This patch contains the documentation for the kexec based crash dump tool.

Quick kdump-howto
================================================================

1) Download and build kexec-tools.

2) Download and build the latest kexec/kdump (-mm) kernel patchset.
   Two kernels need to be built in order to get this feature working.

  A) First kernel:
   a) Enable "kexec system call" feature:
	CONFIG_KEXEC=y
   b) Physical load address (use default):
	CONFIG_PHYSICAL_START=0x100000
   c) Enable "sysfs file system support":
	CONFIG_SYSFS=y
   d) Boot into first kernel with the command line parameter "crashkernel=Y@X":
      For example: "crashkernel=64M@16M".

  B) Second kernel:
   a) Enable "kernel crash dumps" feature:
	CONFIG_CRASH_DUMP=y
   b) Physical load addreess, use same load address as X in "crashkernel"
      kernel parameter in d) above, e.g., 16 MB or 0x1000000.
	CONFIG_PHYSICAL_START=0x1000000
   c) Enable "/proc/vmcore support" (Optional, in Pseudo filesystems).
	CONFIG_PROC_VMCORE=y

3) Boot into the first kernel.

4) Load the second kernel to be booted using:

   kexec -p <second-kernel> --crash-dump --args-linux --append="root=<root-dev>
   maxcpus=1 init 1"

5) System reboots into the second kernel when a panic occurs. A module can be
   written to force the panic, for testing purposes.

6) See Documentation/kdump.txt for how to read the first kernel's
   memory image and how to analyze it.
Signed-off-by: NHariprasad Nellitheertha <hari@in.ibm.com>
Signed-off-by: NEric Biederman <ebiederm@xmission.com>
Signed-off-by: NVivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Nrandy_dunlap <rdunlap@xenotime.net>
Signed-off-by: NManeesh Soni <maneesh@in.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

There's no longer a reason to document the obsolete BK usage.
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Cc: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!