In order to work around old LILO versions providing an invalid ss
register, the current setup code always sets up a new stack,
immediately following .bss and the heap. But this breaks LOADLIN.
This rewrite of the workaround checks for an invalid stack (ss!=ds)
first, and leaves ss:sp alone otherwise (apart from aligning esp).
[hpa note: LOADLIN has a number of arbitrary hard-coded limits that
are being pushed up against. Without some major revision of LOADLIN
itself it will not be sustainable keeping it alive. This gives it
another brief lease on life, however. This patch also helps the
cmdline truncation problem with old versions of SYSLINUX.]
Signed-off-by: Jens Rottmann <JRottmann at LiPPERT-AT. de>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Apparently some specific versions of LILO enter the kernel with a
stack pointer that doesn't match the rest of the segments. Make our
best attempt at untangling the resulting mess.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
This patch uses the updated boot protocol to do paravirtualized boot.
If the boot version is >= 2.07, then it will do two things:
1. Check the bootparams loadflags to see if we should reload the
segment registers and clear interrupts. This is appropriate
for normal native boot and some paravirtualized environments, but
inapproprate for others.
2. Check the hardware architecture, and dispatch to the appropriate
kernel entrypoint. If the bootloader doesn't set this, then we
simply do the normal boot sequence.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@in.ibm.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Zachary Amsden <zach@vmware.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
