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 # SPDX-License-Identifier: BSD-2-Clause-Patent
  14 #
  15 #------------------------------------------------------------------------------
  16
  17 .text
  18 .p2align 2
  19 GCC_ASM_EXPORT(CpuSleep)
  20
  21 #/**
  22 #  Places the CPU in a sleep state until an interrupt is received.
  23 #
  24 #  Places the CPU in a sleep state until an interrupt is received. If interrupts
  25 #  are disabled prior to calling this function, then the CPU will be placed in a
  26 #  sleep state indefinitely.
  27 #
  28 #**/
  29 #VOID
  30 #EFIAPI
  31 #CpuSleep (
  32 #  VOID
  33 #  );
  34 #
  35 ASM_PFX(CpuSleep):
  36     wfi
  37     bx  lr