Who Actually Plans To Use The Second Cpu??

[Captainbubby]

Hi all,

I'm not a coder myself, trying to learn flash so when when Flash runs better under the 2x I can make some stuff for that.

Anyway, from my searching I've seen some stuff which is about a month + old, including Squidge benchmarking the 2nd CPU and finding that it performed at 190 % when compared to the original one CPU benchmark.

Now again, I could be totally wrong as I'm not a dev (much to my dismay) and don't have my finger on the pulse of SDK updates and what not.

Just curious, can the 2nd CPU currently be utalized? And do any devs plan on utalizing it when it becomes possible, from what I would gather it'd be a rather large pain in the arse, because utalizing it would require a total recode. (So I have read)

Hey that sounds cool; "Total Recode" like a geeky Shwarzenneger movie.

"Cohagen you've won, give these people SDK's"

 

[whiskthecat]

I myself was also wondering this. I also wanted to know how badly it would effect the battery life.

 

[craigix]

Its certainly being used in commercial projects.

 

[OrR]

 

[Firefox]

I've got a simple test program running on it already, and sometime in the next week or two I hope to have part of the Jaguar emulator I'm porting moved into the second CPU.

I'm planning to do a simple little 3D shoot 'em up at some stage (my schedule's pretty full for the next few months, but I've got quite a lot of the engine prototyped and working under Linux + SDL already) and I'd thought to use the second CPU as a polygon renderer (though not under SDL).

 

[Captainbubby]

So, is the 2nd CPU is accessable to coders with the current SDK and firmware release? I would see that that as essential for some of the more powerful emulators such as the PSX.

A Jaguar emulator sounds great, best of luck and hope it goes smoothly.

Craigx, I'm excited to see the results of these commercial projects as I'd love to see what the Gp2x is capable of (apart from emulation of course, I mean the sort of non-rom games that can be made). Despite there being no 3D hardware the Gp2x is a powerful machine when it's potential is tapped.

 

[ingrin]

I've got a simple test program running on it already, and sometime in the next week or two I hope to have part of the Jaguar emulator I'm porting moved into the second CPU.

I'm planning to do a simple little 3D shoot 'em up at some stage (my schedule's pretty full for the next few months, but I've got quite a lot of the engine prototyped and working under Linux + SDL already) and I'd thought to use the second CPU as a polygon renderer (though not under SDL).

​

For clarity, this Jaguar emulator is focused on Tempest 2000 and a few simiar games only right? Or has it blossomed into an all-out Jaguar emulator?
Regardless, it will be an impressive acheivement...

 

[mittens]

I believe Rlyeh's Minimal library already support for 2nd CPU.

 

[SolidSnake]

I believe Rlyeh's Minimal library already support for 2nd CPU.

​

yes, but for what?

Like somebody already said in the thread, if the psx emulator could use the full power of the second CPU for rendering for example, it would reach an incredible speed i think

 

[Firefox]

For clarity, this Jaguar emulator is focused on Tempest 2000 and a few simiar games only right? Or has it blossomed into an all-out Jaguar emulator?
Regardless, it will be an impressive acheivement...

​

Yes that's right, it was designed specifically to run Tempest 2000 and the VLM/CD BIOS.

I hasten to add that I didn't create it, I just ported it from Windows to Linux.

 

[Radek]

I believe Rlyeh's Minimal library already support for 2nd CPU.

​

yes, but for what?

Like somebody already said in the thread, if the psx emulator could use the full power of the second CPU for rendering for example, it would reach an incredible speed i think

​

The 940T core is waiting to be utilised but it's not making the gp2x SMP system. It hasn't a MMU and its caches are smaller. Still uses might be vast and it's already used for parsing and controling data for video processor when playing movies.

I hope the others helpers what gp2x has will get some attention too (especially videopostprocessor and 2d accelerator).

 

[skeezix]

I've got a simple test program running on it already, and sometime in the next week or two I hope to have part of the Jaguar emulator I'm porting moved into the second CPU.

I'm planning to do a simple little 3D shoot 'em up at some stage (my schedule's pretty full for the next few months, but I've got quite a lot of the engine prototyped and working under Linux + SDL already) and I'd thought to use the second CPU as a polygon renderer (though not under SDL).

​

Theres too many good words in this post; yum!

(Jaguar!)

jeff

 

[maffoo]

So, is the 2nd CPU is accessable to coders with the current SDK and firmware release? I would see that that as essential for some of the more powerful emulators such as the PSX.

Could it be used for things like Amiga emulation? I've been pondering this for a few days, maybe it could be used to emulate, say, the CPU with one processor and the custom chips with the other.

(As someone with no programming experience, I don't know if it would be possible but it would be interesting to see if it would work )

 

[SolidSnake]

but using the second core as a dedicated video processor for example, would not speed up the thing?

The second core could (technically) be used for what?

 

[Radek]

but using the second core as a dedicated video processor for example, would not speed up the thing?

The second core could (technically) be used for what?

​

The second core is just another Am9 based cpu like the first. It can execute normal code so it can be running whatever a programmer could imagine. The hard thing is to parallel load on both cores equally. Otherwise the benefit of dual cores is somewhat limited.

There are many different strategies to handle such situation. Alternate frame rendering, screen splitting, functional splitting (2nd cpu could mix audio for an example). But it's not easy and very often will require total rewrite of aplication.

 

[God Ginrai]

unless someone could write a program that runs in the background and allocates functions in programs to one processor or the other to maximize speed.

 

[Ferentix]

So now I'm really confused I haven't been able to keep up with everything over the last few weeks/month either, and the last I heard, some were saying one could not have both processors working at the same time, others were saying you could, and if I remember rightly, you had to put instructions for the second core in a specific area of the RAM and those for the first in a different one (and there was an area that both could access) so I guess that the second processors PC starts off at something other than 0?

I've been reading up on ARM assembly recently so I know a little about the way a single ARM runs, but I still have limited knowledge especially on dual CPUs (in any configuration), but it seems to me that one would have to use the primary processor to pass instructions into RAM for the secondary processor to execute? Or is there a way to have part of the binary passed automatically to the second processor?

 

[Dingo_aus]

I think the 920 has to control the 940. the 940 doesn't have a MMU nor I think direct access to hardware interupts etc so the 920 has to inform the 940 where in memory code is to be executed and then let it run

 

[aapje89]

unless someone could write a program that runs in the background and allocates functions in programs to one processor or the other to maximize speed.

​

wasnt some dev (squidge?) saying that this was possible?
then it would be much easier for devs .

 

[Vimacs]

Thats of course impossibil.

However, the 2nd cpu can be used since the first day, its about fetureing out inteligent ways/tasks to use it(for).
So far most gp2x stuff is just simple ports, barly optimized for gp2x at all, let alone the 2nd core.

But when time goes bye more and more gp2x optimized software will pop up, and the 2nd cpu will find its use, as well as the hardware 2d function wich are currently incoperatet in many libs.
For now a hardware accerlated sdl will give some ports a "free and easy" boost.