diff --git a/ChangeLog b/ChangeLog
index a16d5392c..c0f0ba472 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2009-06-12  Vladimir Serbinenko  <phcoder@gmail.com>
+
+	* commands/i386/pc/drivemap_int13h.S: add more comments
+
 2009-06-11  Pavel Roskin  <proski@gnu.org>
 
 	* Makefile.in (uninstall): Uninstall manuals.
diff --git a/commands/i386/pc/drivemap_int13h.S b/commands/i386/pc/drivemap_int13h.S
index 8d360e752..542da0900 100644
--- a/commands/i386/pc/drivemap_int13h.S
+++ b/commands/i386/pc/drivemap_int13h.S
@@ -56,6 +56,7 @@ not_found:
 	pop	%bx
 	pop	%ax
 
+	/* If the call isn't ah=0x8 or ah=0x15 we must restore %dx.  */
 	cmpb	$0x8, %ah
 	jz	norestore
 	cmpb	$0x15, %ah
@@ -71,7 +72,7 @@ not_found:
 	mov	%sp, %bp
 
 tail:
-
+	/* Save new flags below %esp so the caller will recieve new flags.  */
 	pushf
 	pop	%dx
 	mov	%dx, 8(%bp)
@@ -93,7 +94,7 @@ norestore:
 	push	%bp
 	mov	%sp, %bp
 
-	/* Save %dx.  */
+	/* Save %dx. So it won't be restored to original value.  */
 	mov	%dx, 2(%bp)
 
 	jmp tail