Subject: Re: "helper kernels" that can load GENERIC, etc.
To: Todd Whitesel <>
From: Andrew Gillham <>
List: current-users
Date: 03/20/2000 16:09:28
Todd Whitesel writes:
> > What is the feasibility of having "helper kernels" that can boot
> > another kernel from other media?  e.g. the BIOS supports ABC, but I need
> I think this is a great idea. A stripped-down kernel with a ramdisk root
> would make a much better BIOS than most PC BIOS's...

Well, I don't think we have quite enough low-level hardware info to
replace the BIOS, but I already want to make a "rom monitor" type utility
for i386.  The problem tends to boil down to NVRAM storage. (and my
lack of decent assembler skills)

The helper kernel concept may be architecture dependant.  In looking at
some of the MMEYE code, it seems like these steps are needed:
 Load new kernel image into reserved buffer. (high end of RAM)
 Jump to trampoline code (high end of RAM?)
 Relocate new kernel to normal location
 Jump into new kernel

Presumably the trampoline code needs to shutdown/reinitialize any
RAM/CPU related stuff to what a new kernel would expect.

Andrew Gillham                            | This space left blank                     | inadvertently.
I speak for myself, not for my employer.  | Contact the publisher.