ArmPkg/Library/ArmHvcLib/AArch64/ArmHvc.S

   1 //
   2 //  Copyright (c) 2012-2014, ARM Limited. All rights reserved.
   3 //  Copyright (c) 2014, Linaro Limited. All rights reserved.
   4 //
   5 //  This program and the accompanying materials
   6 //  are licensed and made available under the terms and conditions of the BSD License
   7 //  which accompanies this distribution.  The full text of the license may be found at
   8 //  http://opensource.org/licenses/bsd-license.php
   9 //
  10 //  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11 //  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12 //
  13 //
  14
  15 .text
  16 .align 3
  17
  18 GCC_ASM_EXPORT(ArmCallHvc)
  19
  20 ASM_PFX(ArmCallHvc):
  21   // Push x0 on the stack - The stack must always be quad-word aligned
  22   str   x0, [sp, #-16]!
  23
  24   // Load the HVC arguments values into the appropriate registers
  25   ldp   x6, x7, [x0, #48]
  26   ldp   x4, x5, [x0, #32]
  27   ldp   x2, x3, [x0, #16]
  28   ldp   x0, x1, [x0, #0]
  29
  30   hvc   #0
  31
  32   // Pop the ARM_HVC_ARGS structure address from the stack into x9
  33   ldr   x9, [sp], #16
  34
  35   // Store the HVC returned values into the ARM_HVC_ARGS structure.
  36   // A HVC call can return up to 4 values
  37   stp   x2, x3, [x9, #16]
  38   stp   x0, x1, [x9, #0]
  39
  40   mov   x0, x9
  41
  42   ret