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Re: [PATCH 3/3] q800: add machine id register
From: |
Mark Cave-Ayland |
Subject: |
Re: [PATCH 3/3] q800: add machine id register |
Date: |
Sat, 14 Dec 2019 10:55:54 +0000 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.2 |
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 <address@hidden>
> ---
> 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 <address@hidden>
ATB,
Mark.