LinuxBIOS Bootup

Eric W Biederman ebiederman at
Thu Aug 29 02:12:01 CEST 2002

Balbir Singh writes:
> Hello, List,
> I need the following clarification about the LinuxBios boot up
> information
> 1. Can LinuxBios boot from CDROM?
> 2. Can LinuxBios boot from a SCSI Disk?

Yes.  But the drivers have not yet been written.

> 3. Does anybody have a FAQ or collected information about how the
> LinuxBios
>    bootup sequence works?

Not especially as this is a work in progress, at the moment.

The design:
- All booting under LinuxBIOS will load standalone executables
  that do not need BIOS calls to access the hardware
- Information will be passed in the LinuxBIOS table to the loaded
- The LinuxBIOS core will have a dumb bootloader with one hardware driver
  and it will load static ELF executables, this is to prevent feature
- Either the LinuxBIOS core loads the final kernel, or it loads a bootloader.
- Either the bootloader is stupid and scans ~= the first 8K of a device looking
  for an ELF image to boot, or it is smart and parses filesystems.

On the side of stupid bootloaders, I have just finished enhancing the
development version of etherboot:
So that it has allows the specification of a boot order, (compile
time, run time or a cmos option).  This supports quite a few NICs,
and IDE, and floppies.  Though the code needs a little more
stabalization work.

The bootloader story with LinuxBIOS is a work in progress, but some
good options are starting to emerge.

Adam Agnew, and Ollie Lho have a forked version of etheroboot with
filesystem support.  The infrastructure is in place so it can probably
be merged cleanly.

There is work on using the kernel as a bootloader with a linux booting
linux patch.

I have targeted etherboot first because it can be quite small,
allowing for more options in rom chips.  With every driver compiled in
etherboot is ~= 65KB, and with the eepro100 and the ide driver it is
~= 15KB.


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