Post Last Edited by kevindt at 2014-9-25 21:36 |
The GPU in the Cortex A20 chip is a dual core device, but the drivers in the current kernel only support one core. It is possible to upgrade the kernel drivers from the existing release, but there are a significant number of changes required, in multiple files.
Siarhei Siamanshka (ssvb) successfully patched the linux 3.4 kernel for CubieBoard2, which uses the same GPU, and his commits are up on github in his repository. He deserves credit for the great majority of the work here.
I have taken the required commits and converted them to git patches and then cleaned them up to match the current LeMaker source code on github. The two git patches are here:
To patch them into the kernel is simple.
First clone the kernel from github:
then move the patches into the linux-bananapi directory, cd into the same directory, and use git to apply them Copy the Code
- git clone https://github.com/LeMaker/linux-bananapi.git
If you check drivers/gpu/, you should find the new drivers in a new folder (mali_r3p2-01rel2). I have successfully compiled them into the kernel in a Ubuntu cross-compile environment using the modified sunxi_defconfig created by the patches and used the new drivers with mplayer. Copy the Code
- cd linux-bananapi
- git apply ./0001-Imported-the-original-mali-r3p2-01rel2-kernel-module.patch
- git apply ./0002-Sunxi-adaptation-for-mali-r3p2-01rel2-kernel-module.patch
I have also almost finished a script that will automatically create a complete armhf build chain for the bananapi on a clean install of Ubuntu Server 14-04, pull the bananapi sources from github, and then build an image with a base debian system via debootstrap, or add in mplayer and accelerated graphics with these drivers, as well as LXDE GUI desktop. So far it is compiling images well, and mplayer works nicely with H264 HD files, but there are still a few items to tweak.