[PATCH] x86-64: Extend bzImage protocol for relocatable bzImage

o Extend the bzImage protocol (same as i386) to allow bzImage loaders to
  load the protected mode kernel at non-1MB address. Now protected mode
  component is relocatable and can be loaded at non-1MB addresses.

o As of today kdump uses it to run a second kernel from a reserved memory
  area.

Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Andi Kleen <ak@suse.de>

1 files changed, 11 insertions, 2 deletions

diff --git a/arch/x86_64/boot/setup.S b/arch/x86_64/boot/setup.S
index 770940cc0108..deb3573c7aec 100644
--- a/arch/x86_64/boot/setup.S
+++ b/arch/x86_64/boot/setup.S
@@ -80,7 +80,7 @@ start:
 # This is the setup header, and it must start at %cs:2 (old 0x9020:2)
 
                 .ascii  "HdrS"          # header signature
-                .word   0x0204          # header version number (>= 0x0105)
+                .word   0x0205          # header version number (>= 0x0105)
                                         # or else old loadlin-1.5 will fail)
 realmode_swtch: .word   0, 0            # default_switch, SETUPSEG
 start_sys_seg:  .word   SYSSEG
@@ -155,7 +155,16 @@ cmd_line_ptr:	.long 0			# (Header version 0x0202 or later)
                                         # low memory 0x10000 or higher.
 
 ramdisk_max:    .long 0xffffffff
-        
+kernel_alignment:  .long 0x200000       # physical addr alignment required for
+                                        # protected mode relocatable kernel
+#ifdef CONFIG_RELOCATABLE
+relocatable_kernel:    .byte 1
+#else
+relocatable_kernel:    .byte 0
+#endif
+pad2:                  .byte 0
+pad3:                  .word 0
+
 trampoline:     call    start_of_setup
                 .align 16
                                         # The offset at this point is 0x240