[PATCH 6/10] kdump: x86_64 add elfcorehdr command line option

[Vivek Goyal <vgoyal@in.ibm.com>]

o elfcorehdr= specifies the location of elf core header stored by the
  crashed kernel. This command line option will be passed by the 
  kexec-tools to capture kernel.

Changes in this version :

o Added more comments in kernel-parameters.txt and in code.

Signed-off-by:Murali M Chakravarthy <muralim@in.ibm.com>
Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com>
---

 linux-2.6.15-rc1-1M-dynamic-root/Documentation/kernel-parameters.txt |    7 ++++---
 linux-2.6.15-rc1-1M-dynamic-root/arch/x86_64/kernel/setup.c          |    9 +++++++++
 2 files changed, 13 insertions(+), 3 deletions(-)

diff -puN arch/x86_64/kernel/setup.c~x86_64-elfcorehdr-command-line-option arch/x86_64/kernel/setup.c
--- linux-2.6.15-rc1-1M-dynamic/arch/x86_64/kernel/setup.c~x86_64-elfcorehdr-command-line-option	2005-11-17 11:11:07.000000000 +0530
+++ linux-2.6.15-rc1-1M-dynamic-root/arch/x86_64/kernel/setup.c	2005-11-17 11:11:07.000000000 +0530
@@ -42,6 +42,7 @@
 #include <linux/edd.h>
 #include <linux/mmzone.h>
 #include <linux/kexec.h>
+#include <linux/crash_dump.h>
 
 #include <asm/mtrr.h>
 #include <asm/uaccess.h>
@@ -417,6 +418,14 @@ static __init void parse_cmdline_early (
 		}
 #endif
 
+#ifdef CONFIG_CRASH_DUMP
+		/* elfcorehdr= specifies the location of elf core header
+		 * stored by the crashed kernel. This option will be passed
+		 * by kexec loader to the capture kernel.
+		 */
+		else if(!memcmp(from, "elfcorehdr=", 11))
+			elfcorehdr_addr = memparse(from+11, &from);
+#endif
 	next_char:
 		c = *(from++);
 		if (!c)
diff -puN Documentation/kernel-parameters.txt~x86_64-elfcorehdr-command-line-option Documentation/kernel-parameters.txt
--- linux-2.6.15-rc1-1M-dynamic/Documentation/kernel-parameters.txt~x86_64-elfcorehdr-command-line-option	2005-11-17 11:11:07.000000000 +0530
+++ linux-2.6.15-rc1-1M-dynamic-root/Documentation/kernel-parameters.txt	2005-11-17 11:11:07.000000000 +0530
@@ -475,10 +475,11 @@ running once the system is up.
 			See Documentation/block/as-iosched.txt and
 			Documentation/block/deadline-iosched.txt for details.
 
-	elfcorehdr=	[IA-32]
+	elfcorehdr=	[IA-32, X86_64]
 			Specifies physical address of start of kernel core
-			image elf header.
-			See Documentation/kdump.txt for details.
+			image elf header. Generally kexec loader will
+			pass this option to capture kernel.
+			See Documentation/kdump/kdump.txt for details.
 
 	enforcing	[SELINUX] Set initial enforcing status.
 			Format: {"0" | "1"}
_