Re: [OpenBIOS] Booting SunOS from OpenBIOS

[Mark Cave-Ayland]

On 02/04/13 20:12, Artyom Tarasenko wrote:
> After some debugging, I think the problem is in the current
> obp_memalloc realization: it calls ofmem_claim_virt which
> expects the address to be precise and thus can not be called
> twice for the same virtual address.
>
> Looking at the OpenSolaris headers (
> http://fxr.watson.org/fxr/source/sun/sys/promif.h?v=OPENSOLARIS#L83 )
>
> extern  caddr_t         prom_alloc(caddr_t virthint, size_t size, uint_t align);
>
> it seems that "virthint" is just a hint for a virtual address, so
> prom_alloc (which is our obp_memalloc) shall not fail unless the whole
> RAM is exhausted.
> The comment on lines 70-71 says:
>
> "The alloc function should guarantee that it will never return an
> invalid pointer."
>
> Someone cares to fix?

Ah I think I may see the bug here - what if you change 
arch/sparc32/lib.c line 276 in obp_memalloc() from:

virt = ofmem_claim_virt(pointer2cell(va), size, 0);

to:

virt = ofmem_claim_virt(pointer2cell(va), size, align);

Does that fix the bug for you?

ATB,

Mark.

Booting SunOS from OpenBIOS

[Artyom Tarasenko]

On Tue, Apr 2, 2013 at 9:45 PM, Mark Cave-Ayland
 wrote:
> On 02/04/13 20:12, Artyom Tarasenko wrote:
> > After some debugging, I think the problem is in the current
> > obp_memalloc realization: it calls ofmem_claim_virt which
> > expects the address to be precise and thus can not be called
> > twice for the same virtual address.
> >
> > Looking at the OpenSolaris headers (
> > http://fxr.watson.org/fxr/source/sun/sys/promif.h?v=OPENSOLARIS#L83 )
> >
> > extern  caddr_t         prom_alloc(caddr_t virthint, size_t size, uint_t
> > align);
> >
> > it seems that "virthint" is just a hint for a virtual address, so
> > prom_alloc (which is our obp_memalloc) shall not fail unless the whole
> > RAM is exhausted.
> > The comment on lines 70-71 says:
> >
> > "The alloc function should guarantee that it will never return an
> > invalid pointer."
> >
> > Someone cares to fix?
>
> Ah I think I may see the bug here - what if you change arch/sparc32/lib.c
> line 276 in obp_memalloc() from:
>
> virt = ofmem_claim_virt(pointer2cell(va), size, 0);
>
> to:
>
> virt = ofmem_claim_virt(pointer2cell(va), size, align);
>
> Does that fix the bug for you?

At least, it seems to die some instructions later, thanks! Will debug more.
Does it mean that obp_memalloc is actually using the first argument
just as a hint? As the OpenSolaris header suggests?

Artyom

linux/sparc and solaris/sparc under qemu blog:
http://tyom.blogspot.com/search/label/qemu