Re: framebuffer console on old ATI

[Michael <macallan1888%gmail.com@localhost>]

Hello,

On Thu, 23 May 2024 09:11:17 +0000
Riccardo Mottola <riccardo.mottola%libero.it@localhost> wrote:

> Michael wrote:
> > Did it crash or did if continue booting? If it continued to boot
> > radeonfb likely got the wiring of outputs to displays wrong.
> > With that, please try with options RADEONFB_BIOS_INIT, which adds code
> > to scan the BIOS for output info. This is not enabled by default
> > because most hardware we run radeonfb on doesn't have a PC BIOS. Should
> > probably be on by default on x86.  
> 
> did so. Still get a black screen. Before going black, I am able to see a
> "failed".
> Also, it hangs, because if I wait some time I can't login remotely (left
> dhcp&telnet on).

This is odd, but it's a data point at least.
Does it hang without RADEONFB_BIOS_INIT as well?
If it doesn't and you just get no useful output - does the laptop in
question have a VGA or DVI output? If it does, could you plug something
into it?
The reason I'm asking is, most/maybe all radeons have at least two
outputs, how they're wired to connectors, LCDs etc. is up to the
vendors. Normally there is a table in the video BIOS telling us exactly
what is connected to what. That's what RADEONFB_BIOS_INIT tries to find.
If we get it wrong we may very well end up with a black display.
On macppc we don't have a connector table but pretty much all *Books
wire up the internal display in exactly the same way, there are a few
exceptions but we can distinguish those from the model string in OF.

I know RADEONFB_BIOS_INIT works on macppc because I have an r360 card
with both OF and a PC BIOS in ROM, and with it radeonfb correctly
identifies both outputs as DVI.

The other possible cause would be some endianness screwup, radeonfb has
been used mostly on macppc and sparc64, and not much else. IIRC some
brave soul made it work on alpha a while ago, but it got pretty much
zero testing on x86.

> thanks to easy videos with iPhones... I was able to extract a frame:
> 
> radeonfb0: BIOS initialization failed

So the machine probably doesn't have a video BIOS, just like most Apple *Books.

Does Xorg run with a radeon driver on any OS at all? If so, could you
send me the xorg.0.log from such a thing? That should give at least a
hint on what we get wrong.

have fun
Michael