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...)
