On Fri, 8 Apr 2022, Rob Landley wrote: > On 4/5/22 08:07, Greg Ungerer wrote: > > On 5/4/22 13:23, Daniel Palmer wrote: > >> On Mon, 4 Apr 2022 at 22:42, Greg Ungerer <gerg@xxxxxxxxxxxxxx> wrote: > >>> But we could consider the Dragonball support for removal. I keep it > >>> compiling, but I don't use it and can't test that it actually works. > >>> Not sure that it has been used for a very long time now. And I > >>> didn't even realize but its serial driver (68328serial.c) was > >>> removed in 2015. No one seems too have noticed and complained. > >> > >> I noticed this and I am working on fixing it up for a new Dragonball > >> homebrew machine. I'm trying to add a 68000 machine to QEMU to make > >> the development easier because I'm currently waiting an hour or more > >> for a kernel to load over serial. It might be a few months. > > I've been booting Linux on qemu-system-m68k -M q800 for a couple years > now? (The CROSS=m68k target of mkroot in toybox?) > > # cat /proc/cpuinfo > CPU: 68040 > MMU: 68040 > FPU: 68040 > Clocking: 1261.9MHz > BogoMips: 841.31 > Calibration: 4206592 loops > > It certainly THINKS it's got m68000... > Most 68040 processor variants have a built-in MMU and the m68k "nommu" Linux port doesn't support them. The nommu port covers processors like 68000, Dragonball etc. whereas the m68k "mmu" port covers 680x0 where x is one of 2,3,4,6 with MMU. > $ qemu-system-m68k -cpu ? > cfv4e > m5206 > m5208 > m68000 > m68010 > m68020 > m68030 > m68040 > m68060 > any > > (I'd love to get an m68k nommu system working but never sat down and > worked out a kernel .config qemu agreed to run, plus compiler and libc. > Musl added m68k support but I dunno if that includes coldfire?) > I could never figure out how to boot a coldfire machine in qemu either. There was no documentation about that back when I attempted it but maybe things have improved since. > >> It looked like 68328serial.c was removed because someone tried to > >> clean it up and it was decided that no one was using it and it was > >> best to delete it. My plan was to at some point send a series to fix > >> up the issues with the Dragonball support, revert removing the serial > >> driver and adding the patch that cleaned it up. > > > > Nice. I will leave all the 68000/68328 code alone for now then. > > The q800 config uses CONFIG_SERIAL_PMACZILOG. Seems to work fine? > That driver would work on certain 68000 systems e.g. early Macs. (And IIRC someone did once boot a customized Linux kernel on a Mac SE...)
