Guess What? A Port Of Gpsp (gba) To The Gp2x...

Discussion in 'General Talk' started by zodttd, Nov 13, 2006.

  1. DaveC

    DaveC Internal Development

    Joined:
    Mar 4, 2004
    Messages:
    9,208

    Yeah, throw linux out if you can. When you are playing GBA stuff it is not like you need to run USB or anything.

    The only problem is that as soon as the GP2X gets to the point where you can do anything linux is already loaded. I don't know if you can get rid of it at that time.

    Plus you would have to write your own SD card drivers etc. That would probably as much work as writing the emu itself.
    Someone was working on a non-linux simple loader at one time ("HH") but I guess it was abandoned.
    If you did write a non linux loader I bet alot of other coders could use it.
     
    Last edited by a moderator: Dec 17, 2015
  2. Ze_ro

    Ze_ro Member

    Joined:
    Nov 11, 2005
    Messages:
    234
    Location:
    Winnipeg, MB
    I don't pay attention to the PSP emulation community, so I'm unfamiliar with this emulator.... Just for comparison, how fast does it run on a PSP? Is the compatibility good?

    --Zero
     
  3. DaveC

    DaveC Internal Development

    Joined:
    Mar 4, 2004
    Messages:
    9,208
    I just meant native as in you wouldn't have to emulate an ARM since you already have a real ARM CPU. It wouldn't be like a Megadrive emu where you have to translate 68000 instructions to ARM ones. That is what I was getting at.

    I know there are other things keeping GBA stuff from just running. There is the GPU and audio etc. I am just wondering if you could run the arm code natively and emulate the other stuff in spare cycles. The GBA is only like 12 MHz. The GP2X is 20x faster. That is alot of spare time for the CPU. Then you have the second core that could do some simple tasks as well. The resolution is also 1/2 of the GP2X so drawing the fewer pixels is easier. The scary part though is that the GBA is very SNES-like with it's scaling/rotation and transparencies. That could be a bit of an obstacle.
     
    Last edited by a moderator: Dec 17, 2015
  4. Exophase

    Exophase Nothing good will ever come of Exophase.

    Joined:
    Sep 21, 2006
    Messages:
    10,308
    Location:
    Cleveland OH
    DaveC:

    Maybe I don't mean "get rid of Linux" as much as I mean.. circumvent it for a long time. If taking over interrupts is enough it'll be sufficient, I think. As far as files go, you can go back to Linux whenever you need that stuff. It's devious but could work, depends on a lot of other factors of course. The biggest being where the interrupt vectors live (course you'd also need to be in kernel mode).

    True virtualization is not really possible, unless the ARM9's have hidden features I don't know about. There's a subtle distinction that throw a lot of people off, but even though it's ARM->ARM you can't run one on the other because you have to treat certain instructions differently. In particular you have to run the GBA code so it's always in user mode, but make it think it's in whatever mode it's really in. If this can be caught with exceptions then virtualization might be possible. Otherwise a slim dynarec would be used.

    BTW, GBA is 16MHz.

    The video rendering takes a lot of CPU time, but it can be done on PSP decently well, fully software (no hardware acceleration), so at least that won't be a tremendous concern. Frameskip 1 naturally cuts requirements in half so... I wouldn't recommend using it on the second CPU though, it's too tightly linked with the GBA CPU, sharing a memory space.

    Ze_ro:

    At this point gpSP is running most games at fullspeed with perhaps a little frameskip - there are a few games that run very slowly but they probably need certain tweaks to overcome this (games that just don't play nice with dynarec).. compatability is okay. Like 80%. Will be higher in the next version. It's not as compatibly as VBA of course.
     
  5. Vollgasasi

    Vollgasasi Member

    Joined:
    Aug 14, 2003
    Messages:
    347
    then get one, quickly... :p

    and zodttd, seems like davec and epicenter woke some ambition in you lol :)
    good luck mate!

    and davec: thanks for being grown up this time ;)
     
  6. DaveC

    DaveC Internal Development

    Joined:
    Mar 4, 2004
    Messages:
    9,208
    The PSP is 133 MHz faster so I would think the Gp2X would need more help. I was hoping the CPUs being both ARM would help make up the difference.

    Could there be something that the second core could do? I know it helps Megadrive emulation alot. It is used to run the audio emulation, and gives a very nice speed boost.

    80% is pretty good. It is better than the 0% that we have now :p
     
    Last edited by a moderator: Dec 17, 2015
  7. darkman

    darkman darkman unmasked!

    Joined:
    Aug 16, 2005
    Messages:
    758
    Location:
    Kentucky, USA
    :eek: Oh no! I'm going to have to go out and buy another SD card!
    This sounds like something really great! Can't wait! But I will. :)
     
  8. Azalin

    Azalin What was that? It sounded like a, a sound of some

    Joined:
    Aug 16, 2006
    Messages:
    457
    Location:
    British Columbia
    Dear sweet lord, there IS another person who uses Shodan as an avatar!
     
  9. WhiteFalcon

    WhiteFalcon Certified Guru

    Joined:
    Nov 4, 2003
    Messages:
    732
    Location:
    Czech Republic
    Is static recompilation out of the question in this case? I don't know much about it, just asking.

    Sweet news! :)
     
  10. Iorgy77

    Iorgy77 emu parasite kid

    Joined:
    Oct 17, 2003
    Messages:
    2,068
    Location:
    Melbourne, Australia
    Fantastic news this would be great! :)
     
  11. Epicenter

    Epicenter Very Active Member

    Joined:
    Oct 9, 2005
    Messages:
    2,068
    Location:
    USA
    Zodttd, if you hadn't noticed, I sent you a couple of PMs.

    Oh, and to whomever put the fellow with his head up his ass in my signature, grow up. This is something I'd expect from a Shadow the Hedgehog fan forum occupied by 6 year olds.
     
  12. AcidiC

    AcidiC Member

    Joined:
    Jan 1, 2006
    Messages:
    277
    Location:
    Sydney, Australia
    Great news, thanks and good luck Zodttd
     
  13. PokeParadox

    PokeParadox Founder of Pirate Games - Penjin Coder Staff Member

    Joined:
    Dec 8, 2005
    Messages:
    6,512
    Location:
    UK
    Good luck Zoddy! :p
     
  14. Vimacs

    Vimacs Don't be evil!

    Joined:
    Oct 23, 2003
    Messages:
    5,211
    Location:
    Germany
  15. garengarch

    garengarch Member

    Joined:
    Oct 1, 2005
    Messages:
    178
    Location:
    N.Scotland.
    Great to hear Zod, standing by if you need alpha testing...
     
  16. Phil

    Phil FAPPO!

    Joined:
    Jun 16, 2003
    Messages:
    968
    Location:
    Ireland
    zodtdd, you always make the best news posts.
     
  17. reaper79

    reaper79 Rectum? Damn near killed ''em!

    Joined:
    Apr 20, 2005
    Messages:
    618
    Location:
    Ohio, US
    If Exophase and zodttd are going to be working together to bring proper gba emulation to the GP2X, perhaps a "donate to get Exophase a gp2x" fund could be set up to try and get him a gp2x. I believe Squidge received his gp2x in a similar manner?
     
  18. EvilDragon

    EvilDragon Administrator Staff Member

    Joined:
    Mar 4, 2003
    Messages:
    19,785
    Location:
    Ingolstadt
    Oh, that's easy. Remember Robsters Firmware Updater? That does exactly that :)
    Since the first version.
     
    Last edited: Dec 17, 2015
  19. Godmil

    Godmil Active Member

    Joined:
    May 6, 2006
    Messages:
    578
    Excellent news... hope this project goes well :)
     
  20. XaMMaX90

    XaMMaX90 Member

    Joined:
    Jun 6, 2006
    Messages:
    217
    Great news! I love you zodttd =)
     

Share This Page

Loading...