19 Mar
2012
19 Mar
'12
2:56 p.m.
David Riley wrote:
Unfortunately, that method of trapping A-line
instructions makes it
impossible to try to port MacOS to Coldfire (something which I had
the harebrained idea to do once), because Coldfire uses the 0xA
prefix for its enhanced MAC (multiply-accumulate, not Mac, though
the irony is delicious) unit. You'd have to do other opcode
translations, too, but that pretty much blows the Toolbox calls out
of the water, since there's no equivalent illegal prefix.
So what? Since
you're going to have to reassemble/recompile code
anyhow, just do the system calls with two words instead of one. If you
felt strongly about it, the second word could even be the exact Axxx
word used on the Mac.