booting other oses

[Jakob Praher]

hi all,

how/where does linuxbios do the loading of other oses?
linuxbios loads the linux kernel from the flashrom, which then it is in
real mode imho.
so does it use lobos/two kernel monte or something other way to load
another app?

I would apprieciate source code pointers or other directions where I can
look for.

for instance how would linuxbios boot into for instance grub or lilo?

thanks
--Jakob

[Stefan Reinauer]

* Jakob Praher  [040825 09:31]:
> how/where does linuxbios do the loading of other oses?

LinuxBIOS can load an arbitrary static ELF binary from flash or disk.
> linuxbios loads the linux kernel from the flashrom, which then it is in
> real mode imho.

It can also load a bootloader from flash, like etherboot, filo or
start openbios. This is all in protected mode though. Real mode is gone
for good 17 instructions after power-on
> for instance how would linuxbios boot into for instance grub or lilo?

grub and lilo both don't work in LinuxBIOS since they are using PCBIOS
16bit callbacks ("interrupts") for IO. If you want to use those anyways,
have a look at ADLO

(See mailing list archive for above phrases ;)

Stefan

[Jakob Praher]

hi Stefan,

thanks für the info.
I have included some additional questions.
but lets summarize what I think I know:
linuxbios is a bootstrapper thats able to load a linux kernel/elf binary
from within a flash rom/file/...? 
or is linuxbios itself a linux kernel that is able to execute another
elf binary?
if the first option is true, it would probably need hardware access code
for accessing ide/scsi disks without the 16bit callbacks (INT13 and
friends)

Am Mit, den 25.08.2004 schrieb Stefan Reinauer um 11:26:
> Jakob Praher  [040825 09:31]:
> > how/where does linuxbios do the loading of other oses?
>
> LinuxBIOS can load an arbitrary static ELF binary from flash or disk.

how do you then be able to load ntldr or something like that?
afaik ntldr is no elf executable it is either a COFF/PE or it is a DOS
exe ...
> > linuxbios loads the linux kernel from the flashrom, which then it is in
> > real mode imho.
>
> It can also load a bootloader from flash, like etherboot, filo or
> start openbios. This is all in protected mode though. Real mode is gone
> for good 17 instructions after power-on

thats good to know.
> > for instance how would linuxbios boot into for instance grub or lilo?
>
> grub and lilo both don't work in LinuxBIOS since they are using PCBIOS
> 16bit callbacks ("interrupts") for IO. If you want to use those anyways,
> have a look at ADLO

I understand. so what is the preferred boot loader with linuxbios?
> (See mailing list archive for above phrases ;)

hehe.

-- Jakob
>

[ron minnich]

On Wed, 25 Aug 2004, Jakob Praher wrote:
> linuxbios loads the linux kernel from the flashrom, which then it is in
> real mode imho.

ah, no, it is not. it is in 32-bit mode in linuxbios, and 32-bit paged 
mode in kernel.
> so does it use lobos/two kernel monte or something other way to load
> another app?

app ==> kernel right?
> for instance how would linuxbios boot into for instance grub or lilo?

it won't because grub and lilo need bios callbacks that linuxbios does not 
provide.

ron