Index: syslinux-4.04/core/localboot.inc
===================================================================
--- syslinux-4.04.orig/core/localboot.inc
+++ syslinux-4.04/core/localboot.inc
@@ -33,6 +33,15 @@ local_boot:
 		cmp ax,-1
 		je .int18
 
+		cmp ax,-2
+		jne .load
+
+		mov al,[DriveNumber]
+		cmp al,80h
+		mov al,80h
+		jnz .load
+		inc ax
+.load:
 		; Load boot sector from the specified BIOS device and jump to it.
 		mov dl,al
 		xor dh,dh