> The only bios dependency that I know of is that the bios determines how to
> boot your OS (Linux, DOS, or whatever). It generally reads the MBR from
> the hard disk or floppy disk to find out where the executable lives on the
> physical media. It then loads that code to RAM and runs it. Once the
> linux kernel is running I don't think there is much dependecy on the bios.
>
> This is what I believe, but I can not guarantee it.
>
> Brendan Simon.
The bios also configures the chipset's registers to be used in this system.
If you want to remove the bios. You will need to configure the chipset
manually and before the OS runs. Not doing so will cause unpredictable
results. Also do not forget to load the SMM interrupt vectors and handling
subroutines. Currently the Pentium processor wants to jump to memory
location 0x38000 to perform the SMM interrupt handling subroutine. If you
do not have something there, crash. Also you'll want to make sure the you
set the chipsets registers to not use the memory location for normal use.
You would not want to think you have something there and overwrite with
kernel or use space applications. I'm not sure if you can actually protect
that section of memory, so you may want to map 38000 to a8000 and use the
chipset register to make this read only once the subroutine has been copied
to it.
You may ask when would I ever use SMM or something like this: Anytime you
use USB, APM, APCI, etc and most VIA and other chipsets trigger SMM every
10ms to handle legacy USB devices, such as a keyboard, by default when an AT
keyboard is not detected.
In short, removing the BIOS may prove to be a challenging task. You would
probably be better off not removing the BIOS, but writing your own. There
is a GNU BIOS development project I'm sure you could leverage heavily to do
so.
Good luck and let us all know how it goes.
Jim
>
>
>
> Naushit Sakarvadia wrote:
>
> > Hello,
> >
> > Can anybody tell me how much Linux Kernel is dependent on BIOS ?
> > Till I have figure out that for PCI card/.bus it is dependent on Bios
> > what else should
> > I consider if I want to remove BIOS from my Single board computer?
> >
> > And please can anybody tell me how many SBC( single board computers )
> > uses PCI interfaces?
> >
> > Please bear with my ignorance.
> >
> > Thanks in advance.
> >
> > Regards,
> > Naushit
>
>
