[OpenBIOS] Haiku/ppc progress - ofmem_claim misbehavior?

[Andreas Färber]

Am 24.05.2010 um 17:21 schrieb Artyom Tarasenko:

> 2010/5/24 Andreas Färber <andreas.faerber at web.de>:
>> Am 24.05.2010 um 16:22 schrieb Stefan Reinauer:
>>
>>> On 5/24/10 4:18 PM, Andreas Färber wrote:
>>>>
>>>> +        phys = ofmem_claim_phys_( addr, size, align, 0,
>>>> get_ram_size() - 0x00100000 - (2 << 15) - (32 + 32 + 64) * 1024,  
>>>> 1 /*
>>>> reverse */ );
>>>> +        virt = ofmem_claim_virt_( addr, size, align, 0,
>>>> get_ram_size() - 0x00100000 - (2 << 15) - (32 + 32 + 64) * 1024,  
>>>> 1 /*
>>>> reverse */ );
>>
>> The question is, why does claim overwrite the 0x07ed0000 identity  
>> map of
>> length 1245184, that I see no in my debug output now, with a  
>> 0x07f00000 map
>> when using the vanilla OpenBIOS code?
>> And do we need to supply platform-specific functions  
>> arch_get_ram_top and
>> arch_get_ram_bottom, or is my approach just working around the  
>> problem?
>
> Not sure if it's a platform-specific problem: on sparc32 with a  
> similar patch
> Solaris boot gets a bit further.

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.

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

Andreas