PS3 GPU questions

Technical discussion on the newly released and hard to find PS3.

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jonwil
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Joined: Mon Nov 12, 2007 8:57 pm

PS3 GPU questions

Post by jonwil »

1.How much access does linux/otheros have to the GPU? (i.e. are there any GPU features which is it known not to be possible to access)
2.Has Sony done anything to block access to the GPU (i.e. firmware updates that close access to certain GPU registers etc)
3.Does anyone know if, for licensed games running on the PS3, the graphics libraries are in the BIOS/OS for PS3 games (i.e. in the firmware) or if they are on the game CDs (i.e. linked with the game executable files)
4.Based on the available evidence, does it look like usable 3D (i.e. enough for, say, OpenGL) is going to be possible through otheros/linux?
and 5.Is there enough functionality available to get hardware accelerated 2D working (i.e. enough for fast playback of HD video etc)
IronPeter
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Post by IronPeter »

1.) linux/otheros have pretty full access to the gpu via undocumented functions and hypervisor holes. Via documented functions we have only weak 2D acceleration.

2.) GPU access via holes and undocumented functions is still active in the latest firmware.

3.) Graphics libraries are linked with the game executable files.

4.) There is usable low-level 3D for homebrew. There is no any OpenGL support, but there are rumours about Sony OpenGL driver in the future.

Check this topic http://forums.ps2dev.org/viewtopic.php?t=8364 and this wiki page http://wiki.ps2dev.org/ps3:rsx
unsolo
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Location: OSLO Norway

Post by unsolo »

Ironpeter
I recon you will agree with me that its likely a spu accellerated MESA (which is under development to my knowledge) can provide a openGL interface on the ps3 no matter what happens.

Furthermore my 2d proof of concept Xv driver in spu-medialib works with video upscaled to 1920x1080

As i am also working on general EXA accelleration on spu i would say that it will defenitly become better to use ps3 desktop.

Even if the GPU is fully blocked.
Don't do it alone.
jonwil
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Joined: Mon Nov 12, 2007 8:57 pm

Post by jonwil »

Is there any reason why an OpenGL driver could not be written even without Sony? Although I guess if it was that simple, the Nouveau people would have done it for PC NV GPUs by now :)
ralferoo
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Post by ralferoo »

IronPeter wrote:1.) linux/otheros have pretty full access to the gpu via undocumented functions and hypervisor holes. Via documented functions we have only weak 2D acceleration.

2.) GPU access via holes and undocumented functions is still active in the latest firmware.
It's probably also worth noting that nothing in the hypervisor has been documented. Everything we know about the hypervisor is from actual usage based on the linux modules Sony themselves have contributed.

We didn't know about the possibility of accessing the RSX at all from the first linux ps3fb driver, only when a more recent verison came out did IronPeter pick up on the (still undocumented) change of usage.

Without any documentation available at all, all we really have is from guesswork and probing the methods with test data.

It's possible that 3D was part of the linux plan all along - there are certainly a lot of unkowns in our current understanding of the hypervisor interface.
IronPeter
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Post by IronPeter »

jonwil, the OpenGL driver is very hard to write.

AFAIR, nouveau roadmap is "accelerated quake3 in year". These guys have all information about NV hardware, but amount of work is incredible.

SPU OpenGL driver is a beast also. Many years of development. 2-3 years for single developer, I think.
ps2devman
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Post by ps2devman »

Well if spu-based and rsx-based solutions could be compatible (at some high level entry points) that would be a safety belt in case Sony roars...

Unfortunately there is an ugly policy change in the highest ranks of Sony.
I have the strong feeling big bosses there just got incredibly jealous of Nintendo financial performance. I think they realized selling low tech toys is much more profitable that selling super computers. So I'm afraid but I think the ps3 hardware striptease will go on until the very bottom limit.

Ken Kutaragi (the father of playstations, and main tech boss at Sony) and Izumi Kawanishi (Sony Computer Entertainment Chief Technical Officer) have been thrown away into golden closets, but in practice, they aren't any longer part of decision loops... These 2 geniuses really wanted the ps3 to be the ultimate -low cost, compared to very expensives PC's- computer...

Thus... Not sure we should expect anything good from Sony itself. I wonder if folder@home would have been created and inserted into ps3 firmware if this policy change occured earlier...

Good example of money driven thoughts leading to... more intelligent future deny. Let's all get rich and... die from stupid lethal environment...
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