This patch exports to userspace the boot loader ID which has been exported
by (b)zImage boot loaders since boot protocol version 2.

It is needed so that update tools that update kernels from vendors know which
bootloader file they need to update; eg right now those tools do all kinds of
hairy heuristics to find out if it's grub or lilo or ..  that installed the
kernel.  Those heuristics are fragile in the presence of more than one
bootloader (which isn't that uncommon in OS upgrade situations).

Tested on i386 and x86-64; as far as I know those are the only
architectures which use zImage/bzImage format.
Signed-Off-By: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>