x86: use ELF format in compressed images.

Signed-off-by: Ian 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: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 18 insertions, 0 deletions

diff --git a/Documentation/i386/boot.txt b/Documentation/i386/boot.txt
index fc49b79bc1ab..b5f5ba1ea668 100644
--- a/Documentation/i386/boot.txt
+++ b/Documentation/i386/boot.txt
@@ -170,6 +170,8 @@ Offset	Proto	Name		Meaning
 0238/4  2.06+   cmdline_size    Maximum size of the kernel command line
 023C/4  2.07+   hardware_subarch Hardware subarchitecture
 0240/8  2.07+   hardware_subarch_data Subarchitecture-specific data
+0248/4  2.08+   compressed_payload_offset
+024C/4  2.08+   compressed_payload_length
 
 (1) For backwards compatibility, if the setup_sects field contains 0, the
     real value is 4.
@@ -512,6 +514,22 @@ Protocol:	2.07+
 
   A pointer to data that is specific to hardware subarch
 
+Field name:     compressed_payload_offset
+Type:           read
+Offset/size:    0x248/4
+Protocol:       2.08+
+
+  If non-zero then this field contains the offset from the end of the
+  real-mode code to the compressed payload. The compression format
+  should be determined using the standard magic number, currently only
+  gzip is used.
+  
+Field name:     compressed_payload_length
+Type:           read
+Offset/size:    0x24c/4
+Protocol:       2.08+
+
+  The length of the compressed payload.
 
 **** THE KERNEL COMMAND LINE