diff --git a/libc/kernel/arch-x86/asm/xen/hypercall.h b/libc/kernel/arch-x86/asm/xen/hypercall.h
index 3c523a8..bb2342c 100644
--- a/libc/kernel/arch-x86/asm/xen/hypercall.h
+++ b/libc/kernel/arch-x86/asm/xen/hypercall.h
@@ -7,28 +7,29 @@
  ***   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 __HYPERCALL_H__
 #define __HYPERCALL_H__
-
 #include <linux/errno.h>
 #include <linux/string.h>
-
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #include <xen/interface/xen.h>
 #include <xen/interface/sched.h>
 #include <xen/interface/physdev.h>
-
 #define _hypercall0(type, name)  ({   long __res;   asm volatile (   "call %[call]"   : "=a" (__res)   : [call] "m" (hypercall_page[__HYPERVISOR_##name])   : "memory" );   (type)__res;  })
-
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define _hypercall1(type, name, a1)  ({   long __res, __ign1;   asm volatile (   "call %[call]"   : "=a" (__res), "=b" (__ign1)   : "1" ((long)(a1)),   [call] "m" (hypercall_page[__HYPERVISOR_##name])   : "memory" );   (type)__res;  })
-
 #define _hypercall2(type, name, a1, a2)  ({   long __res, __ign1, __ign2;   asm volatile (   "call %[call]"   : "=a" (__res), "=b" (__ign1), "=c" (__ign2)   : "1" ((long)(a1)), "2" ((long)(a2)),   [call] "m" (hypercall_page[__HYPERVISOR_##name])   : "memory" );   (type)__res;  })
-
 #define _hypercall3(type, name, a1, a2, a3)  ({   long __res, __ign1, __ign2, __ign3;   asm volatile (   "call %[call]"   : "=a" (__res), "=b" (__ign1), "=c" (__ign2),   "=d" (__ign3)   : "1" ((long)(a1)), "2" ((long)(a2)),   "3" ((long)(a3)),   [call] "m" (hypercall_page[__HYPERVISOR_##name])   : "memory" );   (type)__res;  })
-
 #define _hypercall4(type, name, a1, a2, a3, a4)  ({   long __res, __ign1, __ign2, __ign3, __ign4;   asm volatile (   "call %[call]"   : "=a" (__res), "=b" (__ign1), "=c" (__ign2),   "=d" (__ign3), "=S" (__ign4)   : "1" ((long)(a1)), "2" ((long)(a2)),   "3" ((long)(a3)), "4" ((long)(a4)),   [call] "m" (hypercall_page[__HYPERVISOR_##name])   : "memory" );   (type)__res;  })
-
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define _hypercall5(type, name, a1, a2, a3, a4, a5)  ({   long __res, __ign1, __ign2, __ign3, __ign4, __ign5;   asm volatile (   "call %[call]"   : "=a" (__res), "=b" (__ign1), "=c" (__ign2),   "=d" (__ign3), "=S" (__ign4), "=D" (__ign5)   : "1" ((long)(a1)), "2" ((long)(a2)),   "3" ((long)(a3)), "4" ((long)(a4)),   "5" ((long)(a5)),   [call] "m" (hypercall_page[__HYPERVISOR_##name])   : "memory" );   (type)__res;  })
-
 #endif