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Old 05-24-2012, 09:31 PM   #9
liteon
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Quote:
Originally Posted by Justin View Post
Very cool! I'm about to push some new EEL changes online, including a bytecode interpreted mode (that is portable)... Now I'm tempted to go find a Raspberry Pi to help port the native ARM version (with FPU I hope?). Sorry if all of our EEL changes cause merge hell :/
no problem,
there isn't much of a trouble merging, really...

the CPU in Raspberry PI is a bit outdated - ARM1176JZF-S, but has a VFP unit and is good enough for development. i wanted to get soft-float support in, because unlike the x87, which will probably be there for quite some time, ARM might soon decide to deprecate the VFP unit at some point to save dye space (and thus force use of the newer NEON SIMD only or come up with something else). there are a lot of ARM CPU's that have different floating logic and are simply not compatible (VFP,NEON,FPA,FPE).

if we neglect that, the VFP control word has a field that puts the co-processor into scalar mode which is suitable for EEL2, i think.
https://www.scss.tcd.ie/~waldroj/3d1/arm_arm.pdf
page 885.

the register exchange (CPU-COP) and overall the instruction sets are pretty straightforward.

i wouldn't consider working on a mobile device, unless its possible to attach a real monitor, mouse and a keyboard to it. also, i don't think serious programmers can be convinced that Android or iOS are better than something like Debian for development.

for the sake of running on a mobile device i did run a previous build of EEL2 on an Android phone, but then the build broke at some point. :\

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