handle kernelcore=: generic

This patch adds the kernelcore= parameter for x86.

Once all patches are applied, a new command-line parameter exist and a new
sysctl.  This patch adds the necessary documentation.

From: Yasunori Goto <y-goto@jp.fujitsu.com>

  When "kernelcore" boot option is specified, kernel can't boot up on ia64
  because of an infinite loop.  In addition, the parsing code can be handled
  in an architecture-independent manner.

  This patch uses common code to handle the kernelcore= parameter.  It is
  only available to architectures that support arch-independent zone-sizing
  (i.e.  define CONFIG_ARCH_POPULATES_NODE_MAP).  Other architectures will
  ignore the boot parameter.

[bunk@stusta.de: make cmdline_parse_kernelcore() static]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Acked-by: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 1 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index c3f6f851f76e..0a53728a12f5 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -3416,7 +3416,7 @@ void __init free_area_init_nodes(unsigned long *max_zone_pfn)
  * kernelcore=size sets the amount of memory for use for allocations that
  * cannot be reclaimed or migrated.
  */
-int __init cmdline_parse_kernelcore(char *p)
+static int __init cmdline_parse_kernelcore(char *p)
 {
         unsigned long long coremem;
         if (!p)
@@ -3430,6 +3430,9 @@ int __init cmdline_parse_kernelcore(char *p)
 
         return 0;
 }
+
+early_param("kernelcore", cmdline_parse_kernelcore);
+
 #endif /* CONFIG_ARCH_POPULATES_NODE_MAP */
 
 /**