Re: [PATCH] q800: implement mac rom reset function for BIOS-less mode

[Laurent Vivier]

Le 02/01/2020 à 11:36, Jason A. Donenfeld a écrit :
> On Linux, calling `reboot(RB_AUTOBOOT);` will result in
> arch/m68k/mac/misc.c's mac_reset function being called. That in turn
> looks at the rombase (or uses 0x40800000 is there's no rombase), adds
> 0xa, and jumps to that address. At the moment, there's nothing there, so
> the kernel just crashes when trying to reboot. So, this commit adds a
> very simple implementation at that location, which just writes to via2
> to power down.
> 
> Signed-off-by: Jason A. Donenfeld <address@hidden>
> ---

There are two cleaners solution to do that:
1- catch the jump to the ROM address in QEMU and shutdown the machine, see

https://github.com/vivier/qemu-m68k/commit/51cd57d1128059819038b9800455fbf794430c15

2- or as you do, write a fake ROM but use the VIA2 port B bit 3 to
shutdown the machine see hw/misc/mac_via.c mos6522_q800_via2_portB_write().

Thanks,
Laurent