Small changes + videobios question...

Richard Smith rsmith at
Sat Oct 9 16:08:00 CEST 2004

Dmitry Zavyalov wrote:

Oh I forgot to ask are you useing V1 or V2?

> RS> Depends.  I've been able to make this work with a couple of
> different RS> video boards but only using ADLO.
> ADLO??? what's it?

If you are usning V1 then:

ADLO is a quasi legacy bios payload for linuxbios.  It comprises of the
BIOS code from the BOCHS project and a glue layer.  In a nutshell ADLO
copies the BOCHS code, Vieo bios, and PIRQ tabled into your BIOS shadow
area, drops back to real mode and jumps to the BOCHS BIOS.  One of the
things the BOCHS bios does is to scan the ROM expansion ranges looking
for extensions and it runs them if it finds them.
BOCHS has a long of legacy compatiblity but its not 100% there yet.

see freebios/utils/ADLO.

ADLO won't run out of the box.  You have to setup your shadowing
properly look through loader.s for the details.

I don't think ADLO has been ported to V2 but since its just a payload 
its probally not a big deal.

> I have CNT69000 integrated on board and 32k video bios image. Just 
> thinking how to put it in.

Chips and Tech (Now Assilaint) 69000 chips work perfectly under ADLO.
That what we used to use.  Are you aware they went end-of-life last year?

> It should work in x86 real mode and must be copied in proper memory
> region. Any ready solution for it or I have to write the code for it
> from zero?

In V1 there also exists a Legacy VGA mode in linuxbios that will setup 
the IDT drop to real mode and run vbios as well but I've not tested it much.

Search the code and the list archives for the following config options:

That ought to give you enough info to you started.

Richard A. Smith

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