Re: [Qemu-devel] MMIO address changes

[Paul Brook <paul@codesourcery.com>]

> diff --git a/exec.c b/exec.c
> --- a/exec.c
> +++ b/exec.c
> @@ -2295,6 +2295,7 @@ void
> cpu_register_physical_memory_offset(target_phys_addr_ t start_addr,
>                  p->region_offset = 0;
>              } else {
>                  p->phys_offset = phys_offset;
> +                p->region_offset = region_offset;
>                  if ((phys_offset & ~TARGET_PAGE_MASK) <= IO_MEM_ROM ||
>                      (phys_offset & IO_MEM_ROMD))
>                      phys_offset += TARGET_PAGE_SIZE;

I guess this makes sense, however..

> You can see the difference when you register a region overriding
>  other(perhaps bigger) region.
>
> hw/sh7750.c hits this by registering
>  0xfc000000 .. 0xffffffff for CPU control registers,
> then
>  0xffe00000 .. 0xffe00028
>  0xffe80000 .. 0xffe80028
>  0xffd00000 .. 0xffd01000
>  0xffd80000 .. 0xffd81000
>  ...

You should not rely on overlapping regions doing anything sensible.

Paul