Erik Andersen <andersen@codepoet.org> writes:
> On Thu Nov 09, 2000 at 01:18:24AM -0700, Eric W. Biederman wrote:
> >
> > I have recently developed a patch that allows linux to directly boot
> > into another linux kernel.
>
> Looks very cool. I'm curious about your decision to use ELF images. This
> makes it much less conveinient to use due to the kernel postprocessing, and
> makes it that the kernel binary from which you initially boot is not
> necessirily the same as the binary that you re-boot into.
The decision here was that I needed to pass a vector of
<physical address, length, data> pairs. The elf program header
is dead simple and provides it. So I either had to invent a
complicated argument passing mechanism for a syscall or have the
kernel parse a file.
> Wouldn't it be more reasonable to simply try to exec whatever file is provided?
> If the concern is initrds; they can be simply pasted into the kernel binary.
That's exactly what my preprocessing does.
vmlinux is also an elf binary. As is arch/i386/boot/bvmlinux but it
is compressed.
All mkelfImage does is the pasting of initrd's, command lines,
and just a touch of argument conversion code.
What I don't do deliberately is allow or need setup.S which does
syscalls to run. All it does are BIOS calls, and store them in a
nasty data structure. I have replaced that data structure with
something that is maintainable.
I would like very much to not need mkelfImage. However that
requires further changes to the kernel, and I cannot boot an unpatched
kernel with that method.
Eric
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Wed Nov 15 2000 - 21:00:28 EST