Coldfire status

[Doobrey]

motorollin wrote:
 Looks like there are some essential missing instructions in the Coldfire CPU which means 68k compatibility won't be possible without emulation (=UAE) :-(

Not necessarily.
If the missing instructions can be caught with the illegal instruction trap then only those instructions will have to be emulated (just like the 040/060 libs do for the missing FPU instructions)
 The real bugger will be if there's any instructions that aren't 100% identical in use to the 68k versions.

[Doobrey]

jdiffend wrote:

There are ways around all the software problems, but to do this would require a new Amiga exec.library since it executes illegal (on the coldfire) instructions early in the startup code.  It's so early that it crashes before it could even transfer to an expansion ROM (actually, it happens *while* it's checking for one).

I was gonna jump in and say something like ' Easy, override the ROM on a reset with one that inits the coldfire and then go back to the standard kickstart once the traps are setup'

But then the coldstart in exec resets all traps/exceptions to the ones in ROM. So that's the simple trap method up the creek  :-x

I thought Piru was mad for suggesting a full 68k emulation, but now I see the light.

If someone had access to the Amiga ROM sources this wouldn't be a bad project.  Without that you have to reverse engineer things, fix them, etc...

Pffff.. having the sources takes all the fun out of it :crazy:

[Doobrey]

Piru wrote:
Checksums would also be a problem (just try running xvs.library or elbox drivers when the code has been modified, for example).

 :lol:

[Doobrey]

@motorollin,
 'Cos it'd mean trying to make a deal with Amiga Inc to get a license and the sources?(IIRC, they don't have the sources to 3.5+3.9 so patching that could be another problem)