ArmPkg/Library/ArmHvcLib/AArch64/ArmHvc.S

   1 //
   2 //  Copyright (c) 2012-2014, ARM Limited. All rights reserved.
   3 //  Copyright (c) 2014-2016, Linaro Limited. All rights reserved.
   4 //
   5 //  SPDX-License-Identifier: BSD-2-Clause-Patent
   6 //
   7 //
   8
   9 #include <AsmMacroIoLibV8.h>
  10
  11 ASM_FUNC(ArmCallHvc)
  12   // Push x0 on the stack - The stack must always be quad-word aligned
  13   str   x0, [sp, #-16]!
  14
  15   // Load the HVC arguments values into the appropriate registers
  16   ldp   x6, x7, [x0, #48]
  17   ldp   x4, x5, [x0, #32]
  18   ldp   x2, x3, [x0, #16]
  19   ldp   x0, x1, [x0, #0]
  20
  21   hvc   #0
  22
  23   // Pop the ARM_HVC_ARGS structure address from the stack into x9
  24   ldr   x9, [sp], #16
  25
  26   // Store the HVC returned values into the ARM_HVC_ARGS structure.
  27   // A HVC call can return up to 4 values
  28   stp   x2, x3, [x9, #16]
  29   stp   x0, x1, [x9, #0]
  30
  31   mov   x0, x9
  32
  33   ret