diff --git a/docs/components/spd/optee-dispatcher.rst b/docs/components/spd/optee-dispatcher.rst
index 63baccc..81476f1 100644
--- a/docs/components/spd/optee-dispatcher.rst
+++ b/docs/components/spd/optee-dispatcher.rst
@@ -6,9 +6,26 @@
 To build and execute OP-TEE follow the instructions at
 `OP-TEE build.git`_
 
+There are two different modes for loading the OP-TEE OS. The default mode will
+load it as the BL32 payload during boot, and is the recommended technique for
+platforms to use. There is also another technique that will load OP-TEE OS after
+boot via an SMC call by enabling the option for OPTEE_ALLOW_SMC_LOAD that was
+specifically added for ChromeOS. Loading OP-TEE via an SMC call may be insecure
+depending upon the platform configuration. If using that option, be sure to
+understand the risks involved with allowing the Trusted OS to be loaded this
+way. ChromeOS uses a boot flow where it verifies the signature of the firmware
+before executing it, and then only if the signature is valid will the 'secrets'
+used by the TEE become accessible. The firmware then verifies the signature of
+the kernel using depthcharge, and the kernel verifies the rootfs using
+dm-verity.  The SMC call to load OP-TEE is then invoked immediately after the
+kernel finishes loading and before any attack vectors can be opened up by
+mounting writable filesystems or opening network/device connections. this
+ensures the platform is 'closed' and running signed code through the point where
+OP-TEE is loaded.
+
 --------------
 
-*Copyright (c) 2014-2018, Arm Limited and Contributors. All rights reserved.*
+*Copyright (c) 2014-2023, Arm Limited and Contributors. All rights reserved.*
 
 .. _OP-TEE OS: https://github.com/OP-TEE/build
 .. _OP-TEE build.git: https://github.com/OP-TEE/build
diff --git a/docs/threat_model/threat_model.rst b/docs/threat_model/threat_model.rst
index 99bbb3a..0e967ba 100644
--- a/docs/threat_model/threat_model.rst
+++ b/docs/threat_model/threat_model.rst
@@ -918,9 +918,54 @@
 | Mitigations            | | Yes / Platform specific                           |
 +------------------------+-----------------------------------------------------+
 
++------------------------+-----------------------------------------------------+
+| ID                     | 14                                                  |
++========================+=====================================================+
+| Threat                 | | **Security vulnerabilities in the Non-secure OS   |
+|                        |   can lead to secure world compromise if the option |
+|                        |   OPTEE_ALLOW_SMC_LOAD is enabled.**                |
+|                        |                                                     |
+|                        | | This option trusts the non-secure world up until  |
+|                        |   the point it issues the SMC call to load the      |
+|                        |   Secure BL32 payload. If a compromise occurs       |
+|                        |   before the SMC call is invoked, then arbitrary    |
+|                        |   code execution in S-EL1 can occur or arbitrary    |
+|                        |   memory in EL3 can be overwritten.                 |
++------------------------+-----------------------------------------------------+
+| Diagram Elements       | DF5                                                 |
++------------------------+-----------------------------------------------------+
+| Affected TF-A          | BL31, BL32                                          |
+| Components             |                                                     |
++------------------------+-----------------------------------------------------+
+| Assets                 | Code Execution, Sensitive Data                      |
++------------------------+-----------------------------------------------------+
+| Threat Agent           | NSCode                                              |
++------------------------+-----------------------------------------------------+
+| Threat Type            | Tampering, Information Disclosure,                  |
+|                        | Elevation of privilege                              |
++------------------------+-----------------+-----------------+-----------------+
+| Application            | Server          | IoT             | Mobile          |
++------------------------+-----------------+-----------------+-----------------+
+| Impact                 | Critical (5)    | Critical (5)    | Critical (5)    |
++------------------------+-----------------+-----------------+-----------------+
+| Likelihood             | Low (2)         | Low (2)         | Low (2)         |
++------------------------+-----------------+-----------------+-----------------+
+| Total Risk Rating      | Medium (10)     | Medium (10)     | Medium (10)     |
++------------------------+-----------------+-----------------+-----------------+
+| Mitigations            | When enabling the option OPTEE_ALLOW_SMC_LOAD,      |
+|                        | the non-secure OS must be considered a closed       |
+|                        | platform up until the point the SMC can be invoked  |
+|                        | to load OP-TEE.                                     |
++------------------------+-----------------------------------------------------+
+| Mitigations            | | None in TF-A itself. This option is only used by  |
+| implemented?           |   ChromeOS currently which has other mechanisms to  |
+|                        |   to mitigate this threat which are described in    |
+|                        |   `OP-TEE Dispatcher`_.                             |
++------------------------+-----------------------------------------------------+
+
 --------------
 
-*Copyright (c) 2021-2022, Arm Limited. All rights reserved.*
+*Copyright (c) 2021-2023, Arm Limited. All rights reserved.*
 
 
 .. _STRIDE threat analysis technique: https://docs.microsoft.com/en-us/azure/security/develop/threat-modeling-tool-threats#stride-model
@@ -932,3 +977,4 @@
 .. _TF-A error handling policy: https://trustedfirmware-a.readthedocs.io/en/latest/process/coding-guidelines.html#error-handling-and-robustness
 .. _Secure Development Guidelines: https://trustedfirmware-a.readthedocs.io/en/latest/process/security-hardening.html#secure-development-guidelines
 .. _Trusted Firmware-A Tests: https://git.trustedfirmware.org/TF-A/tf-a-tests.git/about/
+.. _OP-TEE Dispatcher: https://github.com/ARM-software/arm-trusted-firmware/blob/master/docs/components/spd/optee-dispatcher.rst
diff --git a/include/lib/optee_utils.h b/include/lib/optee_utils.h
index 06378eb..8224d50 100644
--- a/include/lib/optee_utils.h
+++ b/include/lib/optee_utils.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017-2021, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2017-2023, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -17,4 +17,40 @@
 	image_info_t *pager_image_info,
 	image_info_t *paged_image_info);
 
+/*
+ * load_addr_hi and load_addr_lo: image load address.
+ * image_id: 0 - pager, 1 - paged
+ * size: image size in bytes.
+ */
+typedef struct optee_image {
+	uint32_t load_addr_hi;
+	uint32_t load_addr_lo;
+	uint32_t image_id;
+	uint32_t size;
+} optee_image_t;
+
+#define OPTEE_PAGER_IMAGE_ID		0
+#define OPTEE_PAGED_IMAGE_ID		1
+
+#define OPTEE_MAX_NUM_IMAGES		2u
+
+#define TEE_MAGIC_NUM_OPTEE		0x4554504f
+/*
+ * magic: header magic number.
+ * version: OPTEE header version:
+ *		1 - not supported
+ *		2 - supported
+ * arch: OPTEE os architecture type: 0 - AARCH32, 1 - AARCH64.
+ * flags: unused currently.
+ * nb_images: number of images.
+ */
+typedef struct optee_header {
+	uint32_t magic;
+	uint8_t version;
+	uint8_t arch;
+	uint16_t flags;
+	uint32_t nb_images;
+	optee_image_t optee_image_list[];
+} optee_header_t;
+
 #endif /* OPTEE_UTILS_H */
diff --git a/lib/optee/optee_utils.c b/lib/optee/optee_utils.c
index 6c87b0d..25272fc 100644
--- a/lib/optee/optee_utils.c
+++ b/lib/optee/optee_utils.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017-2022, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2017-2023, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -11,42 +11,6 @@
 
 #include <platform_def.h>
 
-/*
- * load_addr_hi and load_addr_lo: image load address.
- * image_id: 0 - pager, 1 - paged
- * size: image size in bytes.
- */
-typedef struct optee_image {
-	uint32_t load_addr_hi;
-	uint32_t load_addr_lo;
-	uint32_t image_id;
-	uint32_t size;
-} optee_image_t;
-
-#define OPTEE_PAGER_IMAGE_ID		0
-#define OPTEE_PAGED_IMAGE_ID		1
-
-#define OPTEE_MAX_NUM_IMAGES		2u
-
-#define TEE_MAGIC_NUM_OPTEE		0x4554504f
-/*
- * magic: header magic number.
- * version: OPTEE header version:
- *		1 - not supported
- *		2 - supported
- * arch: OPTEE os architecture type: 0 - AARCH32, 1 - AARCH64.
- * flags: unused currently.
- * nb_images: number of images.
- */
-typedef struct optee_header {
-	uint32_t magic;
-	uint8_t version;
-	uint8_t arch;
-	uint16_t flags;
-	uint32_t nb_images;
-	optee_image_t optee_image_list[];
-} optee_header_t;
-
 /*******************************************************************************
  * Check if it is a valid tee header
  * Return true if valid
diff --git a/services/spd/opteed/opteed.mk b/services/spd/opteed/opteed.mk
index 643b054..477b45d 100644
--- a/services/spd/opteed/opteed.mk
+++ b/services/spd/opteed/opteed.mk
@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2013-2019, ARM Limited and Contributors. All rights reserved.
+# Copyright (c) 2013-2023, ARM Limited and Contributors. All rights reserved.
 #
 # SPDX-License-Identifier: BSD-3-Clause
 #
@@ -16,3 +16,19 @@
 
 # required so that optee code can control access to the timer registers
 NS_TIMER_SWITCH		:=	1
+
+# WARNING: This enables loading of OP-TEE via an SMC, which can be potentially
+# insecure. This removes the boundary between the startup of the secure and
+# non-secure worlds until the point where this SMC is invoked. Only use this
+# setting if you can ensure that the non-secure OS can remain trusted up until
+# the point where this SMC is invoked.
+OPTEE_ALLOW_SMC_LOAD		:=	0
+ifeq ($(OPTEE_ALLOW_SMC_LOAD),1)
+ifeq ($(PLAT_XLAT_TABLES_DYNAMIC),0)
+$(error When OPTEE_ALLOW_SMC_LOAD=1, PLAT_XLAT_TABLES_DYNAMIC must also be 1)
+endif
+$(warning "OPTEE_ALLOW_SMC_LOAD is enabled which may result in an insecure \
+	platform")
+$(eval $(call add_define,PLAT_XLAT_TABLES_DYNAMIC))
+$(eval $(call add_define,OPTEE_ALLOW_SMC_LOAD))
+endif
diff --git a/services/spd/opteed/opteed_main.c b/services/spd/opteed/opteed_main.c
index 160a693..ff2aee0 100644
--- a/services/spd/opteed/opteed_main.c
+++ b/services/spd/opteed/opteed_main.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2017, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2023, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -16,6 +16,7 @@
  ******************************************************************************/
 #include <assert.h>
 #include <errno.h>
+#include <inttypes.h>
 #include <stddef.h>
 
 #include <arch_helpers.h>
@@ -24,12 +25,13 @@
 #include <common/debug.h>
 #include <common/runtime_svc.h>
 #include <lib/el3_runtime/context_mgmt.h>
+#include <lib/optee_utils.h>
+#include <lib/xlat_tables/xlat_tables_v2.h>
 #include <plat/common/platform.h>
 #include <tools_share/uuid.h>
 
 #include "opteed_private.h"
 #include "teesmc_opteed.h"
-#include "teesmc_opteed_macros.h"
 
 /*******************************************************************************
  * Address of the entrypoint vector table in OPTEE. It is
@@ -43,7 +45,16 @@
 optee_context_t opteed_sp_context[OPTEED_CORE_COUNT];
 uint32_t opteed_rw;
 
+#if OPTEE_ALLOW_SMC_LOAD
+static bool opteed_allow_load;
+#else
 static int32_t opteed_init(void);
+#endif
+
+uint64_t dual32to64(uint32_t high, uint32_t low)
+{
+	return ((uint64_t)high << 32) | low;
+}
 
 /*******************************************************************************
  * This function is the handler registered for S-EL1 interrupts by the
@@ -93,6 +104,11 @@
  ******************************************************************************/
 static int32_t opteed_setup(void)
 {
+#if OPTEE_ALLOW_SMC_LOAD
+	opteed_allow_load = true;
+	INFO("Delaying OP-TEE setup until we receive an SMC call to load it\n");
+	return 0;
+#else
 	entry_point_info_t *optee_ep_info;
 	uint32_t linear_id;
 	uint64_t opteed_pageable_part;
@@ -142,6 +158,7 @@
 	bl31_register_bl32_init(&opteed_init);
 
 	return 0;
+#endif  /* OPTEE_ALLOW_SMC_LOAD */
 }
 
 /*******************************************************************************
@@ -153,18 +170,12 @@
  * non-secure state. This function performs a synchronous entry into
  * OPTEE. OPTEE passes control back to this routine through a SMC.
  ******************************************************************************/
-static int32_t opteed_init(void)
+static int32_t
+opteed_init_with_entry_point(entry_point_info_t *optee_entry_point)
 {
 	uint32_t linear_id = plat_my_core_pos();
 	optee_context_t *optee_ctx = &opteed_sp_context[linear_id];
-	entry_point_info_t *optee_entry_point;
 	uint64_t rc;
-
-	/*
-	 * Get information about the OPTEE (BL32) image. Its
-	 * absence is a critical failure.
-	 */
-	optee_entry_point = bl31_plat_get_next_image_ep_info(SECURE);
 	assert(optee_entry_point);
 
 	cm_init_my_context(optee_entry_point);
@@ -179,6 +190,115 @@
 	return rc;
 }
 
+#if !OPTEE_ALLOW_SMC_LOAD
+static int32_t opteed_init(void)
+{
+	entry_point_info_t *optee_entry_point;
+	/*
+	 * Get information about the OP-TEE (BL32) image. Its
+	 * absence is a critical failure.
+	 */
+	optee_entry_point = bl31_plat_get_next_image_ep_info(SECURE);
+	return opteed_init_with_entry_point(optee_entry_point);
+}
+#endif  /* !OPTEE_ALLOW_SMC_LOAD */
+
+#if OPTEE_ALLOW_SMC_LOAD
+/*******************************************************************************
+ * This function is responsible for handling the SMC that loads the OP-TEE
+ * binary image via a non-secure SMC call. It takes the size and physical
+ * address of the payload as parameters.
+ ******************************************************************************/
+static int32_t opteed_handle_smc_load(uint64_t data_size, uint32_t data_pa)
+{
+	uintptr_t data_va = data_pa;
+	uint64_t mapped_data_pa;
+	uintptr_t mapped_data_va;
+	uint64_t data_map_size;
+	int32_t rc;
+	optee_header_t *image_header;
+	uint8_t *image_ptr;
+	uint64_t target_pa;
+	uint64_t target_end_pa;
+	uint64_t image_pa;
+	uintptr_t image_va;
+	optee_image_t *curr_image;
+	uintptr_t target_va;
+	uint64_t target_size;
+	entry_point_info_t optee_ep_info;
+	uint32_t linear_id = plat_my_core_pos();
+
+	mapped_data_pa = page_align(data_pa, DOWN);
+	mapped_data_va = mapped_data_pa;
+	data_map_size = page_align(data_size + (mapped_data_pa - data_pa), UP);
+
+	rc = mmap_add_dynamic_region(mapped_data_pa, mapped_data_va,
+				     data_map_size, MT_MEMORY | MT_RO | MT_NS);
+	if (rc != 0) {
+		return rc;
+	}
+
+	image_header = (optee_header_t *)data_va;
+	if (image_header->magic != TEE_MAGIC_NUM_OPTEE ||
+	    image_header->version != 2 || image_header->nb_images != 1) {
+		mmap_remove_dynamic_region(mapped_data_va, data_map_size);
+		return -EINVAL;
+	}
+
+	image_ptr = (uint8_t *)data_va + sizeof(optee_header_t) +
+			sizeof(optee_image_t);
+	if (image_header->arch == 1) {
+		opteed_rw = OPTEE_AARCH64;
+	} else {
+		opteed_rw = OPTEE_AARCH32;
+	}
+
+	curr_image = &image_header->optee_image_list[0];
+	image_pa = dual32to64(curr_image->load_addr_hi,
+			      curr_image->load_addr_lo);
+	image_va = image_pa;
+	target_end_pa = image_pa + curr_image->size;
+
+	/* Now also map the memory we want to copy it to. */
+	target_pa = page_align(image_pa, DOWN);
+	target_va = target_pa;
+	target_size = page_align(target_end_pa, UP) - target_pa;
+
+	rc = mmap_add_dynamic_region(target_pa, target_va, target_size,
+				     MT_MEMORY | MT_RW | MT_SECURE);
+	if (rc != 0) {
+		mmap_remove_dynamic_region(mapped_data_va, data_map_size);
+		return rc;
+	}
+
+	INFO("Loaded OP-TEE via SMC: size %d addr 0x%" PRIx64 "\n",
+	     curr_image->size, image_va);
+
+	memcpy((void *)image_va, image_ptr, curr_image->size);
+	flush_dcache_range(target_pa, target_size);
+
+	mmap_remove_dynamic_region(mapped_data_va, data_map_size);
+	mmap_remove_dynamic_region(target_va, target_size);
+
+	/* Save the non-secure state */
+	cm_el1_sysregs_context_save(NON_SECURE);
+
+	opteed_init_optee_ep_state(&optee_ep_info,
+				   opteed_rw,
+				   image_pa,
+				   0,
+				   0,
+				   0,
+				   &opteed_sp_context[linear_id]);
+	rc = opteed_init_with_entry_point(&optee_ep_info);
+
+	/* Restore non-secure state */
+	cm_el1_sysregs_context_restore(NON_SECURE);
+	cm_set_next_eret_context(NON_SECURE);
+
+	return rc;
+}
+#endif  /* OPTEE_ALLOW_SMC_LOAD */
 
 /*******************************************************************************
  * This function is responsible for handling all SMCs in the Trusted OS/App
@@ -207,6 +327,34 @@
 	 */
 
 	if (is_caller_non_secure(flags)) {
+#if OPTEE_ALLOW_SMC_LOAD
+		if (smc_fid == NSSMC_OPTEED_CALL_LOAD_IMAGE) {
+			/*
+			 * TODO: Consider wiping the code for SMC loading from
+			 * memory after it has been invoked similar to what is
+			 * done under RECLAIM_INIT, but extended to happen
+			 * later.
+			 */
+			if (!opteed_allow_load) {
+				SMC_RET1(handle, -EPERM);
+			}
+
+			opteed_allow_load = false;
+			uint64_t data_size = dual32to64(x1, x2);
+			uint64_t data_pa = dual32to64(x3, x4);
+			if (!data_size || !data_pa) {
+				/*
+				 * This is invoked when the OP-TEE image didn't
+				 * load correctly in the kernel but we want to
+				 * block off loading of it later for security
+				 * reasons.
+				 */
+				SMC_RET1(handle, -EINVAL);
+			}
+			SMC_RET1(handle, opteed_handle_smc_load(
+					data_size, data_pa));
+		}
+#endif  /* OPTEE_ALLOW_SMC_LOAD */
 		/*
 		 * This is a fresh request from the non-secure client.
 		 * The parameters are in x1 and x2. Figure out which
@@ -219,8 +367,18 @@
 
 		/*
 		 * We are done stashing the non-secure context. Ask the
-		 * OPTEE to do the work now.
+		 * OP-TEE to do the work now. If we are loading vi an SMC,
+		 * then we also need to init this CPU context if not done
+		 * already.
 		 */
+		if (optee_vector_table == NULL) {
+			SMC_RET1(handle, -EINVAL);
+		}
+
+		if (get_optee_pstate(optee_ctx->state) ==
+		    OPTEE_PSTATE_UNKNOWN) {
+			opteed_cpu_on_finish_handler(0);
+		}
 
 		/*
 		 * Verify if there is a valid context to use, copy the
diff --git a/services/spd/opteed/opteed_pm.c b/services/spd/opteed/opteed_pm.c
index 719eeb7..fa724a1 100644
--- a/services/spd/opteed/opteed_pm.c
+++ b/services/spd/opteed/opteed_pm.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2017, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2023, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -32,6 +32,10 @@
 	uint32_t linear_id = plat_my_core_pos();
 	optee_context_t *optee_ctx = &opteed_sp_context[linear_id];
 
+	if (get_optee_pstate(optee_ctx->state) == OPTEE_PSTATE_UNKNOWN) {
+		return 0;
+	}
+
 	assert(optee_vector_table);
 	assert(get_optee_pstate(optee_ctx->state) == OPTEE_PSTATE_ON);
 
@@ -65,6 +69,10 @@
 	uint32_t linear_id = plat_my_core_pos();
 	optee_context_t *optee_ctx = &opteed_sp_context[linear_id];
 
+	if (get_optee_pstate(optee_ctx->state) == OPTEE_PSTATE_UNKNOWN) {
+		return;
+	}
+
 	assert(optee_vector_table);
 	assert(get_optee_pstate(optee_ctx->state) == OPTEE_PSTATE_ON);
 
@@ -92,7 +100,7 @@
  * after initialising minimal architectural state that guarantees safe
  * execution.
  ******************************************************************************/
-static void opteed_cpu_on_finish_handler(u_register_t unused)
+void opteed_cpu_on_finish_handler(u_register_t unused)
 {
 	int32_t rc = 0;
 	uint32_t linear_id = plat_my_core_pos();
@@ -100,7 +108,8 @@
 	entry_point_info_t optee_on_entrypoint;
 
 	assert(optee_vector_table);
-	assert(get_optee_pstate(optee_ctx->state) == OPTEE_PSTATE_OFF);
+	assert(get_optee_pstate(optee_ctx->state) == OPTEE_PSTATE_OFF ||
+	       get_optee_pstate(optee_ctx->state) == OPTEE_PSTATE_UNKNOWN);
 
 	opteed_init_optee_ep_state(&optee_on_entrypoint, opteed_rw,
 				(uint64_t)&optee_vector_table->cpu_on_entry,
@@ -134,6 +143,10 @@
 	uint32_t linear_id = plat_my_core_pos();
 	optee_context_t *optee_ctx = &opteed_sp_context[linear_id];
 
+	if (get_optee_pstate(optee_ctx->state) == OPTEE_PSTATE_UNKNOWN) {
+		return;
+	}
+
 	assert(optee_vector_table);
 	assert(get_optee_pstate(optee_ctx->state) == OPTEE_PSTATE_SUSPEND);
 
@@ -173,6 +186,14 @@
 	uint32_t linear_id = plat_my_core_pos();
 	optee_context_t *optee_ctx = &opteed_sp_context[linear_id];
 
+	/*
+	 * OP-TEE must have been initialized in order to reach this location so
+	 * it is safe to init the CPU context if not already done for this core.
+	 */
+	if (get_optee_pstate(optee_ctx->state) == OPTEE_PSTATE_UNKNOWN) {
+		opteed_cpu_on_finish_handler(0);
+	}
+
 	assert(optee_vector_table);
 	assert(get_optee_pstate(optee_ctx->state) == OPTEE_PSTATE_ON);
 
@@ -193,6 +214,14 @@
 	uint32_t linear_id = plat_my_core_pos();
 	optee_context_t *optee_ctx = &opteed_sp_context[linear_id];
 
+	/*
+	 * OP-TEE must have been initialized in order to reach this location so
+	 * it is safe to init the CPU context if not already done for this core.
+	 */
+	if (get_optee_pstate(optee_ctx->state) == OPTEE_PSTATE_UNKNOWN) {
+		opteed_cpu_on_finish_handler(0);
+	}
+
 	assert(optee_vector_table);
 	assert(get_optee_pstate(optee_ctx->state) == OPTEE_PSTATE_ON);
 
diff --git a/services/spd/opteed/opteed_private.h b/services/spd/opteed/opteed_private.h
index 242154f..ab6e4cd 100644
--- a/services/spd/opteed/opteed_private.h
+++ b/services/spd/opteed/opteed_private.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2017, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2023, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -18,9 +18,10 @@
  * OPTEE PM state information e.g. OPTEE is suspended, uninitialised etc
  * and macros to access the state information in the per-cpu 'state' flags
  ******************************************************************************/
-#define OPTEE_PSTATE_OFF		0
-#define OPTEE_PSTATE_ON			1
-#define OPTEE_PSTATE_SUSPEND		2
+#define OPTEE_PSTATE_OFF		1
+#define OPTEE_PSTATE_ON			2
+#define OPTEE_PSTATE_SUSPEND		3
+#define OPTEE_PSTATE_UNKNOWN		0
 #define OPTEE_PSTATE_SHIFT		0
 #define OPTEE_PSTATE_MASK		0x3
 #define get_optee_pstate(state)	((state >> OPTEE_PSTATE_SHIFT) & \
@@ -153,6 +154,7 @@
 				uint64_t mem_limit,
 				uint64_t dt_addr,
 				optee_context_t *optee_ctx);
+void opteed_cpu_on_finish_handler(u_register_t unused);
 
 extern optee_context_t opteed_sp_context[OPTEED_CORE_COUNT];
 extern uint32_t opteed_rw;
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*/
diff --git a/services/spd/opteed/teesmc_opteed_macros.h b/services/spd/opteed/teesmc_opteed_macros.h
index 9d8a169..ad3ed75 100644
--- a/services/spd/opteed/teesmc_opteed_macros.h
+++ b/services/spd/opteed/teesmc_opteed_macros.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2014-2023, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -14,4 +14,10 @@
 		 (62 << FUNCID_OEN_SHIFT) | \
 		 ((func_num) & FUNCID_NUM_MASK))
 
+#define NSSMC_OPTEED_CALL(func_num) \
+		((SMC_TYPE_FAST << FUNCID_TYPE_SHIFT) | \
+		((SMC_32) << FUNCID_CC_SHIFT) | \
+		(50 << FUNCID_OEN_SHIFT) | \
+		((func_num) & FUNCID_NUM_MASK))
+
 #endif /* TEESMC_OPTEED_MACROS_H */