[PATCH] i386: extend bzImage protocol for relocatable protected mode kernel

Extend bzImage protocol to enable bootloaders to load a completely relocatable
bzImage.  Now protected mode component of kernel is also relocatable and a
boot-loader can load the protected mode component at a differnt physical
address than 1MB.  (If kernel was built with CONFIG_RELOCATABLE)

Kexec can make use of it to load this kernel at a different physical address
to capture kernel crash dumps.

Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/Documentation/i386/boot.txt b/Documentation/i386/boot.txt
index c51314b1a463..cb28254f1550 100644
--- a/Documentation/i386/boot.txt
+++ b/Documentation/i386/boot.txt
@@ -35,6 +35,8 @@ Protocol 2.03:	(Kernel 2.4.18-pre1) Explicitly makes the highest possible
                 initrd address available to the bootloader.
 
 Protocol 2.04:  (Kernel 2.6.14) Extend the syssize field to four bytes.
+Protocol 2.05:  (Kernel 2.6.20) Make protected mode kernel relocatable.
+                Introduce relocatable_kernel and kernel_alignment fields.
 
 
 **** MEMORY LAYOUT
@@ -129,6 +131,8 @@ Offset	Proto	Name		Meaning
 0226/2  N/A     pad1            Unused
 0228/4  2.02+   cmd_line_ptr    32-bit pointer to the kernel command line
 022C/4  2.03+   initrd_addr_max Highest legal initrd address
+0230/4  2.04+   kernel_alignment Physical addr alignment required for kernel
+0234/1  2.04+   relocatable_kernel Whether kernel is relocatable or not
 
 (1) For backwards compatibility, if the setup_sects field contains 0, the
     real value is 4.