Under The Hood: 200mhz... 385mhz... ;)

[foft]

GPH may not have a choice. MagicEyes (the manufacturer of the chip) provide the chips and some drivers for Linux and Windows CE. GPH decided on Linux, so they may not actually know anything about how the two processors work internally - they may simply be using the API given to them by MagicEyes, and provide an abstraction of this API with there own SDK.

The MagicEye's API isn't public, and they refuse to give out any detailed information about there SoC, so it may take a lot of reverse engineering to find out if it is even possible to run code on the second processor.

No doub't doubt we'll find out soon after the machine is released.

​

Do they really refuse to give out the data book? I was hoping it was just a case of registering on the site. I'll be very disappointed if they refuse... What made the GP32 great was largely the freely available databook for its main chip.

Anyway I think you can run code on the 940T. In the docs it says "Meanwhile, ARM940T CPU can be used as a programmable coprocessor to share ARM920T CPU’s program overhead by taking part in user specific software functional requirement treatment, the embedded Video Processor controlling, and so on.". Sounds like it can run user specified software. Fingers crossed!

Mark

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edit: In fact they go even further... "The dual CPU architecture offers the ultimate flexibility when implementing user proprietary and/or differentiated solution easily and quickly without paying additional cost. For example, customer can use one out of two CPUs to implement his own specific video pattern recognition algorithm while without disturbing the other CPU in managing OS and audio algorithm.". Sounds like the "customer" can use both CPUs at least. So unless GPH disabled it explicitely...

edit2: Well I asked GPH - post 722. Seems no-one had asked on their message board! Hopefully they will add it to their FAQ.

 

[Squidge]

Well, there's a number of people that have requested the information over the past few months, some even from companies where the chip could be used in one of there products, but they have yet to receive a positive response.

However, I think Craig's going over to see Gamepark Holdings soon, so no doubt he'll be asking them if it's possible, and we'll get something confirmed.

 

[Inopia]

squidge: the video acceleration is done with the video codec blocks in the chip itself, so just a a pmp the gpx2 would be fine without the 940T. However the gamepark guys told us that this chip at 200mhz is faster than a 400mhz single core arm. This kinda implies the 940 is programmable, unless they're just talking about video.

But to be quite honest, I think it'll be possible to run code on the 940. I don't think that because the drivers are closed the 940 is locked out. Usually when people hook two cores together it's done in a standard way we'll be able to figure out (why re-invent the wheel?) And even if it's hard, we have freaks like mr_spiv and darkfader to work it out for us

 

[Tobriand]

So really a question of when rather than if...

It'd just be sooo much nicer if they could just open it up from the start and not force us to hack the chip to get it to do what eople need it to; that is, after all, where the benefit lies of an OS console in theory over and above a closed system...

 

[DaveC]

squidge: the video acceleration is done with the video codec blocks in the chip itself, so just a a pmp the gpx2 would be fine without the 940T. However the gamepark guys told us that this chip at 200mhz is faster than a 400mhz single core arm. This kinda implies the 940 is programmable, unless they're just talking about video.

But to be quite honest, I think it'll be possible to run code on the 940. I don't think that because the drivers are closed the 940 is locked out. Usually when people hook two cores together it's done in a standard way we'll be able to figure out (why re-invent the wheel?) And even if it's hard, we have freaks like mr_spiv and darkfader to work it out for us

​

I think Darkfader has gone to DS or PSP developement. Hopefully he will have enough interest in the GPx2 to pry him away from the DS enough to crack the chips in GPx2. If he can hack the DS with no info, he can most likely hack this too.

 

[Squidge]

I think all of us, including DarkFader, Spiv, etc, just hack on whatever interests us at the time. I even bought a Gizmondo with no games, simply to hack about with, and several development boards, etc.

 

[DaveC]

Hopefully the GPx2 will interest some of you hacker types too. If you really could use that second CPU for anything, perfect SNES would not be impossible even at only 200 MHz.

 

[Squidge]

Hopefully the GPx2 will interest some of you hacker types too. If you really could use that second CPU for anything, perfect SNES would not be impossible even at only 200 MHz.

​

Are you ok DaveC, just as I can't seem to find anything negative in what you've just written

But yeah, us hacker types are interested in the GPx2

 

[Julius]

Hopefully the GPx2 will interest some of you hacker types too. If you really could use that second CPU for anything, perfect SNES would not be impossible even at only 200 MHz.

​

Are you ok DaveC, just as I can't seem to find anything negative in what you've just written

But yeah, us hacker types are interested in the GPx2

​

Confess, you evil hacker... you hacked DaveC's account and posted something positive in his name

 

[moz]

Hopefully the GPx2 will interest some of you hacker types too. If you really could use that second CPU for anything, perfect SNES would not be impossible even at only 200 MHz.

​

Are you ok DaveC, just as I can't seem to find anything negative in what you've just written

But yeah, us hacker types are interested in the GPx2

​

great to read

 

[Prophet]

Interesting. So then my idea may work out afterall. Being able to split the processing load between the CPU's to speed up emulation, as has been done on PSP.

Well, fingers crossed. if this is doable, then GPX2 will be pretty powerful for emulating 2D hardware. And that 64MB is damn sweet.