diff --git a/Documentation/i386/boot.txt b/Documentation/i386/boot.txt
index b5f5ba1..05c24df 100644
--- a/Documentation/i386/boot.txt
+++ b/Documentation/i386/boot.txt
@@ -531,6 +531,14 @@
 
   The length of the compressed payload.
 
+**** THE IMAGE CHECKSUM
+
+From boot protocol version 2.08 onwards the CRC-32 is calculated over
+the entire file using the characteristic polynomial 0x04C11DB7 and an
+initial remainder of 0xffffffff.  The checksum is appended to the
+file; therefore the CRC of the file up to the limit specified in the
+syssize field of the header is always 0.
+
 **** THE KERNEL COMMAND LINE
 
 The kernel command line has become an important way for the boot