feat(optee): add loading OP-TEE image via an SMC

This adds the ability to load the OP-TEE image via an SMC called from
non-secure userspace rather than loading it during boot. This should
only be utilized on platforms that can ensure security is maintained up
until the point the SMC is invoked as it breaks the normal barrier
between the secure and non-secure world.

Signed-off-by: Jeffrey Kardatzke <jkardatzke@google.com>
Change-Id: I21cfa9699617c493fa4190f01d1cbb714e7449cc
diff --git a/services/spd/opteed/teesmc_opteed.h b/services/spd/opteed/teesmc_opteed.h
index c82b58a..eae3ed2 100644
--- a/services/spd/opteed/teesmc_opteed.h
+++ b/services/spd/opteed/teesmc_opteed.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014-2019, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2014-2023, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -9,8 +9,10 @@
 #ifndef TEESMC_OPTEED_H
 #define TEESMC_OPTEED_H
 
+#include "teesmc_opteed_macros.h"
+
 /*
- * This file specifies SMC function IDs used when returning from TEE to the
+ * This section specifies SMC function IDs used when returning from TEE to the
  * secure monitor.
  *
  * All SMC Function IDs indicates SMC32 Calling Convention but will carry
@@ -120,4 +122,39 @@
 #define TEESMC_OPTEED_RETURN_SYSTEM_RESET_DONE \
 	TEESMC_OPTEED_RV(TEESMC_OPTEED_FUNCID_RETURN_SYSTEM_RESET_DONE)
 
+/*
+ * This section specifies SMC function IDs used when the secure monitor is
+ * invoked from the non-secure world.
+ */
+
+/*
+ * Load OP-TEE image from the payload specified in the registers.
+ *
+ * WARNING: Use this cautiously as it could lead to insecure loading of the
+ * Trusted OS. Further details are in opteed.mk.
+ *
+ * Call register usage:
+ * x0 SMC Function ID, OPTEE_SMC_CALL_LOAD_IMAGE
+ * x1 Upper 32bit of a 64bit size for the payload
+ * x2 Lower 32bit of a 64bit size for the payload
+ * x3 Upper 32bit of the physical address for the payload
+ * x4 Lower 32bit of the physical address for the payload
+ *
+ * The payload consists of a optee_header struct that contains optee_image
+ * structs in a flex array, immediately following that in memory is the data
+ * referenced by the optee_image structs.
+ * Example:
+ *
+ * struct optee_header (with n images specified)
+ * image 0 data
+ * image 1 data
+ * ...
+ * image n-1 data
+ *
+ * Returns 0 on success and an error code otherwise.
+ */
+#define NSSMC_OPTEED_FUNCID_LOAD_IMAGE 2
+#define NSSMC_OPTEED_CALL_LOAD_IMAGE \
+	NSSMC_OPTEED_CALL(NSSMC_OPTEED_FUNCID_LOAD_IMAGE)
+
 #endif /*TEESMC_OPTEED_H*/