Gpsp Smc Game Problem

[maddrone]

I use gpsp as GBA emulator for a long time, on psp and my Dingoo. It plays most game perfectly.

But when I play the DOOM II and some other game , it really slow and unplayable.

I am a Developer myself and I found some descrption about this problem on Exophase's(the Gpsp Author) blog long time ago.

These are what he said:

"
Anyway, even if only a few bytes are changed, with the way things work now it'll cause everything that has been compiled to be flushed. So I came up with a solution to help change this. Now I have two buffers for RAM code, a "static" one and a "dynamic" one. There are counters for code regions associated with self modifying code writes. When something has been written to enough times the region changes from static to dynamic. Now when code in that region is recompiled it will go to the dynamic buffer instead of the static one. The consequence of this is that when this code is modified in the future only the dynamic buffer needs to be flushed. If the amount of code being rewritten is relatively small then this dynamic region will be minimized.

"


It seems that he had a solution for this kind of problem.

The question is:

Is there any released version of Gpsp or any console port has solved this problem?

sorry for my poor english, thank you .

 

[CloverGruff]

It'd be nice to have a proper GBA emulator. I am particularly interested in more technically advanced games, like Kill-Switch, Max Payne.

 

[sebt3]

It'd be nice to have a proper GBA emulator.

Sure that sound to be the best reply ever to make to this thread to be sure nobody will work ever on the request of maddrone

 

[CloverGruff]

It'd be nice to have a proper GBA emulator.

Sure that sound to be the best reply ever to make to this thread to be sure nobody will work ever on the request of maddrone

Ok, I apologise, that probably didn't sound so nice anyway.

All I meant was that while gpsp is awesome and it does indeed run a lot of games quite well, it would be great if it actually got some sort of update.

 

[Optimus]

It'd be nice to have a proper GBA emulator.

Sure that sound to be the best reply ever to make to this thread to be sure nobody will work ever on the request of maddrone

Ok, I apologise, that probably didn't sound so nice anyway.

All I meant was that while gpsp is awesome and it does indeed run a lot of games quite well, it would be great if it actually got some sort of update.

I never felt the need to play Doom 1 or 2 on a GBA emulator, since there is already a PC port with much better resolution and speed (I'd rather see a new PCSX version that plays Doom, that doom version is quite unique and I wonder how it will feel like in the Caanoo or tv-out if speed is hopefully good too). But I am not against an update even though I am 99% satisfied from GPSP. I am wondering what is the difference that makes Doom 1 play well on the GPSP and not Doom 2, since they seem to have the same engine and developed by the same team (Torus games iirc).

Oh, that thing not enough people mention. When I got the latest GPSP, something happened and when I overclock at higher speeds (700 or more) then the game and sound plays faster than 100%. Sometimes it's funny (high pitched sounds, too fast gameplay) but sometimes you really want to play the game in normal speed. If you underclock at original 533Mhz then everything is fine but at specific moments in game things slow down and you really need that overclocking boost without it destroying sound and gameplay. I think this also might have something to do with newer firmware versions, does anyone know more about this problem and maybe I should downgrade my firmware to get things correct (I also tried older versions of GPSP, showing other problems, like the opposite problem of slowing down timing to less than 100% with the latest firmware. I remember in the past that I was fine with one of these older GPSP versions)

 

[Exophase]

I worked on different self-modifying code strategies later than the blog posting, during the summer of 2008. The approach was more complex than what I outlined in the blog. The codell had some problems (occasional crashes in Golden Sun 2, the game I was testing since that was pretty SMC heavy) and it was very difficult to debug. At this point I got tired of working with gpSP's codebase and would have preferred to work on something totally different if I did GBA emulation.

I could post what I wrote, but due to the instability of the solution and the lack of any ARM port (I was testing entirely on x86, ARM/MIPS/whatever would have needed some more codegen and maintenance code) I doubt anyone would be able to put it to very good use.

 

[maddrone]

I worked on different self-modifying code strategies later than the blog posting, during the summer of 2008. The approach was more complex than what I outlined in the blog. The codell had some problems (occasional crashes in Golden Sun 2, the game I was testing since that was pretty SMC heavy) and it was very difficult to debug. At this point I got tired of working with gpSP's codebase and would have preferred to work on something totally different if I did GBA emulation.

I could post what I wrote, but due to the instability of the solution and the lack of any ARM port (I was testing entirely on x86, ARM/MIPS/whatever would have needed some more codegen and maintenance code) I doubt anyone would be able to put it to very good use.

hi Exophase

Thanks for your reply

I also found that the yongzh version gpsp in Android seems solve such SMC problem (I dont know if he has your permission to release the Android gpsp),

or there are also problems in his solution but I didnot occur?

Maybe you could release the Newest gpsp source to help other platform porting(PSP, Dingoo, GP2x etc), it seems you have fixed some bugs since your last

release 2-3 years ago.

Or you could make a new blog release on your gpsp-dev blogspot, let we know what you have optimize in gpsp , after about 5 years time