Idea for an Xbox 360 Emulator - Page 2

fischkopf · July 4th, 2012, 18:08

Quote:

Originally Posted by JoaoHadouken

hmmm... I see your point, BlueShogun. I thank you by the information and by the kind of questions that I have to ask myself to start working on a emu... I know these things are really important... but let's not put the cart before the horse... I don't intend to build an Xbox 360 emulator right now, it was just an idea I have had a year ago and wanted to share now... I don't know when I'm going to step into Xbox 360 emulation, perhaps I can help you in Xbox 1 emulation first... I don't know yet. Any way, your reply was really useful. Thanks!

Yes, better start with Xbox 1 emulation, and only if that's perfectly working (probably never?) then go on from there.

-Ashe- · July 4th, 2012, 19:19

Quote:

Originally Posted by blueshogun96

You guys ONLY focus on hardware and think almost nothing of the software aspect.

Actually it's the other way around, I'm working on a high level emulator, so I don't really care about how the hardware works

Quote:

Originally Posted by blueshogun96

Besides the fact that you have to emulate 3 of those suckers, what about the VUs? They use a special instruction set called AltiVec (IIRC).

Power ISA reference document, Book 1, chapter 6...

**blueshogun96** · July 5th, 2012, 08:20

Quote:

Originally Posted by -Ashe-

Actually it's the other way around, I'm working on a high level emulator, so I don't really care about how the hardware works

Power ISA reference document, Book 1, chapter 6...

You can't even do HLE if you don't understand certain parts of the hardware. HLE is not a magic solution to avoid the hardware aspect completely (Cxbx is a prime example). I haven't looked into how the command buffers work yet, but if it's anything like push buffers on Xbox1, you'll have to understand a little bit about the GPU in order to effectively decode them.

How far have you gotten with your HLE emu?

Quote:

Originally Posted by JoaoHadouken

hmmm... I see your point, BlueShogun. I thank you by the information and by the kind of questions that I have to ask myself to start working on a emu... I know these things are really important... but let's not put the cart before the horse... I don't intend to build an Xbox 360 emulator right now, it was just an idea I have had a year ago and wanted to share now... I don't know when I'm going to step into Xbox 360 emulation, perhaps I can help you in Xbox 1 emulation first... I don't know yet. Any way, your reply was really useful. Thanks!

Sorry if I sounded angry, but I just get tired of people throwing ideas without any idea how to do it themselves of even knowing if it's feasable. Not saying you're one of those people, but still, sometimes these threads can get really annoying and fast... especially when you've listed your own feasible plans time after time again.

I still stick by my idea of a PPC64 -> x86-64 static recompiler.

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Last edited by blueshogun96; July 5th, 2012 at 08:21.. Reason: need automerger

-Ashe- · July 5th, 2012, 10:51

Quote:

Originally Posted by blueshogun96

How far have you gotten with your HLE emu?

So far I worked on it for about 2 months starting in September last year, then I picked it again 2 weeks ago... so not very far

I can load executables from ISO files and STFS packages (and extract pretty much every single piece of information they have, but that's not really emulation unless I want to write my own dashboard), and execute simple things like a hello world or a spinning triangle...

Reversing the buffer with the GPU commands takes time, and I'm working on the debugger far more than the 3D parts of the emulation at this point, so I'm not really expecting to get anything graphical running anytime soon...

Apart from those simple things, gamepads are working (but those are basically the same xinput calls anyway), creating threads and other basic features like those (mutex and such), some networking (the winsock-ish API, not the Xbox Live stuff, obviously), etc...

**blueshogun96** · July 5th, 2012, 18:42

Quote:

Originally Posted by -Ashe-

So far I worked on it for about 2 months starting in September last year, then I picked it again 2 weeks ago... so not very far

I can load executables from ISO files and STFS packages (and extract pretty much every single piece of information they have, but that's not really emulation unless I want to write my own dashboard), and execute simple things like a hello world or a spinning triangle...

Reversing the buffer with the GPU commands takes time, and I'm working on the debugger far more than the 3D parts of the emulation at this point, so I'm not really expecting to get anything graphical running anytime soon...

Apart from those simple things, gamepads are working (but those are basically the same xinput calls anyway), creating threads and other basic features like those (mutex and such), some networking (the winsock-ish API, not the Xbox Live stuff, obviously), etc...

Excellent. How are you emulating the CPU? Static-rec, JIT, what?

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-Ashe- · July 5th, 2012, 19:05

Oh no right now it's just an interpreter, I'd rather have some kind of reference point I can compare with before moving to static recompilation...

JayFoxRox · July 5th, 2012, 21:36

Sta-rec using llvm should actually be easier than an interpreter. It's a little bit harder to get started but once you have the base working it would be easy to debug and really fast. You could also detect code patterns more easily.

-Ashe- · July 6th, 2012, 00:20

Yes but I don't want to use llvm, it's far more fun doing it yourself

**blueshogun96** · July 6th, 2012, 05:31

I recommend taking JayFox's advice, but suit yourself.

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-Ashe- · July 6th, 2012, 06:11

I've worked on many compilers and recompilers in the past, and it's a hobby, so not sure why I'd use a library to do what I wanted to code this emulator for in the first place

JayFoxRox · July 6th, 2012, 13:42

llvm could also only provide the optimization passes etc. which are VERY complex. It'd take years to implement only parts of those.
For a project like this performance is critical, even if you don't want realtime emulation.

llvm is not a drop-in PPC emulator either, so there is still plenty of work, very similar to normal interpreter development (Converting your high-level code to llvm code).

But at the end of the day its obviously up to you.
Good luck with your project anyway.

Is there a repo already? Or do you have any screenshots?

-Ashe- · July 6th, 2012, 19:35

It's not opensource, and I'm not sure a screenshot of a spinning triangle would be very useful

**blueshogun96** · July 6th, 2012, 22:51

Quote:

Originally Posted by -Ashe-

I'm not sure a screenshot of a spinning triangle would be very useful

It would actually. Makes your project more believable (not that I'm doubting you). Face it, to the uneducated people who still don't believe it's possible, they can't walk by faith alone. Whether you want to prove a point is up to you.

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-Ashe- · July 6th, 2012, 23:13

Yeah, I guess I just don't care enough about what people might think of my personal-boredom-killing-hobby

But sure when I have something more interesting to show (maybe the least technically complex indie game displaying its main menu) I'll post it around here

**blueshogun96** · July 7th, 2012, 04:54

Quote:

Originally Posted by -Ashe-

Yeah, I guess I just don't care enough about what people might think of my personal-boredom-killing-hobby

But sure when I have something more interesting to show (maybe the least technically complex indie game displaying its main menu) I'll post it around here

Yeah, I wouldn't care either. One of the greatest and most interesting points for me in an emulator's life is the day that it shows some of the little stuff like a triangle or a few boxes. I'm just making excuses for you to show me a screen of your project.

... please?

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July 5th, 2012, 19:05	#26
-Ashe- Registered User Join Date: Oct 2011 Posts: 189	Oh no right now it's just an interpreter, I'd rather have some kind of reference point I can compare with before moving to static recompilation...

July 5th, 2012, 21:36	#27
JayFoxRox Registered User Join Date: Dec 2010 Location: Germany Posts: 35	Sta-rec using llvm should actually be easier than an interpreter. It's a little bit harder to get started but once you have the base working it would be easy to debug and really fast. You could also detect code patterns more easily.

July 6th, 2012, 00:20	#28
-Ashe- Registered User Join Date: Oct 2011 Posts: 189	Yes but I don't want to use llvm, it's far more fun doing it yourself

July 6th, 2012, 05:31	#29
blueshogun96 Last Xbox Emu Author Join Date: Jun 2004 Location: Seattle, WA, USA Posts: 5,843	I recommend taking JayFox's advice, but suit yourself. __________________ Official Website of Shogun3D's RyuAwai! Shogun3D Game Development Blog Zengjük a Dalt: Manliest Song Ever!

July 6th, 2012, 06:11	#30
-Ashe- Registered User Join Date: Oct 2011 Posts: 189	I've worked on many compilers and recompilers in the past, and it's a hobby, so not sure why I'd use a library to do what I wanted to code this emulator for in the first place

July 6th, 2012, 13:42	#31
JayFoxRox Registered User Join Date: Dec 2010 Location: Germany Posts: 35	llvm could also only provide the optimization passes etc. which are VERY complex. It'd take years to implement only parts of those. For a project like this performance is critical, even if you don't want realtime emulation. llvm is not a drop-in PPC emulator either, so there is still plenty of work, very similar to normal interpreter development (Converting your high-level code to llvm code). But at the end of the day its obviously up to you. Good luck with your project anyway. Is there a repo already? Or do you have any screenshots?

July 6th, 2012, 19:35	#32
-Ashe- Registered User Join Date: Oct 2011 Posts: 189	It's not opensource, and I'm not sure a screenshot of a spinning triangle would be very useful

July 6th, 2012, 23:13	#34
-Ashe- Registered User Join Date: Oct 2011 Posts: 189	Yeah, I guess I just don't care enough about what people might think of my personal-boredom-killing-hobby But sure when I have something more interesting to show (maybe the least technically complex indie game displaying its main menu) I'll post it around here