java on psp

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kjeevah
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Joined: Thu Mar 31, 2005 5:52 am

java on psp

Post by kjeevah »

hi

i dont really know what im talking about so feel free to flame me if its all a load of arse but anyway..

you can now use a web browser via wipeout pure, right? in that case - can it run java applications? the implications are obvious!

even if it isn't possible, once code can actually be run off the memory stick, would sticking some kind of a java virtual machine on there shortcut having to write alot of emulators?

cheers!

kj

p.s. i cant actually try and find out for myself as im waiting for a proper psp homebrew breakthrough before i bin my gba+flashcart+quirky-CHAOS-remake!
pdc
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Post by pdc »

No it does not support Java.
The implications are indeed obvious :P

Having "some kind of Java VM" isn't really an option for the Wipeout/PSP browser, as no one really knows what the browser is - never mind how to integrate some sort of Java VM.

The best bet would be to port a Mozilla browser and a compatible Sun Java VM.
I must say I'm not sure how portable the Java VM is though. Isn't it closed-source?
mharris
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Joined: Sun Jan 25, 2004 2:26 pm
Location: Annapolis, MD, USA

Post by mharris »

pdc wrote:I must say I'm not sure how portable the Java VM is though. Isn't it closed-source?
There are numerous open- and semi-open-source Java VMs. The source for Sun's HotSpot VM is one of the better-supported ones (it falls into the semi-open-source category). This is the VM that you get when you get Java from Sun for the x86 (Windows/Linux/Solaris) and Sparc. Apple has ported it to PPC/OSX -- it's the Java VM that's part of OSX -- but as far as I can tell, they haven't made their source available, which is acceptable under Sun's license.

Porting HotSpot to MIPS/PS2 would be a huge undertaking -- I know, because I tried once ;-) My big problem, which I was unable to resolve, was to separate the VM runtime environment from the JIT stuff. The JIT compiler requires all kinds of definitions about the underlying architecture (registers, stack layout, etc.); although this is not rocket science, it's a lot of grunt work, which I didn't have the stamina to deal with after a while. It would be nice to have just the VM always run in "bytecode-interpretation" mode (i.e., no JIT), even though it would be sluggish... IIRC, this is the way all of the JDK 1.2 and earlier VMs worked. I couldn't find a way to get HotSpot to build in this restricted way, so I gave up :-/

There are other open source JVMs out there -- Kaffe is the one I'm most familiar with, but it hasn't been updated since Feb 2004. There's supposedly a PS2 port for it here, but it's all in Japanese, so I have no idea how complete it is. From what little I can glean from the romanji, it only works on the Linux kit anyhow.

Doubtless there are other open-source VMs out there in various states of usability.
mrbrown
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Post by mrbrown »

Moved to the PSP General Discussion.
"He was warned..."
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