MdePkg/Library/BaseCpuLib/Arm/CpuSleep.S

   1 #------------------------------------------------------------------------------
   2 #
   3 # CpuSleep() for ARMv7
   4 #
   5 # ARMv6 versions was:
   6 #    MOV r0,#0
   7 #    MCR p15,0,r0,c7,c0,4   ;Wait for Interrupt instruction
   8 #
   9 # But this is a no-op on ARMv7
  10 #
  11 # Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
  12 # Portions copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
  13 # This program and the accompanying materials
  14 # are licensed and made available under the terms and conditions of the BSD License
  15 # which accompanies this distribution.  The full text of the license may be found at
  16 # http://opensource.org/licenses/bsd-license.php.
  17 #
  18 # THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  19 # WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  20 #
  21 #------------------------------------------------------------------------------
  22
  23 .text
  24 .p2align 2
  25 GCC_ASM_EXPORT(CpuSleep)
  26
  27 #/**
  28 #  Places the CPU in a sleep state until an interrupt is received.
  29 #
  30 #  Places the CPU in a sleep state until an interrupt is received. If interrupts
  31 #  are disabled prior to calling this function, then the CPU will be placed in a
  32 #  sleep state indefinitely.
  33 #
  34 #**/
  35 #VOID
  36 #EFIAPI
  37 #CpuSleep (
  38 #  VOID
  39 #  );
  40 #
  41 ASM_PFX(CpuSleep):
  42     wfi
  43     bx  lr