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Bytrix · Joined: 14 Sep 2005 Posts: 72 Location: England

I've seen two little samples that show how to use the ME to simply run a counter and display on screen, but I can't seem to find anything else that uses the ME at all.

My first question is, what does the ME do? (I know I can probably find out, but there's not a whole lot of documentation on it).

Secondly, I'm thinking the ME could be used to handle a second thread for a game (depending on what it's actually doing normally when the PSP is running). Say to process physics calculations. Does anyone know of any homebrew that uses the ME as a second thread processor? or have any example source code?

This isn't really essential, it's just I have no idea what this extra processor is doing there and if it's not doing much I might aswell try and use it.

hlide · Joined: 10 Sep 2006 Posts: 750

I'm working on it. It is not a very easy task because ME is not exactly an identical processor to the main one.

1) no VFPU on ME processor so I wouldn't consider any physics calculations on it.

2) no basic kernel functions, you just run plain kernel code so you need to handle everything, including the way to communicate between SC and ME processors. Access to file system for instance is probably beyond reach because there is no reason that all hardware registers are accessible from ME processor.

3) in fact a lot of things still need to be discovered. For example, no one seems how to use rpc calls or even how to signal the other processor an interrupt (it looks as if you need to run a setup code to enable the int 31 on ME processor which is not by default).

Bytrix · Joined: 14 Sep 2005 Posts: 72 Location: England

Thanks for the information, I had read a few other threads on the ME but they all seem to die and don't lead anywhere.

For now it's not important, but I'm interested in using it in someway, perhaps as some people have already mentioned it could be used to play the background music.

jonny · Joined: 22 Sep 2005 Posts: 351

there is a little lib in pmpmod source that can be used to take advantage of the ME.
you can basically run a function in the ME, wait for it to finish, check if its still running.
the "only" thing to take care is a correct cache handling to make everything works correctly.