On 06/10/15 23:56, Grazvydas Ignotas wrote:
Hi,
For the general problem of slow X, we might be able to still use fbturbo on top of omapdrm's fb emulation. That was working at last year's gamescom, on TI's old 3.8 kernel.
Hmm interesting. So fbturbo is an X fbdev driver, with (for this case) NEON optimized operations? I presume none of the HW accelerations included can be used with OMAP?
One issue with fbdev driver, and probably with fbturbo also, is that it's using the fbdev. So it has no understanding of multiple displays, videomodes, etc, etc.
On 10/06/2015 02:23 PM, Tomi Valkeinen wrote:
On 06/10/15 14:18, Michael Mrozek wrote:
That sounds good. notaz might be able to correct me here, but the problem is actually not the closed-source stuff from IMG (like the SGX driver, etc.), but another small binary blob that's used to communicate between X and the SGX driver.
Not X, see below.
There could be other libs that I'm not aware of, but afaik that is the EXA driver. Which is from IMG, and is closed. That driver uses SGX underneath.
It is gbm_pvr.so, which is some weird dependency to mesa. Without it the blobs would not run, and it's tied to ancient mesa from Ubuntu 12.04.
GBM is a buffer allocation library from Mesa. gbm_pvr has the glue between mesa-omapdrm-sgx. It allows opengl to allocate buffers which can be drawn by the SGX and shown on the screen.
There is absolutely no reason to keep this one closed, it's a tiny lib
The reason is IMG =). It's difficult to open source anything related to SGX, as using SGX driver's internal headers makes it impossible to open source it.
If I'm not mistaken, the only public headers from SGX are related to opengl and egl. Any component using any other APIs must be closed source.
with just some glue code (from looking at the symbols), yet it's enough to make distribution maintainer's life miserable.
The EXA driver is separate from the above and it was possible to get 3D going without it (fullscreen without X support, just drawing over what X draws) by doing some nasty hacks, but I already forgot the details.
True, there are many different parts in play.
Tomi