ArmPkg/Library/OpteeLib/Optee.c

   1 /** @file
   2   Api's to communicate with OP-TEE OS (Trusted OS based on ARM TrustZone) via
   3   secure monitor calls.
   4
   5   Copyright (c) 2018, Linaro Ltd. All rights reserved.<BR>
   6
   7   This program and the accompanying materials
   8   are licensed and made available under the terms and conditions of the BSD License
   9   which accompanies this distribution.  The full text of the license may be found at
  10   http://opensource.org/licenses/bsd-license.php
  11
  12   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  13   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  14
  15 **/
  16
  17 #include <Library/ArmSmcLib.h>
  18 #include <Library/BaseLib.h>
  19 #include <Library/OpteeLib.h>
  20
  21 #include <IndustryStandard/ArmStdSmc.h>
  22
  23 /**
  24   Check for OP-TEE presence.
  25 **/
  26 BOOLEAN
  27 EFIAPI
  28 IsOpteePresent (
  29   VOID
  30   )
  31 {
  32   ARM_SMC_ARGS ArmSmcArgs;
  33
  34   // Send a Trusted OS Calls UID command
  35   ArmSmcArgs.Arg0 = ARM_SMC_ID_TOS_UID;
  36   ArmCallSmc (&ArmSmcArgs);
  37
  38   if ((ArmSmcArgs.Arg0 == OPTEE_OS_UID0) &&
  39       (ArmSmcArgs.Arg1 == OPTEE_OS_UID1) &&
  40       (ArmSmcArgs.Arg2 == OPTEE_OS_UID2) &&
  41       (ArmSmcArgs.Arg3 == OPTEE_OS_UID3)) {
  42     return TRUE;
  43   } else {
  44     return FALSE;
  45   }
  46 }