Re: [Qemu-devel] can't boot debian wheezy sparc in qemu

[Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>]

On 17/07/14 07:43, Dennis Luehring wrote:

> Am 16.07.2014 00:21, schrieb Mark Cave-Ayland:
>> At the moment my work is focused on getting the basic system emulation
>> up and running, so I haven't spent much time looking at the graphics
>> side at all.
>>
>> I have noticed that the kernel falls back to the dummy console during
>> boot, so perhaps it is unable to probe the VGA device. If you append
>> vga=ask to the command line, are you able to find a framebuffer choice
>> that works?
>
> the vga=ask parameter is x86 only
>
> https://lists.debian.org/debian-user/2014/07/msg00872.html

Really? That's a shame. The problem I'm looking into at the moment is 
related to incorrect BAR ranges properties for the ebus and VGA which 
means that the properties in the device tree don't always match up.

Fortunately Linux tends to probe/configure everything itself which is 
why it boots; the BSDs start parsing various BAR properties to find out 
what resources have been assigned by OpenBIOS and then fall over when 
the properties don't quite line up with how the BARs are programmed. It 
could be that maybe the difference is also causing the VGA probe to fail?

If any of the Debian people are interested in helping and have a debug 
kernel available, I'm sure it wouldn't take someone who has basic SPARC 
Linux kernel knowledge too figure out what's happening (and even better 
you can boot the kernel directly in QEMU with the -kernel parameter 
rather than having to keep building a custom image).


ATB,

Mark.