PSP Homebrew. How well does it work?

ZMaster · Post by **ZMaster** » Fri Sep 02, 2005 10:21 pm

Hi,

I'm interested in doing some PSP stuff. I don't own a PSP right now, but I would need to buy the European one, since it was released yesterday and now it's hard to get your hands on an imported one.

How well ist the PSP coding working, yet?
I saw the PSPSDK has an OpenGL implementation and by looking into the gl.h header, I must say that it's pretty complete. How much of the functions that are listed in the Header file are really working?

Does loading textures work? I read something here, a few weeks ago, that you actually can't load textures or it's very complicated.

At least I would also like to know what you need to get homebrew code running on your PSP. Does it require some swapping exploit or is it just uploading your compiled program and run it? What about debugging? Is there a comfortable way to debug your applications?

Thanks,
ZMaster

Matrixdub · Post by **Matrixdub** » Fri Sep 02, 2005 11:01 pm

You cannot run homebrew on the European PSP as yet...

The closest way would be to wait for Yoshihiro's downgrade from 1.5x to 1.5...

That is if you ignore the "Warning" on the European PSP box and don't upgrade to the 2.0 that is on the freebie UMD!

Arwin · Post by **Arwin** » Sat Sep 03, 2005 12:03 am

Ordering one from Japan might still get you a 1.50 PSP, but it'll be getting harder. Alternatively, you can try tracking down a 1.50 PSP on ebay.

Or, of course, be patient and see if someone figures out how to run Homebrew on 1.52 or better yet, 2.0.

ZMaster · Post by **ZMaster** » Sat Sep 03, 2005 12:21 am

Arwin wrote:Ordering one from Japan might still get you a 1.50 PSP, but it'll be getting harder. Alternatively, you can try tracking down a 1.50 PSP on ebay.

Or, of course, be patient and see if someone figures out how to run Homebrew on 1.52 or better yet, 2.0.

I think newer firmware versions are not just released to prevent people from running homebrew software, but might also fix serious bugs or install addons that might be required by future games, so that someday one might have to upgrade to run newer games. If you ask me, I find it stupid that Sony is always trying to keep homebrew coders away.

I read somewhere, that Sony is planing to release a new firmware version, that allows BASIC games to be downloaded from the internet and run on the PSP. With basic they probably mean no access to the hardware 3D acceleration and no WIFI support (or similiar) but if such a firmware will be released there might be a change to get games writting with the PSPSDK running without major hacking efforts?!?

What about my other questions? OpenGL and Texture support? Anyone knowing about these?

mofig · Post by **mofig** » Sat Sep 03, 2005 4:28 am

yes, the opengl actually works quite well, and if you already know opengl it is quite easy to use. At the moment textures also work, however I believe you have to load them as raw files in a specific format... the most i've done with textures so far is replacing the one thats used in the cube sample. i'm not sure if the libjpg or libpng libraries actually work at the moment.

holger · Post by **holger** » Sat Sep 03, 2005 5:55 am

Right now textures, vertex and index arrays need to get provided in native hardware formats and aligned to 16-byte boundaries. Some generic code doing the conversion on-the-fly if required has been written by Jeremy, the patches are available on his website but not yet completely incorporated. See the pspgl/ directory for a list of implemented functions. Most are quite easy to understand, take a look in the source to see what's done and what's still missing.

In general we only implemented things that the PSP can do in hardware, no software fallbacks (you don't want to use them anyways in most cases, so better realize soon that it's not supported by the hardware). The skinning and matrix/vertex blend extensions are not yet done, also are the Bezier Evaluators still missing. Well-done patches are welcome.

glReadPixels/CopyPixels/DrawPixels() are missing too, but somebody promised to work on this, don't know the current status, though. See the Q3 thread in this forum for details.

ZMaster · Post by **ZMaster** » Sat Sep 03, 2005 6:32 am

Thank you.

Except for the 16-bit alignment, how standard conform are the pspgl functions?
I do both, OpenGL programming for the PC and Sega's Dreamcast and I can say that the gl implemention of the KallistiOS for DC is in a lot of ways behaving very different from what you'd expect from the "original" OpenGL.

holger · Post by **holger** » Sat Sep 03, 2005 6:57 am

well... look on the file dates and extrapolate how conformant an implementation as young as this one may be ;-)

no, seriously: Most of the parts we implemented should (if there are no hidden bugs) behave as expected. Nevertheless you need (as you always should do if you want to get performant results on embedded platforms) to care about some special "features" of the PSP. It's a pretty cool graphics engine, but by no means designed for the desktop. I updated the README to list the issues one should keep in mind when coding for the PSP, this list is by no means complete, please let me know if you encounter new issues.

Pleaase let us know when you discover some unexpected behaviour: right now the probability that you found a bug is pretty high.

ZMaster · Post by **ZMaster** » Sat Sep 03, 2005 7:13 am

holger wrote:Nevertheless you need (as you always should do if you want to get performant results on embedded platforms) to care about some special "features" of the PSP. It's a pretty cool graphics engine, but by no means designed for the desktop.

Thx. Yeah, I'm definitelly aware of this.

I really appreciate the progress of the PSPSDK if you consider that the system is out only since a few months. The SDK seems quite complete to me and that there may be bugs in a software that is so heavy under development is just a natural thing...

I just needed to know because I seriously consider buying one of those neat black devices and I usually enjoy coding games even more than I do playing them :-)