[PATCH] [21/22] x86_64: Extend bzImage protocol for relocatable bzImage

From: Andi Kleen
Date: Sat Apr 28 2007 - 14:03:04 EST

From: Vivek Goyal <vgoyal@xxxxxxxxxx>

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

Signed-off-by: Vivek Goyal <vgoyal@xxxxxxxxxx>
Signed-off-by: Vivek Goyal <vgoyal@xxxxxxxxxx>
Signed-off-by: Andi Kleen <ak@xxxxxxx>


arch/x86_64/boot/setup.S | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)

Index: linux/arch/x86_64/boot/setup.S
--- linux.orig/arch/x86_64/boot/setup.S
+++ linux/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 versio
# low memory 0x10000 or higher.

ramdisk_max: .long 0xffffffff
+kernel_alignment: .long 0x200000 # physical addr alignment required for
+ # protected mode relocatable kernel
+relocatable_kernel: .byte 1
+relocatable_kernel: .byte 0
+pad2: .byte 0
+pad3: .word 0
trampoline: call start_of_setup
.align 16
# The offset at this point is 0x240
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