[OpenBIOS] [sparc64] Problematic pci at 0 and pci nodes in the device tree

Jakub Jermar jakub at jermar.eu
Sun Jan 18 19:23:54 CET 2009

Blue Swirl wrote:
> On 1/18/09, Jakub Jermar <jakub at jermar.eu> wrote:
>> Blue Swirl wrote:
>>  > On 1/16/09, Jakub Jermar <jakub at jermar.eu> wrote:
>>  >> Hi,
>>  >>
>>  >>  I have the following problem with the OpenBIOS device tree (the current Qemu version):
>>  >>  In the root directory, there are currently two pci nodes:
>>  >>
>>  >>  ffd97778 pci at 0
>>  >>  ffd98808 pci
>>  >>
>>  >>  The "screen" alias is defined as:
>>  >>  /pci/pci/pci/QEMU,VGA
>>  >>
>>  >>  When HelenOS attempts to lookup this path, it fails, because it matches /pci instead
>>  >>  of /pci at 0 and /pci does not have any children. HelenOS is normally designed to cope
>>  >>  with ambiguous node names, but in this case the /pci node matches and sends it to the
>>  >>  wrong direction. I think the "screen" alias should be either defined using the
>>  >>  non-ambiguous pci at 0 path components or the /pci node should not exist at all.
>>  >>
>>  >>  Can you confirm this is a problem in the tree?
>>  >
>>  > Yes, there is a duplicate for some reason for most PCI devices. Also
>>  > the address is 0, except for IDE and serial.
>> After some recent changes in Qemu, this is no longer a problem and HelenOS finds
>>  the QEMU,VGA node.
>>  The properties needed to find the physical address of the framebuffer seem to
>>  be still wrong. Is this fixed in the upstream version of OpenBIOS (I still haven't
>>  figured out how to build openbios :-()? Basically what is needed is the reg property
> First, you need binutils and gcc. For cross compiling I'd recommend
> sparc64-elf target, then you avoid a lot of unneeded Linux
> headers/libgcc stuff. At least binutils 2.18 and gcc 4.2.4 build
> working binaries.

Ok, I will try sparc64-elf.

> I still don't have a working cross gdb for Sparc64,
> the obvious configuration (--target=sparc64-elf) doesn't work.

What exactly is the problem, maybe I can help???
I built cross-gdb for sparc64-linux-gnu. On another computer,
I had some problems with newer versions of gcc, so I built
using gcc-3.4.

>>  in the screen node and ranges properties in all the nodes above screen up to the
>>  root. I believe the address property is normally used to hold a virtual address
>>  valid for ofw-managed mappings (not the physical address), but I may be wrong.
> Ok, I'll check.



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