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authorH. Peter Anvin <hpa@zytor.com>2009-05-08 03:54:11 +0400
committerH. Peter Anvin <hpa@zytor.com>2009-05-12 04:45:06 +0400
commit5031296c57024a78ddad4edfc993367dbf4abb98 (patch)
tree7506daf7aabf25a5ec567fcd2e644fe22cd91eca /arch/x86/boot/header.S
parentfe83fcc0a14dcf71996de5eb84771b2369ba7abc (diff)
downloadlinux-5031296c57024a78ddad4edfc993367dbf4abb98.tar.xz
x86: add extension fields for bootloader type and version
A long ago, in days of yore, it all began with a god named Thor. There were vikings and boats and some plans for a Linux kernel header. Unfortunately, a single 8-bit field was used for bootloader type and version. This has generally worked without *too* much pain, but we're getting close to flat running out of ID fields. Add extension fields for both type and version. The type will be extended if it the old field is 0xE; the version is a simple MSB extension. Keep /proc/sys/kernel/bootloader_type containing (type << 4) + (ver & 0xf) for backwards compatiblity, but also add /proc/sys/kernel/bootloader_version which contains the full version number. [ Impact: new feature to support more bootloaders ] Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Diffstat (limited to 'arch/x86/boot/header.S')
-rw-r--r--arch/x86/boot/header.S6
1 files changed, 5 insertions, 1 deletions
diff --git a/arch/x86/boot/header.S b/arch/x86/boot/header.S
index a0b426978d55..68c3bfbaff24 100644
--- a/arch/x86/boot/header.S
+++ b/arch/x86/boot/header.S
@@ -169,7 +169,11 @@ heap_end_ptr: .word _end+STACK_SIZE-512
# end of setup code can be used by setup
# for local heap purposes.
-pad1: .word 0
+ext_loader_ver:
+ .byte 0 # Extended boot loader version
+ext_loader_type:
+ .byte 0 # Extended boot loader type
+
cmd_line_ptr: .long 0 # (Header version 0x0202 or later)
# If nonzero, a 32-bit pointer
# to the kernel command line.