PCSX Development

**jivera** · October 16th, 2003

As I am sure you all know, Linuzappz posted about a month ago to PCSX.net that he's given up on maintaining the project in favour of being able to work on PCSX2. I contacted him via IRC and he approved of letting me work on the project.

Apparently he has also added two other programmers, yokota and imrtechnology, to the sourceforge.net account, but I haven't been able to get in contact with them yet.

I have recently uploaded the PCSX 1.6 development tarball into an arch archive (http://www.flame.org/~jivera/projects.html) and made the appropriate bug fixes for MinGW to compile. I have a few ideas I would like to get integrated into the code, but just noticed today that this bulletin board is still active and though I would first ask if anyone else has made efforts to reformalize the development process so our work doesn't need to be redundant.

Thank you,
-jivera

**zenogais** · October 17th, 2003

I've actually been looking over the source code, and if you wouldn't mind I would like to recommend a few improvements that you might make to PCSX. There are a few more optimizations that can be done to the recompiler to increase its speed even more, here's a list of possible ideas:

Caching of pre-compiled x86 code so that when loops are being processed the code doesn't have to be repeatedly regenerated.
You could also consider using circular buffers for loop-processing so that when a jump instruction is executed to previous code that has already been recompiled it will be immediately available in this recompiled form, this may take some r3000a binary analysis though.
Just a note, keeping track of these would require a 2D array that is written/read from based on the memory location of the translated instruction. This way you can check to see if you have already compiled the code at that location thus avoiding recompiling it again if it is not necessary.

These are just some thoughts from looking through the source code. Best of luck to you, and hope you make PCSX better than it already is.

-zenogais

**Xeven** · October 17th, 2003

Quote:

instruction is executed to previous code that has already been recompiled it will be immediately available in this recompiled form

that's one of the major precepts of binary translation or "recompilation" in the first place. Otherwise, you'd have to translate each "block" everytime it is accessed, which will make your "recompiler" much slower than the interpreter. So in short, it's already there.

**zenogais** · October 17th, 2003

Quote:

Originally Posted by Xeven

that's one of the major precepts of binary translation or "recompilation" in the first place. Otherwise, you'd have to translate each "block" everytime it is accessed, which will make your "recompiler" much slower than the interpreter. So in short, it's already there.

Sorry, Thanks Xeven.

I'm still a "newbie" for the most part to dynarec, thanks for the info.

**FLaRe85** · October 17th, 2003

I have a fairly simple suggestion. It'd be great to finally have some sort of command-line support in PCSX.

**jivera** · October 17th, 2003

ShADoWFLaRe85: I have a fairly simple suggestion. It'd be great to finally have some sort of command-line support in PCSX.

Can you be a little more specific with regard to what command-line options you would like to see? I believe I saw commented out code that would deal with command line stuff, but I haven't touched it yet.

Most of the features I'm interested in adding include better debugging (memory viewer, instruction stepper, breakpoints, etc.), but I'll try to add any requested features that are within my coding abilities.

zenogais, I took a look at your NeoPSX website and under progress research is listed as 100% -- what research have you done? I have found a document named "Everything You Have Always Wanted to Know about the Playstation But Were Afraid to Ask" and it does a good job at explaining the PSX, but leaves a lot out.

Possibly our projects can benefit from some cross pollination of code (for example, I can see if there are any PCSX-specific dependencies in the XA and mdec decoding routines that can be eliminated so they colud be used as library routines).

-jivera

**FLaRe85** · October 17th, 2003

Quote:

Originally Posted by jivera

Can you be a little more specific with regard to what command-line options you would like to see? I believe I saw commented out code that would deal with command line stuff, but I haven't touched it yet.

Sure. I think it'd be beneficial, especially for frontends, if you could perform basic launching options from the command-line that would otherwise only be accessible from the file menu. For example, 'pcsx.exe -loadbin c:\path\to\iso.bin' would auto-start an iso and 'pcsx.exe -runcd' would immediately launch the game in the CD-ROM drive at the time. I'm actually borrowing the syntax of those commands from ePSXe and PSXeven, respectively, but I'm sure you get the idea.

**jivera** · October 17th, 2003

ShADoWFLaRe85: Sure. I think it'd be beneficial, especially for frontends, if you could perform basic launching options from the command-line that would otherwise only be accessible from the file menu. For example, 'pcsx.exe -loadbin c:\path\to\iso.bin' would auto-start an iso and 'pcsx.exe -runcd' would immediately launch the game in the CD-ROM drive at the time. I'm actually borrowing the syntax of those commands from ePSXe and PSXeven, respectively, but I'm sure you get the idea.

Okay, those sound like fair requests. Right now I'm trying to find a way to profile the dynamic recompiler, but it so far seems I can only do that for the interpreter -- I probably need to figure out what special code gcc inserts when given the -pg flag so I can do the same inside the dynarec code.

I had to reinstall Windows a few weeks ago and lost all the plugins I had for PCSX. I downloaded some zip file with dozens of different plugins, but now cannot seem to find it (and not having a working joypad plugin kinda makes things difficult). If anyone knows where I can find that plugin collection again, I would appreciate it.

-jivera

**FLaRe85** · October 17th, 2003

Quote:

Originally Posted by jivera

ShADoWFLaRe85: Sure. I think it'd be beneficial, especially for frontends, if you could perform basic launching options from the command-line that would otherwise only be accessible from the file menu. For example, 'pcsx.exe -loadbin c:\path\to\iso.bin' would auto-start an iso and 'pcsx.exe -runcd' would immediately launch the game in the CD-ROM drive at the time. I'm actually borrowing the syntax of those commands from ePSXe and PSXeven, respectively, but I'm sure you get the idea.

Okay, those sound like fair requests. Right now I'm trying to find a way to profile the dynamic recompiler, but it so far seems I can only do that for the interpreter -- I probably need to figure out what special code gcc inserts when given the -pg flag so I can do the same inside the dynarec code.

I had to reinstall Windows a few weeks ago and lost all the plugins I had for PCSX. I downloaded some zip file with dozens of different plugins, but now cannot seem to find it (and not having a working joypad plugin kinda makes things difficult). If anyone knows where I can find that plugin collection again, I would appreciate it.

-jivera

Great

You could download Aldo's plugin pack at http://aldostools.mysite4now.com/psemu/plugins.zip

**jivera** · October 17th, 2003

Okay, I just wrote some (very fragile) proof of concept code and implemented the -runcd command line argument, so it shouldn't be difficult to write the rest of the code. Windows and Linux (or ANSI C rather) use different idioms for passing command line arguments (Windows has a single string, while Linux/ANSI C breaks the string at space boundaries).

When I get out of class and back to my appartment I will try to finish this code and possibly upload a build so people can test it out.

-jivera

Seta-San · October 17th, 2003

damned be the evil command line shadowflare. even bill can see it's dead.

Andrew Hruska · October 17th, 2003

Quote:

Originally Posted by Seta-San

damned be the evil command line shadowflare. even bill can see it's dead.

Oh, so you hate the CLI? DIE, DIE! Rot! hehe.

**FLaRe85** · October 17th, 2003

Quote:

Originally Posted by Seta-San

damned be the evil command line shadowflare. even bill can see it's dead.

You try writing a useful frontend-like application without a command line.

They're more helpful than they seem.

**zenogais** · October 18th, 2003

Quote:

Originally Posted by jivera

ShADoWFLaRe85: [b]
zenogais, I took a look at your NeoPSX website and under progress research is listed as 100% -- what research have you done? I have found a document named "Everything You Have Always Wanted to Know about the Playstation But Were Afraid to Ask" and it does a good job at explaining the PSX, but leaves a lot out.

Possibly our projects can benefit from some cross pollination of code (for example, I can see if there are any PCSX-specific dependencies in the XA and mdec decoding routines that can be eliminated so they colud be used as library routines).

-jivera

I'd be glad to help out PCSX.

I wouldn't say I'm exactly the best person to talk to, but I'll answer what I can. As for the research, most of my research has been through reading PSX Hardware docs, looking through some source code, looking at some PSX binaries, and thats about it. Here's a few docs, besides the one you listed, I read just to help me out with programming an emulator as well as Playstation specific stuff:

1964 Recompiling Engine Doc

Aemulor Recompiler Docs

Padua Playstation Resource

PSX Hardware Docs

R3000A Hardware Docs

Also right now for NeoPSX I'm working on the dynarec, I have about half the PSX instructions coded, and I'm also working on doing optimizations with this code such as some of the ones I mentioned earlier. Hope this helps, just email me if you have any more questions/comments.

Sincerely,
zenogais

M.I.K.e7 · October 18th, 2003

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