bzip2/lzma: update boot protocol specification
Impact: documentation
Update the boot protocol specification to include the currently
supported file formats and their magic numbers.
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
diff --git a/Documentation/x86/boot.txt b/Documentation/x86/boot.txt
index fcdc62b..9ac70ff 100644
--- a/Documentation/x86/boot.txt
+++ b/Documentation/x86/boot.txt
@@ -542,7 +542,10 @@
The payload may be compressed. The format of both the compressed and
uncompressed data should be determined using the standard magic
- numbers. Currently only gzip compressed ELF is used.
+ numbers. The currently supported compression formats are gzip
+ (magic numbers 1F 8B or 1F 9E), bzip2 (magic number 42 5A) and LZMA
+ (magic number 5D 00). The uncompressed payload is currently always ELF
+ (magic number 7F 45 4C 46).
Field name: payload_length
Type: read