Roman Zippel wrote: > Hi, > > On Mon, 26 Feb 2007, Wouter Verhelst wrote: > >>> It's probably not impossible, but I highly question whether it's really >>> desirable. The instructions sets are already quite different >> This is not true. The ColdFire V4e instruction set is a near-strict >> subset of the m68k one. The only instruction in the core set that does >> not yet exist on classic m68k is FF1, for "find first one" in a >> bitfield; and as far as I can see, the only cases where the ColdFire >> behaves significantly different from classic m68k are in FMOVEM (which >> can be worked around by allocating two more bytes per copied register >> than would be necessary on ColdFire) and when addressing using address >> register postincrement or predecrement mode on A7 in byte context (which >> can be rather easily avoided). >> >> There are of course things like the EMAC and the likes, but those are >> not part of the core ColdFire V4e instruction set, and there exist >> indeed CF V4e CPUs that don't support it. > > Linux doesn't just use the classic m68k instructions, it always required > at least a 68020, so this had to go (this means e.g. less addressing > modes and no bitfield instructions).
BTW, it's the reason why we cant' use qemu-m68k to create virtual m68k build machine : qemu supports only coldfire and thus is not able to run 68020 objects. Regards, Laurent -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
