linux/arch/powerpc
Mohan Kumar M 54622f10a6 powerpc: Support for relocatable kdump kernel
This adds relocatable kernel support for kdump. With this one can
use the same regular kernel to capture the kdump. A signature (0xfeed1234)
is passed in r6 from panic code to the next kernel through kexec_sequence
and purgatory code. The signature is used to differentiate between
kdump kernel and non-kdump kernels.

The purgatory code compares the signature and sets the __kdump_flag in
head_64.S.  During the boot up, kernel code checks __kdump_flag and if it
is set, the kernel will behave as relocatable kdump kernel. This kernel
will boot at the address where it was loaded by kexec-tools ie. at the
address reserved through crashkernel boot parameter.

CONFIG_CRASH_DUMP depends on CONFIG_RELOCATABLE option to build kdump
kernel as relocatable. So the same kernel can be used as production and
kdump kernel.

This patch incorporates the changes suggested by Paul Mackerras to avoid
GOT use and to avoid two copies of the code.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Mohan Kumar M <mohan@in.ibm.com>
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-10-22 15:01:22 +11:00
..
boot powerpc: Add del_node() for early boot code to prune inapplicable devices. 2008-10-22 15:01:21 +11:00
configs powerpc/40x: Add support for Netstal HCU4 board 2008-10-17 13:28:05 -04:00
include/asm powerpc: Support for relocatable kdump kernel 2008-10-22 15:01:22 +11:00
kernel powerpc: Support for relocatable kdump kernel 2008-10-22 15:01:22 +11:00
kvm KVM: switch to get_user_pages_fast 2008-10-15 14:25:06 +02:00
lib powerpc: Fix DMA offset for non-coherent DMA 2008-10-14 10:35:26 +11:00
math-emu powerpc/math-emu: Use kernel generic math-emu code 2008-10-01 08:40:07 -05:00
mm powerpc: Don't use a 16G page if beyond mem= limits 2008-10-22 15:01:21 +11:00
oprofile powerpc/oprofile: Fix mutex locking for cell spu-oprofile 2008-10-21 15:17:48 +11:00
platforms powerpc: Support for relocatable kdump kernel 2008-10-22 15:01:22 +11:00
sysdev Merge commit 'origin' into master 2008-10-21 15:52:04 +11:00
xmon Merge branch 'linux-2.6' 2008-06-30 10:16:50 +10:00
Kconfig powerpc: Support for relocatable kdump kernel 2008-10-22 15:01:22 +11:00
Kconfig.debug powerpc: Split-out common MSI bitmap logic into msi_bitmap.c 2008-08-20 16:34:57 +10:00
Makefile powerpc: Enforce a non-spe kernel build even on broken compilers 2008-09-15 11:08:41 -07:00