Re: [MiNT] MiNTLib for ColdFire : DONE !

[Peter Persson <pep.fishmoose@gmail.com>]

Hi,

Ok, tricky. MVS and MVZ could be trapped and emulated, but the MAC  
instructions screw things up.. Didier solved the latter by using an  
unused TRAP instruction. Is this something which could be added to the  
kernel as well? It does make it slightly easier to write code for both  
systems, since I woudn't have to check which CPU I'm running on.

-- PeP

4 jun 2009 kl. 16.21 skrev Vincent Rivière:

> No. The ColdFire lacks a lot of the 680x0 instructions and address  
> modes, but it also adds a few new instructions. See at the bottom of  
> this page:
> http://www.microapl.co.uk/Porting/ColdFire/cf_68k_diffs.html
>
> For example, there is no add.b and add.w on ColdFire. The data must  
> be fetched into a register, then add.l can be used. The new mvs and  
> mvz instructions can be used to fetch a byte or a word, then fill  
> the remaining part of the target register to be suitable for add.l.
>
> Some examples here (in French):
> http://coldfire.zewan.com/68k_cf.htm
>
> GCC uses a lot these new instructions, as well as 68020 instructions  
> compatible with ColdFire, so without a CPU check ColdFire binaries  
> crashes on 68000 and 68020.
>
> --
> Vincent Rivière