[Arm-netbook] mali gpu reverse engineering lkcl may ignore

[zap]

On 06/17/2017 09:39 AM, David Niklas wrote:
> On Wed, 31 May 2017 00:16:42 +0200
> sam via arm-netbook <arm-netbook at lists.phcomp.co.uk> wrote:
>> On 30/05/17 22:48, doark at mail.com wrote:
>>> Well, I'd put ten dollars to a campaign like this without a HW reward.
>>> I'm assuming that beings that there are so many Mali GPUs and hacker
>>> boards out there that other people would also be very interested in
>>> this. What would I need to know to do this?
>>> Quick, point me to the books!
>>> No, really, I would do such a thing, I don't have a lot to loose,
>>> though for free I'd be taking my time...
>>> But still, I'd need an education.
>>>
>>>  
>> Start from the existing code http://limadriver.org/
>>
> I understand that I understand very little about this process so please
> read this with hearty laugh prepared.
>
> Whereas other older people have gone from simple reverse engineering
> projects to more difficult ones I have come into the game late when all
> the projects are the most difficult.
> Let me assume that the GPU is a RISC model and uses 8-bit instructions.
> Then it would have a total of 255 instructions (the 256th would be all
> zeros and be a no-op because the wires on the line need a way to tell if
> they have an instruction on them and that is the most power conservative
> I can think of).
> Now let use assume that if the signed bit is set that the GPU receives an
> instruction to set an internal option.
> All that I could probably learn from the lima driver and also some idea
> of how the 2D rendering engine works and what it's instructions are.
> Now the questions come up:
> 1. What are the options for the 3D engine?
> 2. What are the instructions for the 3D engine?
> 3. How do the 2D, 3D, and video (de|en)code engine fit together?
>
> To sum it up, I don't think it's as simple as downloading the code,
> signing up for the mailing list, and coding. It might be, someone could
> have left full specs laying around waiting to be turned into mock-up code
> and then real code; but I doubt it.
> That's not to say I will not try, but I just don't see this as a very
> productive path.
>
> I suffer from the black box discouragement effect. Someone builds a black
> box, then a bigger black box, then an even larger black box; eventually
> no one knows how it works inside, even the people who designed it
> understand only a relatively small part.

IF you can figure out how to reverse engineer the 3d engine, ikcl would
be very happy I am sure. But I get the feeling from him that it is
nearly impossible to do this.

Not sure why... but yeah... RK3288 with 3d engine would be cool I will
admit that. or an even later more compatible processor.

Still, I think you have an uphill battle for that.

ps, I don't have much reverse engineering experience at all, so what I
am suggesting, could be easier or harder.

I just don't know. xD



> Sincerely,
> David
>
> _______________________________________________
> arm-netbook mailing list arm-netbook at lists.phcomp.co.uk
> http://lists.phcomp.co.uk/mailman/listinfo/arm-netbook
> Send large attachments to arm-netbook at files.phcomp.co.uk