branch.

Each time Linus publishes a new release candidate (typically once per week on average), we create a new branch and merge. For example, the "master" branch can currently be 3.12.7 but the rolling work is on 3.18-rc3. One week later, we will have 3.18-rc4 and "latest".

As soon as our rolling kernel is feature complete (i.e. nothing important is completely missing) we plan also update the master branch to follow major Linux releases (e.g. 3.19.0).

supported devices (through different device tree files)

  • BeagleBoard C, BeagleBoard XM
  • BeagleBoard (C/XM) with Openmoko Beagle Hybrid expansion board
  • GTA04A3, GTA04A4, GTA04A5 (Letux 2804)
  • GTA04b2 (Letux 3704)
  • GTA04b3 (Letux 7004)
  • planned: GTA04b7 (Neo900)
  • PandaBoard ES
  • OMAP5432EVM
  • OMAP5432EVM + Pyra development boards
  • Letux Cortex 15 (Pyra CPU-Board stand-alone)

For a list of features supported on each device, please see Platforms.


  • follows the latest kernel releases and includes security patches
  • based on the latest www.kernel.org (release candidates)
  • adds the latest Linux features
  • add to support the GTA04 devices what is not (yet) in mainline ("plus")
  • provide drivers for as many hardware features as possible in a clean way
  • can be used in daily life
  • our patches are pushed to go upstream so that the 'plus' part gets smaller and smaller step by step

Features / Maturity

GTA04 devices

basically everything can be supported (and was in the past before we transitioned to the Device Tree). Therefore the most feature-complete version is still the "master" branch (3.12.7).

The branches tracking linus/master currently don't support well (please refer to [issues][Issues]):

  • WiFi power management
  • Sound
  • Microphone Sense
  • Torch/Flash
  • Camera
  • IrDA
  • DSP
  • 3D Accelerator (PVR/SGX)


it works on the BeagleBoard XM with OpenMoko-BeagleHybrid display expander and on a BeagleBoard C w/o.


it appears that everything works (incl. audio)


there is some problem with an EHCI error (for the unconnected HSIC interface) and panel drivers are work in progress. Otherwise it works.


Please download, test and patch the kernel. Please submit patches against the latest version (e.g. 3.18-rc3) and mail them to the gta04-owner mailing list. Thank you!


We actively work on the kernel and upstreaming patches, but this needs some funding for the developers. If you want to donate, you are welcome!


Building the kernel:

git clone http://git.goldelico.com/gta04-kernel.git
cd gta04-kernel
git checkout latest
make ARCH=arm CROSS_COMPILE=arm-none-linux-gnueabi- letux_defconfig uImage LOADADDR=0x80008000 dtbs INSTALL_MOD_PATH=/tmp/kernel-modules-$$ modules modules_install
cp arch/arm/boot/uImage modules arch/arm/boot/dts/omap*.dtb /mount/sdcard/boot/

(you can also use git://git.goldelico.com/gta04-kernel.git but this is a little less reliable on weak connections).

Please refer to the GTA04 Rootfs for installation instructions of a complete distribution (bootloader, kernel, rootfs, LXDE GUI).

Controlling Hardware Features from User Space

You want to control the hardware features from user space. How this is done can be seen in the Documentation and Devices-Overview .

Powered by InDefero,
a Céondo Ltd initiative.