[SeaBIOS] [PATCH] mark VBE mapping as reserved in e820

[Izik Eidus]

On Mon, 25 Jan 2010 05:40:50 +0100
Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006 at gmx.net> wrote:

> On 24.01.2010 18:18, Izik Eidus wrote:
> > On Sun, 24 Jan 2010 17:45:25 +0100
> > Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006 at gmx.net> wrote:
> >   
> >> That looks like a bug. If you're talking about an ISA device, the LFB
> >> must be smaller than 16 MB and its upper end must be at 16 MB or below.
> >> If you only allow power-of-two sizes, the maximum LFB size is 8 MB
> >> located at 8 MB. (LFB size of 16 MB is not allowed because it would mean
> >> the lowest 640 kB are part of the LFB.)
> >> If the device is EISA (instead of ISA) it can work, but I think you need
> >> the full PNPBIOS extensions for it to work (AFAIK isapnptools have
> >> readable docs/code and could help to find out what is needed).
> >>     
> >
> > I think this code probably fall into the eisa catagory,
> >   
> 
> Yes, probably.
> 
> 
> > But I am confused about what the direction you offer to
> > solve this problem.
> >   
> 
> If it is pure ISA, I do not think we can solve the problem unless we
> place a 8 MB LFB at address 8-16 MB.
> If it is EISA, I propose to use the PNPBIOS extensions because most OS
> check these extensions before allocating (PCI) resources.
> 
> 
> > The acpi spec does mention that PNP devices does not have to
> > be reported.
> >   
> 
> Hm. If the PNP devices are not reported in the ACPI tables, they should
> still be visible via the PNPBIOS extensions. We may have to extend the
> VGABIOS or SeaBIOS for this (I didn't check).
> 
> 
> > But considering the qemu code we have right now I think this is
> > the only right fix to make the isa_sta_vga safe.
> >   
> 
> "this" == Adding the devices to the ACPI table?

Yes only the LFB, but anyway I dont mind to fix
this thing using the PNPBIOS.

> 
> Regards,
> Carl-Daniel
>