Any UK DiskOnChip Retailers?

Eric W. Biederman ebiederman at
Mon Sep 16 01:21:00 CEST 2002

"Steve M. Gehlbach" <steve at> writes:

> > > How does the disk/net multiplex work? I am not familiar with that.
> >
> > You have never set the boot order in the BIOS?
> > Roughly you have a booloader that can boot off of either the hard
> > driver or
> > the network.
> I guess my question was more about the mechanics of doing it.  Is it
> possible to multiplex without a BIOS, completely within a (no PC-BIOS)
> Etherboot started from linuxbios?  

Yes.  At least in the current development version. 5.1.2+

> And if the answer is yes, then how do you
> specify the disk, partition, and what is the format, etc.

It depends.  The code is still maturing so all of the details have not
been worked out.

My prefered way of doing it is to scan the first 8K for an ELF header
and to find the rest of the image from the pointers within that header.

If there is nothing on one disk etherboot will continue looking at other
possible boot devices.

For the time being I just put a partition at the start of the disk right
after the partition table and everything works.  Likely a better way
to manage this so you can multiple kernels on the hard drive will evolve.

There are some other development version that have been thrown around
by Ollie Lho and Adam Agnew that actually includes a partition and a a
filesystem parser.  Personally I don't think those are necessary in
the firmware, but people who think otherwise are free to implement it.
The code structure in etherboot is now clean enough it should fit in

Mostly I think there is a very large difference between code that
resides in firmware that as a matter of policy you don't want to
update, and you want very simple so you can reuse and verify it is
correct.  And code that you read off of a hard drive that is easy to
update and replace without chance of killing your computer.  And I do
not believe it is appropriate for the system rom to set such a
precedent, when alternatives exist. 

But it is all a policy matter and in the long run I will go with
whatever works.


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