Re: [PATCH v2 14/34] next-cube: add empty slots for unknown accesses to next.scr memory region

[Philippe Mathieu-Daudé]

On 12/12/24 12:46, Mark Cave-Ayland wrote:
> The next.scr memory is now effectively unused, however there are 3 separate 
> region
> accesses still logged that occur when booting a NeXTStep disk image. Use the
> empty_slot device to capture and ignore memory accesses to these 3 memory 
> regions.
>
> Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
> Reviewed-by: Thomas Huth <huth@tuxfamily.org>
> ---
>   hw/m68k/Kconfig     | 1 +
>   hw/m68k/next-cube.c | 8 ++++++++
>   2 files changed, 9 insertions(+)
>
> diff --git a/hw/m68k/Kconfig b/hw/m68k/Kconfig
> index 0092cda4e9..aff769b30f 100644
> --- a/hw/m68k/Kconfig
> +++ b/hw/m68k/Kconfig
> @@ -18,6 +18,7 @@ config NEXTCUBE
>       depends on M68K
>       select FRAMEBUFFER
>       select ESCC
> +    select EMPTY_SLOT
>   
>   config Q800
>       bool
> diff --git a/hw/m68k/next-cube.c b/hw/m68k/next-cube.c
> index 76ecf86ed0..95d01030cd 100644
> --- a/hw/m68k/next-cube.c
> +++ b/hw/m68k/next-cube.c
> @@ -22,6 +22,7 @@
>   #include "qom/object.h"
>   #include "hw/char/escc.h" /* ZILOG 8530 Serial Emulation */
>   #include "hw/block/fdc.h"
> +#include "hw/misc/empty_slot.h"
>   #include "hw/qdev-properties.h"
>   #include "qapi/error.h"
>   #include "qemu/error-report.h"
> @@ -1239,6 +1240,13 @@ static void next_cube_init(MachineState *machine)
>       /* BMAP IO - acts as a catch-all for now */
>       sysbus_mmio_map(SYS_BUS_DEVICE(pcdev), 1, 0x02100000);
>   
> +    /* unknown: Brightness control register? */
> +    empty_slot_init("next.unknown", 0x02110000, 0x10);
> +    /* unknown: Magneto-Optical drive controller? */
> +    empty_slot_init("next.unknown", 0x02112000, 0x10);
> +    /* unknown: Serial clock configuration register? */
> +    empty_slot_init("next.unknown", 0x02118004, 0x10);

IIRC the 'name' argument of empty_slot_init() was to log accesses,
but apparently the patch has never been merged.

Maybe use "next.unknown0/1/2" in preparation?

> +
>       /* BMAP memory */
>       memory_region_init_ram_flags_nomigrate(&m->bmapm1, NULL, "next.bmapmem",
>                                              64, RAM_SHARED, &error_fatal);