diff --git a/libc/kernel/arch-arm/asm/dma.h b/libc/kernel/arch-arm/asm/dma.h
index 7eeeb78..f23c8fe 100644
--- a/libc/kernel/arch-arm/asm/dma.h
+++ b/libc/kernel/arch-arm/asm/dma.h
@@ -7,39 +7,40 @@
  ***   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 __ASM_ARM_DMA_H
 #define __ASM_ARM_DMA_H
-
 typedef unsigned int dmach_t;
-
 #include <linux/spinlock.h>
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #include <asm/system.h>
 #include <asm/scatterlist.h>
 #include <asm/arch/dma.h>
-
 #ifndef MAX_DMA_ADDRESS
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define MAX_DMA_ADDRESS 0xffffffff
 #endif
-
 typedef unsigned int dmamode_t;
-
 #define DMA_MODE_MASK 3
-
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define DMA_MODE_READ 0
 #define DMA_MODE_WRITE 1
 #define DMA_MODE_CASCADE 2
 #define DMA_AUTOINIT 4
-
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define clear_dma_ff(channel)
-
 #define set_dma_addr(channel, addr)   __set_dma_addr(channel, bus_to_virt(addr))
-
 #ifndef NO_DMA
 #define NO_DMA 255
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #endif
-
 #define isa_dma_bridge_buggy (0)
-
 #endif