[PATCH] kexec: x86: add CONFIG_PYSICAL_START

For one kernel to report a crash another kernel has created we need
to have 2 kernels loaded simultaneously in memory.  To accomplish this
the two kernels need to built to run at different physical addresses.

This patch adds the CONFIG_PHYSICAL_START option to the x86 kernel
so we can do just that.  You need to know what you are doing and
the ramifications are before changing this value, and most users
won't care so I have made it depend on CONFIG_EMBEDDED

bzImage kernels will work and run at a different address when compiled
with this option but they will still load at 1MB.  If you need a kernel
loaded at a different address as well you need to boot a vmlinux.

Signed-off-by: Eric Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/include/asm-i386/page.h b/include/asm-i386/page.h
index dea8f8e6d86e..8d93f732d72d 100644
--- a/include/asm-i386/page.h
+++ b/include/asm-i386/page.h
@@ -126,9 +126,12 @@ extern int page_is_ram(unsigned long pagenr);
 
 #ifdef __ASSEMBLY__
 #define __PAGE_OFFSET           (0xC0000000)
+#define __PHYSICAL_START        CONFIG_PHYSICAL_START
 #else
 #define __PAGE_OFFSET           (0xC0000000UL)
+#define __PHYSICAL_START        ((unsigned long)CONFIG_PHYSICAL_START)
 #endif
+#define __KERNEL_START          (__PAGE_OFFSET + __PHYSICAL_START)
 
 
 #define PAGE_OFFSET             ((unsigned long)__PAGE_OFFSET)