On 12/12/2019 20:01, Laurent Vivier wrote: > MacOS reads this address to identify the hardware. > > This is a basic implementation returning the ID of Quadra 800. > > Details: > > http://mess.redump.net/mess/driver_info/mac_technical_notes > > "There are 3 ID schemes [...] > The third and most scalable is a machine ID register at 0x5ffffffc. > The top word must be 0xa55a to be valid. Then bits 15-11 are 0 for > consumer Macs, 1 for portables, 2 for high-end 68k, and 3 for high-end > PowerPC. Bit 10 is 1 if additional ID bits appear elsewhere (e.g. in VIA1). > The rest of the bits are a per-model identifier. > > Model Lower 16 bits of ID > ... > Quadra/Centris 610/650/800 0x2BAD" > > Signed-off-by: Laurent Vivier <laur...@vivier.eu> > --- > hw/m68k/q800.c | 22 ++++++++++++++++++++++ > 1 file changed, 22 insertions(+) > > diff --git a/hw/m68k/q800.c b/hw/m68k/q800.c > index 9ee0cb1141..c2b2aa779f 100644 > --- a/hw/m68k/q800.c > +++ b/hw/m68k/q800.c > @@ -97,6 +97,23 @@ static void main_cpu_reset(void *opaque) > cpu->env.pc = ldl_phys(cs->as, 4); > } > > +static uint64_t machine_id_read(void *opaque, hwaddr addr, unsigned size) > +{ > + return 0xa55a2bad; /* Quadra 800 ID */ > +} > + > +static void machine_id_write(void *opaque, hwaddr addr, uint64_t val, > + unsigned size) > +{ > +} > + > +static const MemoryRegionOps machine_id_ops = { > + .read = machine_id_read, > + .write = machine_id_write, > + .valid.min_access_size = 4, > + .valid.max_access_size = 4, > +};
Should there be a .endianness here just to be really safe? > static void q800_init(MachineState *machine) > { > M68kCPU *cpu = NULL; > @@ -110,6 +127,7 @@ static void q800_init(MachineState *machine) > MemoryRegion *rom; > MemoryRegion *ram; > MemoryRegion *io; > + MemoryRegion *machine_id; > const int io_slice_nb = (IO_SIZE / IO_SLICE) - 1; > int i; > ram_addr_t ram_size = machine->ram_size; > @@ -159,6 +177,10 @@ static void q800_init(MachineState *machine) > g_free(name); > } > > + machine_id = g_malloc(sizeof(*machine_id)); > + memory_region_init_io(machine_id, NULL, &machine_id_ops, NULL, "Machine > ID", 4); > + memory_region_add_subregion(get_system_memory(), 0x5ffffffc, machine_id); > + > /* djMEMC memory and interrupt controller */ > > djmemc_dev = qdev_create(NULL, TYPE_DJMEMC); Otherwise looks good and I see it being poked by a MacOS ROM so: Reviewed-by: Mark Cave-Ayland <mark.cave-ayl...@ilande.co.uk> ATB, Mark.