ArmPkg/Library/ArmSmcLib/AArch64/ArmSmc.S

   1 //
   2 //  Copyright (c) 2012-2014, ARM Limited. All rights reserved.
   3 //
   4 //  SPDX-License-Identifier: BSD-2-Clause-Patent
   5 //
   6 //
   7
   8 #include <AsmMacroIoLibV8.h>
   9
  10 ASM_FUNC(ArmCallSmc)
  11   // Push x0 on the stack - The stack must always be quad-word aligned
  12   str   x0, [sp, #-16]!
  13
  14   // Load the SMC arguments values into the appropriate registers
  15   ldp   x6, x7, [x0, #48]
  16   ldp   x4, x5, [x0, #32]
  17   ldp   x2, x3, [x0, #16]
  18   ldp   x0, x1, [x0, #0]
  19
  20   smc   #0
  21
  22   // Pop the ARM_SMC_ARGS structure address from the stack into x9
  23   ldr   x9, [sp], #16
  24
  25   // Store the SMC returned values into the ARM_SMC_ARGS structure.
  26   // A SMC call can return up to 4 values - we do not need to store back x4-x7.
  27   stp   x2, x3, [x9, #16]
  28   stp   x0, x1, [x9, #0]
  29
  30   mov   x0, x9
  31
  32   ret