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>

1 files changed, 2 insertions, 1 deletions

diff --git a/arch/x86/include/asm/bootparam.h b/arch/x86/include/asm/bootparam.h
index 433adae..1724e8d 100644
--- a/arch/x86/include/asm/bootparam.h
+++ b/arch/x86/include/asm/bootparam.h
@@ -50,7 +50,8 @@ struct setup_header {
 	__u32	ramdisk_size;
 	__u32	bootsect_kludge;
 	__u16	heap_end_ptr;
-	__u16	_pad1;
+	__u8	ext_loader_ver;
+	__u8	ext_loader_type;
 	__u32	cmd_line_ptr;
 	__u32	initrd_addr_max;
 	__u32	kernel_alignment;