John Paul Adrian Glaubitz wrote: [...] > How much are these instruction set compatible with the classical m68k > processors? Would we be able to have an m68k port of Debian which runs > both on the original m68k CPUs and the ColdFire series? AFAIK the ColdFire is nearly, but not quite, a strict subset of the m68k. There appear to be a fairly small number of instructions which behave differently. See here: http://www.microapl.co.uk/Porting/ColdFire/cf_68k_diffs.html Supervisor mode is quite different but that won't affect user mode applications (i.e. stuff that Debian is interested in). So at first glance it looks like it would be possible to generate ColdFire code which would also run on a 68k. The compiler would have to be careful not to rely on behaviour which was different on the two processors. A quick glance at the gcc options doesn't show any obvious flags to do this, unless -march=isaa -mtune=68000 works. Incidentally, microapl do make a (sadly commercial) product which allows you to run 68k code on a ColdFire, which works by trapping unimplemented instructions in software. It's pitifully slow by all accounts but it does seem to work. -- ┌─── ｄｇ＠ｃｏｗｌａｒｋ．ｃｏｍ ───── http://www.cowlark.com ───── │ "There is nothing in the world so dangerous --- and I mean *nothing* │ --- as a children's story that happens to be true." --- Master Li Kao, │ _The Bridge of Birds_
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