Re: [Qemu-devel] uvesafb doesn't work with seabios

[Kevin O'Connor <kevin@koconnor.net>]

On Fri, May 09, 2014 at 05:06:21PM +0200, Bernhard Walle wrote:
> Hello,
> 
> I'm using QEmu 2.0.0 on a Linux host (x86-64) with a quite special
> target system that uses uvesafb ('video=uvesafb:1024x768-32'). I get
> following errors in the target system:
> 
>     uvesafb: Getting mode info block for mode 0x2 failed (eax=0x4f01, err=1)
>     uvesafb: Getting mode info block for mode 0x3 failed (eax=0x4f01, err=1)
>     uvesafb: Getting mode info block for mode 0x4 failed (eax=0x4f01, err=1)
>     uvesafb: Getting mode info block for mode 0x5 failed (eax=0x4f01, err=1)
>     uvesafb: Getting mode info block for mode 0x6 failed (eax=0x4f01, err=1)
>     uvesafb: Getting mode info block for mode 0x7 failed (eax=0x4f01, err=1)
>     uvesafb: Getting mode info block for mode 0xd failed (eax=0x4f01, err=1)
>     uvesafb: Getting mode info block for mode 0xe failed (eax=0x4f01, err=1)
>     uvesafb: Getting mode info block for mode 0xf failed (eax=0x4f01, err=1)
>     uvesafb: Getting mode info block for mode 0x10 failed (eax=0x4f01, err=1)
>     uvesafb: Getting mode info block for mode 0x11 failed (eax=0x4f01, err=1)
>     uvesafb: Getting mode info block for mode 0x12 failed (eax=0x4f01, err=1)
>     uvesafb: Getting mode info block for mode 0x13 failed (eax=0x4f01, err=1)
>     uvesafb: Getting mode info block for mode 0x6a failed (eax=0x4f01, err=1)
>     uvesafb: vbe_init() failed with -22
>     uvesafb: probe of uvesafb.0 failed with error -22
> 
> With QEmu 1.6, it worked. I bisected that down to following commit:
> 
>     commit 6eefccc0bb9c34051b1e21880fc3a1c1c8686edd
>     Author: Gerd Hoffmann <kraxel@redhat.com>
>     Date:   Mon Dec 2 13:01:20 2013 +0100
> 
>     roms: update vgabios binaries
> 
> And indeed, when I switch 'vgabios-stdvga.bin' to the old variant, it works.
> 
> What can I do to track down the problem? I tried to build the svga bios
> inside the QEMU tree, but I didn't succeed. Building it in the current
> seabios git tree worked, but I got a different error...

Can you run the original SeaVGABIOS image and provide the output with
the following added to the qemu command line:

-chardev stdio,id=seabios -device isa-debugcon,iobase=0x402,chardev=seabios

Also, it looks like uvesafb can call x86emu.  Older versions of x86emu
are known to not emulate some instructions properly, and it has caused
problems for SeaVGABIOS.  The most recent version of SeaVGABIOS from
SeaBIOS git has additional checks for this - can you grab the seabios
git, set CONFIG_DEBUG_LEVEL to 8, build SeaVGABIOS (set
CONFIG_VGA_BOCHS), and post the logs from both Linux and QEMU with the
above options?

-Kevin