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, 1 insertions, 0 deletions

diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index fcf4d92e7e04..6384d25121ca 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -814,6 +814,7 @@ extern unsigned int		BIOS_revision;
 
 /* Boot loader type from the setup header: */
 extern int                      bootloader_type;
+extern int                      bootloader_version;
 
 extern char                     ignore_fpu_irq;