diff --git a/libc/kernel/arch-arm/asm/vga.h b/libc/kernel/arch-arm/asm/vga.h
index 7875dbf..c938da9 100644
--- a/libc/kernel/arch-arm/asm/vga.h
+++ b/libc/kernel/arch-arm/asm/vga.h
@@ -7,17 +7,22 @@
  ***   structures, and macros generated from the original header, and thus,
  ***   contains no copyrightable information.
  ***
+ ***   To edit the content of this header, modify the corresponding
+ ***   source file (e.g. under external/kernel-headers/original/) then
+ ***   run bionic/libc/kernel/tools/update_all.py
+ ***
+ ***   Any manual change here will be lost the next time this script will
+ ***   be run. You've been warned!
+ ***
  ****************************************************************************
  ****************************************************************************/
 #ifndef ASMARM_VGA_H
 #define ASMARM_VGA_H
-
 #include <asm/hardware.h>
 #include <asm/io.h>
-
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define VGA_MAP_MEM(x,s) (PCIMEM_BASE + (x))
-
 #define vga_readb(x) (*((volatile unsigned char *)x))
 #define vga_writeb(x,y) (*((volatile unsigned char *)y) = (x))
-
 #endif
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */