This is a historical description of what is now the kgsl backend

in libdrm freedreno (before the upstream drm/msm driver).  Note

that the kgsl backend requires the "kgsl-drm" shim driver, which

usually is in disrepair (QCOM does not build it for android), and

due to random differences between different downstream android

kernel branches it may or may not work.  So YMMV.

Original README:

----------------

Note that current msm kernel driver is a bit strange.  It provides a

DRM interface for GEM, which is basically sufficient to have DRI2

working.  But it does not provide KMS.  And interface to 2d and 3d

cores is via different other devices (/dev/kgsl-*).  This is not

quite how I'd write a DRM driver, but at this stage it is useful for

xf86-video-freedreno and fdre (and eventual gallium driver) to be

able to work on existing kernel driver from QCOM, to allow to

capture cmdstream dumps from the binary blob drivers without having

to reboot.  So libdrm_freedreno attempts to hide most of the crazy.

The intention is that when there is a proper kernel driver, it will

be mostly just changes in libdrm_freedreno to adapt the gallium

driver and xf86-video-freedreno (ignoring the fbdev->KMS changes).

So don't look at freedreno as an example of how to write a libdrm

module or a DRM driver.. it is just an attempt to paper over a non-

standard kernel driver architecture.