Index: kernel/arch/amd64/src/boot/memmap.c
===================================================================
--- kernel/arch/amd64/src/boot/memmap.c	(revision 421c8338127caee7f13ab5e70216f4ed042e8b22)
+++ kernel/arch/amd64/src/boot/memmap.c	(revision 8df84159443459b1d42b1bfb7ac53524020c5359)
@@ -35,5 +35,5 @@
 #include <arch/boot/memmap.h>
 
-uint8_t e820counter = 0xff;
+uint8_t e820counter = 0xffU;
 e820memmap_t e820table[MEMMAP_E820_MAX_RECORDS];