+/** @file\r
+ Api's to communicate with OP-TEE OS (Trusted OS based on ARM TrustZone) via\r
+ secure monitor calls.\r
+\r
+ Copyright (c) 2018, Linaro Ltd. All rights reserved.<BR>\r
+\r
+ This program and the accompanying materials\r
+ are licensed and made available under the terms and conditions of the BSD License\r
+ which accompanies this distribution. The full text of the license may be found at\r
+ http://opensource.org/licenses/bsd-license.php\r
+\r
+ THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
+ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
+\r
+**/\r
+\r
+#include <Library/ArmSmcLib.h>\r
+#include <Library/BaseLib.h>\r
+#include <Library/OpteeLib.h>\r
+\r
+#include <IndustryStandard/ArmStdSmc.h>\r
+\r
+/**\r
+ Check for OP-TEE presence.\r
+**/\r
+BOOLEAN\r
+EFIAPI\r
+IsOpteePresent (\r
+ VOID\r
+ )\r
+{\r
+ ARM_SMC_ARGS ArmSmcArgs;\r
+\r
+ // Send a Trusted OS Calls UID command\r
+ ArmSmcArgs.Arg0 = ARM_SMC_ID_TOS_UID;\r
+ ArmCallSmc (&ArmSmcArgs);\r
+\r
+ if ((ArmSmcArgs.Arg0 == OPTEE_OS_UID0) &&\r
+ (ArmSmcArgs.Arg1 == OPTEE_OS_UID1) &&\r
+ (ArmSmcArgs.Arg2 == OPTEE_OS_UID2) &&\r
+ (ArmSmcArgs.Arg3 == OPTEE_OS_UID3)) {\r
+ return TRUE;\r
+ } else {\r
+ return FALSE;\r
+ }\r
+}\r