Skip to content

Commit

Permalink
---
Browse files Browse the repository at this point in the history
yaml
---
r: 3342
b: refs/heads/master
c: d58831e
h: refs/heads/master
v: v3
  • Loading branch information
Vivek Goyal authored and Linus Torvalds committed Jun 25, 2005
1 parent 7a31c07 commit 4d71341
Show file tree
Hide file tree
Showing 2 changed files with 18 additions and 12 deletions.
2 changes: 1 addition & 1 deletion [refs]
Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: b089f4a68eccd9782c89262c0d7cae146d5a8a40
refs/heads/master: d58831e4163699de204dea199be2e903bf5d6eff
28 changes: 17 additions & 11 deletions trunk/Documentation/kdump/kdump.txt
Original file line number Diff line number Diff line change
Expand Up @@ -66,33 +66,39 @@ SETUP
CONFIG_PHYSICAL_START=0x1000000
c) Enable "/proc/vmcore support" (Optional, in Pseudo filesystems).
CONFIG_PROC_VMCORE=y

Note: Options a) and b) depend upon "Configure standard kernel features
(for small systems)" (under General setup).
Option a) also depends on CONFIG_HIGHMEM (under Processor
d) Disable SMP support and build a UP kernel (Until it is fixed).
CONFIG_SMP=n
e) Enable "Local APIC support on uniprocessors".
CONFIG_X86_UP_APIC=y
f) Enable "IO-APIC support on uniprocessors"
CONFIG_X86_UP_IOAPIC=y

Note: i) Options a) and b) depend upon "Configure standard kernel features
(for small systems)" (under General setup).
ii) Option a) also depends on CONFIG_HIGHMEM (under Processor
type and features).
Both option a) and b) are under "Processor type and features".
iii) Both option a) and b) are under "Processor type and features".

3) Boot into the first kernel. You are now ready to try out kexec-based crash
dumps.

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"
init 1 irqpoll"

Note: i) <second-kernel> has to be a vmlinux image. bzImage will not work,
as of now.
ii) By default ELF headers are stored in ELF32 format (for i386). This
is sufficient to represent the physical memory up to 4GB. To store
headers in ELF64 format, specifiy "--elf64-core-headers" on the
kexec command line additionally.
iii) For now (or until it is fixed), it's best to build the
second-kernel without multi-processor support, i.e., make it
a uniprocessor kernel.
iii) Specify "irqpoll" as command line parameter. This reduces driver
initialization failures in second kernel due to shared interrupts.

5) System reboots into the second kernel when a panic occurs. A module can be
written to force the panic, for testing purposes.
written to force the panic or "ALT-SysRq-c" can be used initiate a crash
dump for testing purposes.

6) Write out the dump file using

Expand Down Expand Up @@ -131,5 +137,5 @@ TODO
CONTACT
=======

Hariprasad Nellitheertha - hari at in dot ibm dot com
Vivek Goyal (vgoyal@in.ibm.com)
Maneesh Soni (maneesh@in.ibm.com)

0 comments on commit 4d71341

Please sign in to comment.