From d75757abd01672608289dbed2755bdcf822fb592 Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin" Date: Fri, 11 Dec 2009 14:23:44 -0800 Subject: [PATCH] doc: Add documentation for bootloader_{type,version} Add documentation for kernel/bootloader_type and kernel/bootloader_version to sysctl/kernel.txt. This should really have been done a long time ago. Signed-off-by: H. Peter Anvin Cc: Shen Feng --- Documentation/sysctl/kernel.txt | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt index 8f7a0e73ef4..3894eaa2348 100644 --- a/Documentation/sysctl/kernel.txt +++ b/Documentation/sysctl/kernel.txt @@ -19,6 +19,8 @@ Currently, these files might (depending on your configuration) show up in /proc/sys/kernel: - acpi_video_flags - acct +- bootloader_type [ X86 only ] +- bootloader_version [ X86 only ] - callhome [ S390 only ] - auto_msgmni - core_pattern @@ -93,6 +95,35 @@ valid for 30 seconds. ============================================================== +bootloader_type: + +x86 bootloader identification + +This gives the bootloader type number as indicated by the bootloader, +shifted left by 4, and OR'd with the low four bits of the bootloader +version. The reason for this encoding is that this used to match the +type_of_loader field in the kernel header; the encoding is kept for +backwards compatibility. That is, if the full bootloader type number +is 0x15 and the full version number is 0x234, this file will contain +the value 340 = 0x154. + +See the type_of_loader and ext_loader_type fields in +Documentation/x86/boot.txt for additional information. + +============================================================== + +bootloader_version: + +x86 bootloader version + +The complete bootloader version number. In the example above, this +file will contain the value 564 = 0x234. + +See the type_of_loader and ext_loader_ver fields in +Documentation/x86/boot.txt for additional information. + +============================================================== + callhome: Controls the kernel's callhome behavior in case of a kernel panic.