Getting kernels to boot other kernels?

[Ronald G Minnich]

On Thu, 31 Oct 2002, Kevin Hester wrote:

> I recall reading a white paper about Linuxbios and patches so that the kernel
> can boot other kernels?  Does anyone know where this code is?  I've poked
> around with no luck.

just go with kexec, it's the standard now for 2.5. There are other
packages but my inclination is to go with whatever comes with the base
kernel.

> For our application, I'd like to place a minimal kernel into the FLASH with
> the BIOS.  That kernel would either use IP or IDE to read in the 'real'
> kernel.

that's how we do it here. Works quite nicely.

> I considered chaining into Etherboot, but I need to boot from IDE drives in
> addition to Ethernet.  The Etherboot CAN_BOOT_DISK flag seems to require IDE
> read funtionality in the BIOS (a no-no with linuxbios?).

No, there is an ide driver in etherboot. But you get no filesystems.

There is a point of disagreement in this community: is linux too heavy to
be a boot loader, but is its complexity needed; is etherboot a nice and
light and fast bootloader, but is it too simplistic. That is the
disagreement described in its broadest form.

For now, here at lanl, we come down on the side of using Linux wherever
possible and we have been happy with that decision. Just yesterday I had a
problem with etherboot that was solved by using Linux as the bootloader
instead. Overall I prefer using Linux as my bootloader, but I am also
extremely impressed with etherboot's growing capabilities.

ron