Gba Emu

[Efompor]

This sounds very promising. How large is the GBA's BIOS anyway? If he is trying to cram in at least the original GP32 BIOS & the GBA BIOS at the same time, will there be enough room? And with acess directly from the BIOS, would the SMC reading speed be speed up enough to extent the size of ROMs used?

yeah I was thinking the same thing. Where do you put the emulator, in the 512kb of ROM? sorry I dont know too much about the GP32's BIOS :huh:

 

[Sonic-NKT]

the normal gba bios is very small i think... i have one on my hd and its 16kb.
dont know if i am right, perhaps there is another file... im not sure

 

[Sponge BoB]

plus its not really an emulator as such, more using the gp32s modified bios to interpret the gba games(i think)

 

[Sonic-NKT]

news!!!!

here is the translated version:
I emulated my first rom this weekend, good it agreed right a rom which posted an image in mode3, but good it goes well.
I finished modes 3,4,5 and I started mode 0 well, but it is necessary still that I test them.
I have still other problems to solve and a ton of optimizations to be made, but a priori it y nothing insurmountable.

and here the original:
j'ai émulé ma première rom ce week-end, bon d'accord c'était juste une rom qui affichait une image en mode3, mais bon ça marche bien.
J'ai fini les modes 3,4,5 et j'ai bien entamé le mode 0, mais il faut encore que je les teste.
J'ai encore d'autre problèmes à résoudre et une tonne d'optimisations à faire, mais à priori il y rien d'insurmontable.

sounds very promising
i cant wait to have this running on my gp

 

[MojoJojo]

But given that the gamepark bios doesn't occupy the normal area for a bios to do so in memory, why would you actually need to reflash in the first place? As long as they take up different bits of memory, you should just be able to allocate the GBA bios the exact area where it normally would reside and avoid all danger of GP-Death that way.

Even stranger when you consider that the bios functions are accessed through SWI calls*, so it doesn't matter where they are. Most of the bios calls are fairly simple. If you discount the sound (which I would until everyhting else close to working), the only other stuff is some fairly standard decompression routines. Considering there are copies of the GBA bios disassembled and nicely documented (and it's mostly stuff which should port fairly easily) I don't think emulating the GBA bios is very hard. Not compared to, for example, all the graphics hardware.

And this decompiling and recompiling to pure ARM stuff. I don't see the point in that at all. I think it's a non-trivial operation (ARM instructions twice the size, all your addresses get messed up), and the only thing it should make a difference with is timing.

It may just be that I'm paying too much attention to bad translations and rumours, but I'm beginning to think we're having our leg pulled.

Can you think of any other emu writer who would say they were working on the most wanted emulation, at such an early stage in development? Hmmm?

I hope I'm not doing the bloke an injustice. Just some things just don't seem to add up.




I found a few examples of homebrew code messing around to get direct access to the BIOS (its marked unreadable, as some copyright protecting code in there), but it's fairly unlikely that official licensed code would do anything like this

 

[Alpha2]

The issue is whether or not youcan believe the solution is this easy and no one;s attempted to try it this soon. In a mattler of less than a month this personalhas presumably made the GP pretend to be a GBA without an emmulator.

He could have done this, he says it works in certain modes, the question is how well does it work? is it glitchy is it moving 2 fps? are the colors right? are sprites corrupted? In the end just how much will he need to do to complete it with decent speed and eventually sound? Will there be enough room in the systems memory to handel special functions in the GBA?

There are a lot of questions to resolve before it becomes truely a great thing

 

[pip]

For those who wonder, the line Sonic translated to "but a priori it y nothing insurmountable." (huh?) actually means "but nothing seems impossible"

Any how, if this project goes well it will be the best thing to hit the GP32 since the FLU

 

[unlucky]

This would be pretty frikking amazing i would hope its not fake the idea seems simple enough but then i understand nothing of emulation and very little abotu programming etc etc etc etc

 

[khephren]

The issue is whether or not youcan believe the solution is this easy and no one;s attempted to try it this soon. In a mattler of less than a month this personalhas presumably made the GP pretend to be a GBA without an emmulator.

He could have done this, he says it works in certain modes, the question is how well does it work? is it glitchy is it moving 2 fps? are the colors right? are sprites corrupted? In the end just how much will he need to do to complete it with decent speed and eventually sound? Will there be enough room in the systems memory to handel special functions in the GBA?

There are a lot of questions to resolve before it becomes truely a great thing

Yeah their are an awfull lot of questions. As for this solution not being tried, this form of native code+emulating the other hardware has been talked about no end of times on here, but no one has ever attempted it, it's a very different (and harder) approach than taking a PC emu and bringing it over, a lot of the work would have to be from scratch. (I guess it's most similar to shapeshifter mac emu on the Amiga, runs the cpu data direct, and emulates other mac hardware if it has to) Most of our coders are in full time work/school and don't have the time for it, whereas porting something quick, and editing it as when you can is a lot easier.

Whether it's real... difficult to tell, You can normally tell a lamer from his first couple of posts... except when it's a bebelfish translation

 

[Jr2swiss]

What does W.I.P. stand for?

 

[Efompor]

work in progress

 

[TelcoLou]

Work In Progress.

 

[Swiss_Cheeseman]

Water In Pool

 

[shotaway]

What does W.I.P. stand for?

women in pantie's

 

[divadsci]

What Is Pie

 

[ralp99]

no no , let's go back to women in panties (....)

 

[divadsci]

subject titles usually refer to their content

 

[watzza_uppa]

WHAT THE F**K
I log in to see 2days topics and im greeted by women in panties......

Tell Me More!!!

 

[Rico]

Well the worrying part is, he starts the post with 'I have an idea (or concept rather)...' and he doesn't have much GP32 programming skill. BUT I STILL LOOK FORWARD TO THIS!

enf65 has done some research, from the same thread:

- He has found that it's not an illegal emulator
- He reads a lot of technical stuff on the GBA
- From The Fish(tm) :

SOMETHING IS WORKING!!!

I emulated my first rom this weekend, good it agreed right a rom which posted an image in mode3, but good it goes well. I finished modes 3,4,5 and I started mode 0 well, but it is necessary still that I test them. I have still other problems to solve and a ton of optimizations to be made, but a priori it y nothing insurmountable.

Some commentary on his development:

I began my decompiler ARM7TDMI already well, but I realiserealises that the transformation of a rom, even just if it is necessary to change some addresses memories, with difficulty will be done entirèrement automatically. Another point: there is an interruption (I forgot its name) who intervene when a definite zone of the memory is read or written. It would be thus easy to intercept the writings with the peripherals of the GBA (image, its...).

I almost finished all the interface (menus, loading of the roms...) and I will tackle the greatest part: emulation. For the moment I program very out of C considering it is much faster and more clearly. When I would have very finished I could optimize the critical functions out of assembler. I think that I will try to use sources of emulators gba which already exists (style visual servant boy advance, or other).

I have another more technical problem: to configure la(ou it, I do not know too much) MMU, I need to be in a privileged mode (style as after a software interruption SWI). Is there a function of the bios for that? Or better is there a function of the bios for directly configuring the MMU? I have some sources which use the MMU, I still will have to seek a little... Until now, I have to pass more half of time to read docs, it is shitting.

Mode 7 will be supported if emulation works!

On the GBA, mode 7 is already an emulated mode, (mode 7 exist only on the SNES). Thus not need to do it

Good luck to enf65, looks like things are truly on their way

 

[Tobriand]

Certainly sounds that way. As I've said before, any first releases I wouldn't expect a huge amount from, but this is potentially amazing. And it is very encouraging to hear news that actually sounds reasonable, as opposed to simply "I've made full speed X emulation and it'll be released 9 seconds ago... what? Oh, the server must have gone down under the load; it isn't *really* 404ing" and such.

The next few months will be exciting in potentia!