Supporting extension ROMs and beyond...

Adam Agnew agnew at
Thu Aug 7 16:13:01 CEST 2003

On Fri, 8 Aug 2003, SONE Takeshi wrote:

> I guess, in this direction of development, you will most certainly
> have to implement more legacy BIOS services (realmode INTxx).
> And, once SCSI BIOS worked, you automatically get INT13
> (disk services) because SCSI BIOS hooks it.
> You already have INT10 (video services) by external VGA BIOS.
> Also you already have IDE and floppy drivers to implement your own
> INT13.
> OTOH, loading first sector of first drive into 0x7c00
> and jumping into it is an easy task, because you already have pieces of code
> to support it (realmode switching, bounce buffer, etc.)
> So, will you add a few more legacy services to run LILO and bzImage
> directly from LinuxBIOS? Even more services to boot Windows?
> What do you think?

No one really wants LinuxBIOS to support legacy BIOS services. However,
the need for them keeps creeping in (I believe Ron plans to add int15 to
have better support for some vga roms). In the meantime, with a little
hacking you can probably get LinuxBIOS working with Bochs BIOS to do the
same job. Please see freebios/util/ADLO, it currently works for booting
Windows 2000 on SiS630 boards with LinuxBIOS and you probably only need
to make a few changes in loader.S to get it to work on your board too.

- Adam Agnew

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