1This is a historical description of what is now the kgsl backend 2in libdrm freedreno (before the upstream drm/msm driver). Note 3that the kgsl backend requires the "kgsl-drm" shim driver, which 4usually is in disrepair (QCOM does not build it for android), and 5due to random differences between different downstream android 6kernel branches it may or may not work. So YMMV. 7 8Original README: 9---------------- 10 11Note that current msm kernel driver is a bit strange. It provides a 12DRM interface for GEM, which is basically sufficient to have DRI2 13working. But it does not provide KMS. And interface to 2d and 3d 14cores is via different other devices (/dev/kgsl-*). This is not 15quite how I'd write a DRM driver, but at this stage it is useful for 16xf86-video-freedreno and fdre (and eventual gallium driver) to be 17able to work on existing kernel driver from QCOM, to allow to 18capture cmdstream dumps from the binary blob drivers without having 19to reboot. So libdrm_freedreno attempts to hide most of the crazy. 20The intention is that when there is a proper kernel driver, it will 21be mostly just changes in libdrm_freedreno to adapt the gallium 22driver and xf86-video-freedreno (ignoring the fbdev->KMS changes). 23 24So don't look at freedreno as an example of how to write a libdrm 25module or a DRM driver.. it is just an attempt to paper over a non- 26standard kernel driver architecture. 27