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: NH. Peter Anvin <hpa@zytor.com>

Document the new bzImage fields for kernel memory placement.

[ Impact: adds documentation ]
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

Modify field names to the right ones:

 - start_sys was changed to start_sys_seg
 - iinitrd_addr_max was changed to ramdisk_max
 - pad2 was changed to pad2 and pad3
 - readmode_swtch was changed to realmode_swtch
Signed-off-by: NBaodong Chen <[email]chenbdchenbd@gmail.com[email]>
Acked-by: NJiri Kosina <jkosina@suse.cz>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: documentation

Update the boot protocol specification to include the currently
supported file formats and their magic numbers.
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

Signed-off-by: NBaodong Chen <[email]chenbdchenbd@gmail.com[email]>
Acked-by: NJiri Kosina <jkosina@suse.cz>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: clarify documentation

Documentation/x86/boot.txt describes payload_offset as the offset
from the end of the real-mode code. In fact, it is more accurately
described as the offset from the beginning of the protected-mode
code, as (a) this is how it is actually calculated and (b) the padding
after the real-mode code is not included in the offset.
Signed-off-by: NPhilipp Kohlbecher <xt28@gmx.de>
Acked-by: NIan Campbell <ijc@hellion.org.uk>
Acked-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: documentation fix

I met okuji-san (GRUB maintainer) yesterday.
He said GRuB isn't correct spelled and he want to fix it.
Signed-off-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

The start_sys field is two bytes, not four.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

The boot protocol, USB legacy support, and zero-page documentation is
common to the x86 platform, not i386-specific.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

The current organization of the x86 documentation makes it appear as
if the "i386" documentation doesn't apply to x86-64, which is does.
Thus, move that documentation into Documentation/x86, and move the
x86-64-specific stuff into Documentation/x86/x86_64 with the eventual
goal to move stuff that isn't actually 64-bit specific back into
Documentation/x86.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

Document QUIET_FLAG, correct the definition of several fields, make it
clear this applies to the entire x86 architecture, not just i386.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

Signed-off-by: NIan Campbell <ijc@hellion.org.uk>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Acked-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Documentation for linked list of struct setup_data.
Signed-off-by: NHuang Ying <ying.huang@intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Also update field names to simply payload_{offset,length} so as to not rule
out uncompressed images.
Signed-off-by: NIan Campbell <ijc@hellion.org.uk>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: virtualization@lists.linux-foundation.org
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Signed-off-by: NIan Campbell <ijc@hellion.org.uk>
Cc: Ian Campbell <ijc@hellion.org.uk>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: virtualization@lists.linux-foundation.org
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: virtualization@lists.linux-foundation.org
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

This patch documents the 32-bit boot protocol of x86. It has been used
by Kexec and LinuxBIOS. This patch is based on the proposal of Peter
Anvin.
Signed-off-by: NHuang Ying <ying.huang@intel.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Updates for version 2.07 of the boot protocol.  This includes:

load_flags.KEEP_SEGMENTS- flag to request/inhibit segment reloads
hardware_subarch	- what subarchitecture we're booting under
hardware_subarch_data	- per-architecture data

The intention of these changes is to make booting a paravirtualized
kernel work via the normal Linux boot protocol.
Signed-off-by: NJeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Acked-by: NH. Peter Anvin <hpa@zytor.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Textual clarifications (and fix an off-by-one error) based on feedback
mostly from Jeremy Fitzhardinge.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

A number of items in the i386 boot documentation have been either
vague, outdated or hard to read.  This text revision adds several more
examples, including a memory map for a modern kernel load.  It also
adds a field-by-field detailed description of the setup header, and a
bootloader ID for Qemu.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In the process of rewriting the x86 setup code, I found a number of
inaccuracies and outdated recommendations in the boot protocol
documentation.  Revamp to make it more up to date.

In particular, the common use of the heap actually requires (slightly)
more than 4K of heap plus stack, which is the recommended amount in
the document; currently the code compensates by being smaller than
specified, but we can't assume that will be true forever.  Thus,
recommend that if we have a modern bzImage kernel, that the bootloader
maximizes the available space.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Because the command line is increased to 2048 characters after 2.6.21, it's
not possible for boot loaders and userspace tools to determine the length
of the command line the kernel can understand.  The benefit of knowing the
length is that users can be warned if the command line size is too long
which prevents surprise if things don't work after bootup.

This patch updates the boot protocol to contain a field called
"cmdline_size" that contain the length of the command line (excluding the
terminating zero).

The patch also adds missing fields (of protocol version 2.05) to the x86_64
setup code.
Signed-off-by: NBernhard Walle <bwalle@suse.de>
Signed-off-by: NAndi Kleen <ak@suse.de>
Cc: Alon Bar-Lev <alon.barlev@gmail.com>
Acked-by: NH. Peter Anvin <hpa@zytor.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>

Add an official boot loader ID for Gujin.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Correct the documentation for bzImage protocol extension due to relocatable
bzImage.
Signed-off-by: NVivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Acked-by: N"H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>

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: NVivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>

Claim an ID number for Xen in the LOADER_TYPE field.

Also, keep the table in zero-page.txt consistent with boot.txt.

[hpa says: 6 was skipped because I couldn't rule out that it hadn't been
 unofficially used.  It seemed easier to skip it for now.]
Signed-off-by: NJeremy Fitzhardinge <jeremy@xensource.com>
Acked-by: N"H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Cc: Frank Sorenson <frank@tuxrocks.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!