From be274eeaf20b4c7155242645d5e2c48b023e609b Mon Sep 17 00:00:00 2001
From: Vivek Goyal <vgoyal@in.ibm.com>
Date: Thu, 7 Dec 2006 02:14:04 +0100
Subject: [PATCH] [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>
---
Documentation/i386/boot.txt | 4 ++++
arch/i386/boot/setup.S | 13 ++++++++++++-
2 files changed, 16 insertions(+), 1 deletion(-)
diff --git a/Documentation/i386/boot.txt b/Documentation/i386/boot.txt
index c51314b1a46..cb28254f155 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.
diff --git a/arch/i386/boot/setup.S b/arch/i386/boot/setup.S
index 9aa8b051818..06edf1c6624 100644
--- a/arch/i386/boot/setup.S
+++ b/arch/i386/boot/setup.S
@@ -81,7 +81,7 @@ 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
@@ -160,6 +160,17 @@ ramdisk_max: .long (-__PAGE_OFFSET-(512 << 20)-1) & 0x7fffffff
# The highest safe address for
# the contents of an initrd
+kernel_alignment: .long CONFIG_PHYSICAL_ALIGN #physical addr alignment
+ #required for protected mode
+ #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
--
2.41.3