On Mon, 2020-04-27 at 17:52 +0200, Karoly Balogh (Charlie/SGR) wrote: > Hi, > > On Mon, 27 Apr 2020, Sven Barth via fpc-devel wrote: > > >> Well, I'm surprised and impressed you got it to work at all... > >> Quite an achievement. > > > > Considering that we already support AVR as well I was rather > confident > > here. :D Maybe in the future we can also add GameBoy support which > uses > > some Z80/8080 hybrid? ^^' > > I have no idea, but quickly read through some docs, and it seems the > GameBoy CPU doesn't have IX/IY registers, which seems to be very > useful to > implement some of the more complex references handling, according to > what > Nikolay wrote earlier. Also, it seems to be quite a few stuff missing > from > it, as well as it has some extras. The question is, how far it > diverges > from Z80 of course, and how that might violate some basic assumptions > the > Z80 CG currently does about the ISA.
Ah, that sucks :( We currently use IX as the frame pointer (similar to BP on i8086), and there's this very convenient (IX+d) addressing. SDCC does the same. So, this would mean the GameBoy would probably be a different architecture, as far as FPC is concerned, with possibly some shared units, like maybe the instruction set info tables, etc. It think SDCC also treats it as a different arch. Nikolay _______________________________________________ fpc-devel maillist - fpc-devel@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-devel
