[OpenBIOS] Haiku/ppc progress - ofmem_claim misbehavior?

[Mark Cave-Ayland]

Andreas Färber wrote:

> I've dropped the above patch in favor of a more readable ppc-only one:
> 
> diff --git a/arch/ppc/qemu/ofmem.c b/arch/ppc/qemu/ofmem.c
> index 7631a1c..2a5eca2 100644
> --- a/arch/ppc/qemu/ofmem.c
> +++ b/arch/ppc/qemu/ofmem.c
> @@ -431,4 +431,5 @@ ofmem_init( void )
> 
>      ofmem_map( 0, 0, get_ram_bottom(), 0 );
>      ofmem_map( get_ram_top(), get_ram_top(), ofmem->ramsize - 
> get_ram_top(), 0);
> +    ofmem_claim(get_ram_top(), ofmem->ramsize - get_ram_top(), 0);
>  }
> 
> ofmem_common.c:is_free considers 0x07f00000 free because it only sees 
> one range in ofmem->phys_range, 0x80000000 size 962560. Thus, I simply 
> claim the reserved part of RAM - no idea what side effects this may have...
> 
> On sparc64, instead of ofmem_map, opmem_map_page_range is called, but no 
> ofmem_claim either.

On SPARC64 I think ofmem_walk_boot_map/ofmem_map_page_range are used to 
set up the translations to cover the regions of memory used to hold 
OpenBIOS and beyond. According to the spec, a standard claim should NOT 
automatically generate a mapping IIRC as I had to fix this to get 
SPARC64 to boot further under OpenSolaris.

> Either way Haiku then hangs while trying to set the first segment 
> register (mtsrin):
> http://dev.haiku-os.org/browser/haiku/trunk/src/system/boot/platform/openfirmware/arch/ppc/mmu.cpp?rev=36886#L1005 

Interesting. It's great to see you making progress with this :)


ATB,

Mark.

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