New GPU driver

[rohezal]

This may be very interessting for Nintendo 64 Emulation, since you can access the GPU directly. This would avoid to use expensive shaders to simulate N64 GPU stuff.


From Open Moko Mailing list:

FSF has set up a new PowerVR SGX reverse engineering project
proposed by Luke K.C. Leighton.


Since we have such a GPU in our GTA04 SoC (DM3730), I think there


may be some interest here on this list to support this effort.


The goal is to write free and open replacement drivers and firmware


and maybe do fancy stuff with the GPU shader cores (signal and


image processing).


The mailing list is here:


https://lists.nongnu.org/mailman/listinfo/powervr-devel


and the project home page is here:


https://savannah.nongnu.org/projects/powervr/


A wiki is being set up by someone soon...


There isn't much more information since the project was just set up.


IMHO a good starting point with a general architectural description


of the PowerVR SGX system can be found in the DM3730 TRM [1].


Someone has found out a little [2] about the USSE instruction set,


which appears to include e.g. Multiply+Add, Fraction, Square Root,


Log, Min/Max, And, Or, Xor. I think this makes it quite useful for signal


processing. But that appears to be all what is known currently.


I encourage to contribute to this project since it will make the GTA04


and OpenPhoenux even more useful for the FLOSS communities.


Nikolaus


[1] http://www.ti.com/lit/ug/sprugn4p/sprugn4p.pdf Chapter 8


[2] http://lkcl.net/powervr/sgx/

 

[Askarus]

This may be very interessting for Nintendo 64 Emulation, since you can access the GPU directly. This would avoid to use expensive shaders to simulate N64 GPU stuff.

Did I read N64?


Hope comes back

 

[Letalis Sonus]

You know, their last achievement was that they drew a triangle... It will take years until this thing is somewhat usable.

 

[Caine]

Indeed, by the time they finish this nobody will be using that chip anymore. Nevertheless, nice to see a project for it.

 

[Trip]

You know, their last achievement was that they drew a triangle... It will take years until this thing is somewhat usable.

You never know with things like this. Some times all it takes is to get past that first hurdle and everything else just slides into place.


I hold out hope

 

[notaz]

SGX reverse engineering is FSF's "high priority" project since early 2011 and absolutely nothing has come out of it as far as I know.

You know, their last achievement was that they drew a triangle... It will take years until this thing is somewhat usable.

That was for a totally different chip (forget what it was now), AFAIK there is no working code whatsoever for SGX.

 

[Letalis Sonus]

That was for a totally different chip (forget what it was now), AFAIK there is no working code whatsoever for SGX.

Ah right, that was the Mali driver...


Looks even worse then.

 

[laurencevde]

And one of TI's GPU-driver-developers is reverse-engineering qualcomm's chips in his free time, because he wants open-source drivers, and he can do those without breaking NDA's...

 

[fusion_power]

Wouldn't it be much more efficient if the Chip Companies just make propper drivers instead that a community has to do reverse engineering to improve original Chipset drivers and firmware stuff?


I really wonder sometimes how TI or SGX manage to sell their Processors when it is so hard to use all of their features.

 

[ShleeDragon]

You understand the driver doesn't actually exist right? They're currently a pipe dream? with a little bit of money behind it.


I doubt we'll see much of anything.

 

[Linux-SWAT]

A recent slashdot article :


http://hardware.slashdot.org/story/12/06/17/1551212/powervr-to-make-mobile-graphics-gpu-compute-a-three-way-race-again

 

[Stephane Hockenhull]

Wouldn't it be much more efficient if the Chip Companies just make propper drivers instead that a community has to do reverse engineering to improve original Chipset drivers and firmware stuff?


I really wonder sometimes how TI or SGX manage to sell their Processors when it is so hard to use all of their features.

PowerVR sell well because they've got the fastest GPU when paired with ultra-slow mobile RAM.


and their GPU is also quite power efficient, it doesn't eat up batteries as much as other solutions.


when RAM is slow as snail, the PVR with its tile-based rendering still gets decent performance.


its one of the best mobile GPU if not the best.


they're not harder to use than other OpenGL ES GPUs.


and they can't open up their chip documentation because of patent licensing and NDA issues.