diff --git a/secure_fw/spm/CMakeLists.txt b/secure_fw/spm/CMakeLists.txt
index aed3438..98e4d56 100755
--- a/secure_fw/spm/CMakeLists.txt
+++ b/secure_fw/spm/CMakeLists.txt
@@ -56,7 +56,7 @@
         $<$<BOOL:${CONFIG_TFM_STACK_WATERMARKS}>:ffm/stack_watermark.c>
         $<$<BOOL:${TFM_PSA_API}>:cmsis_psa/tfm_core_svcalls_ipc.c>
         $<$<BOOL:${TFM_PSA_API}>:cmsis_psa/tfm_pools.c>
-        $<$<BOOL:${TFM_PSA_API}>:cmsis_psa/thread.c>
+        $<$<BOOL:${CONFIG_TFM_SPM_BACKEND_IPC}>:cmsis_psa/thread.c>
         $<$<NOT:$<BOOL:${TFM_PSA_API}>>:cmsis_func/main.c>
         $<$<NOT:$<BOOL:${TFM_PSA_API}>>:cmsis_func/arch.c>
         $<$<NOT:$<BOOL:${TFM_PSA_API}>>:cmsis_func/spm_func.c>
diff --git a/secure_fw/spm/cmsis_psa/arch/tfm_arch.c b/secure_fw/spm/cmsis_psa/arch/tfm_arch.c
index e340181..d6688bd 100644
--- a/secure_fw/spm/cmsis_psa/arch/tfm_arch.c
+++ b/secure_fw/spm/cmsis_psa/arch/tfm_arch.c
@@ -9,6 +9,7 @@
 #include "security_defs.h"
 #include "tfm_arch.h"
 #include "utilities.h"
+#include "config_impl.h"
 
 __naked void tfm_arch_free_msp_and_exc_ret(uint32_t msp_base,
                                            uint32_t exc_return)
@@ -26,7 +27,7 @@
         "bx      r1                             \n"
     );
 }
-
+#if CONFIG_TFM_SPM_BACKEND_IPC == 1
 void tfm_arch_set_context_ret_code(void *p_ctx_ctrl, uint32_t ret_code)
 {
     struct context_ctrl_t *ctx_ctrl = (struct context_ctrl_t *)p_ctx_ctrl;
@@ -59,6 +60,7 @@
         "bx      lr                                    \n"
     );
 }
+#endif
 
 void tfm_arch_init_context(void *p_ctx_ctrl,
                            uintptr_t pfn, void *param, uintptr_t pfnlr)
diff --git a/secure_fw/spm/cmsis_psa/arch/tfm_arch_v6m_v7m.c b/secure_fw/spm/cmsis_psa/arch/tfm_arch_v6m_v7m.c
index 2b844ab..2f04b30 100644
--- a/secure_fw/spm/cmsis_psa/arch/tfm_arch_v6m_v7m.c
+++ b/secure_fw/spm/cmsis_psa/arch/tfm_arch_v6m_v7m.c
@@ -24,7 +24,7 @@
 /* IAR Specific */
 #if defined(__ICCARM__)
 
-#pragma required = do_schedule
+#pragma required = ipc_schedule
 #pragma required = scheduler_lock
 #pragma required = tfm_core_svc_handler
 
@@ -77,6 +77,7 @@
 
 #endif /* CONFIG_TFM_PSA_API_CROSS_CALL == 1*/
 
+#if CONFIG_TFM_SPM_BACKEND_IPC == 1
 __attribute__((naked)) void PendSV_Handler(void)
 {
     __ASM volatile(
@@ -84,7 +85,7 @@
         ".syntax unified                    \n"
 #endif
         "   push    {r0, lr}                \n"
-        "   bl      do_schedule             \n"
+        "   bl      ipc_schedule             \n"
         "   pop     {r2, r3}                \n"
         "   mov     lr, r3                  \n"
         "   cmp     r0, r1                  \n" /* ctx of curr and next thrd */
@@ -118,6 +119,7 @@
         "   bx      lr                      \n"
     );
 }
+#endif
 
 __attribute__((naked)) void SVC_Handler(void)
 {
diff --git a/secure_fw/spm/cmsis_psa/arch/tfm_arch_v8m_base.c b/secure_fw/spm/cmsis_psa/arch/tfm_arch_v8m_base.c
index 15fc098..dd61599 100644
--- a/secure_fw/spm/cmsis_psa/arch/tfm_arch_v8m_base.c
+++ b/secure_fw/spm/cmsis_psa/arch/tfm_arch_v8m_base.c
@@ -25,7 +25,7 @@
 /* IAR Specific */
 #if defined(__ICCARM__)
 
-#pragma required = do_schedule
+#pragma required = ipc_schedule
 #pragma required = scheduler_lock
 #pragma required = tfm_core_svc_handler
 
@@ -85,6 +85,7 @@
 
 #endif /* CONFIG_TFM_PSA_API_CROSS_CALL == 1 */
 
+#if CONFIG_TFM_SPM_BACKEND_IPC == 1
 __attribute__((naked)) void PendSV_Handler(void)
 {
     __ASM volatile(
@@ -96,7 +97,7 @@
         "   tst     r0, r1                              \n" /* NS interrupted */
         "   beq     v8b_pendsv_exit                     \n" /* No schedule */
         "   push    {r0, lr}                            \n" /* Save R0, LR */
-        "   bl      do_schedule                         \n"
+        "   bl      ipc_schedule                         \n"
         "   pop     {r2, r3}                            \n"
         "   mov     lr, r3                              \n"
         "   cmp     r0, r1                              \n" /* curr, next ctx */
@@ -132,6 +133,7 @@
         "   bx      lr                                  \n"
     );
 }
+#endif
 
 __attribute__((naked)) void SVC_Handler(void)
 {
diff --git a/secure_fw/spm/cmsis_psa/arch/tfm_arch_v8m_main.c b/secure_fw/spm/cmsis_psa/arch/tfm_arch_v8m_main.c
index 2398a81..aefcbe4 100644
--- a/secure_fw/spm/cmsis_psa/arch/tfm_arch_v8m_main.c
+++ b/secure_fw/spm/cmsis_psa/arch/tfm_arch_v8m_main.c
@@ -30,7 +30,7 @@
 /* IAR Specific */
 #if defined(__ICCARM__)
 
-#pragma required = do_schedule
+#pragma required = ipc_schedule
 #pragma required = scheduler_lock
 #pragma required = tfm_core_svc_handler
 
@@ -88,6 +88,7 @@
 
 #endif /* CONFIG_TFM_PSA_API_CROSS_CALL == 1*/
 
+#if CONFIG_TFM_SPM_BACKEND_IPC == 1
 __attribute__((naked)) void PendSV_Handler(void)
 {
     __ASM volatile(
@@ -98,7 +99,7 @@
         "   ands    r0, lr                              \n" /* NS interrupted */
         "   beq     v8m_pendsv_exit                     \n" /* No schedule */
         "   push    {r0, lr}                            \n" /* Save R0, LR */
-        "   bl      do_schedule                         \n"
+        "   bl      ipc_schedule                         \n"
         "   pop     {r2, lr}                            \n"
         "   cmp     r0, r1                              \n" /* curr, next ctx */
         "   beq     v8m_pendsv_exit                     \n" /* No schedule */
@@ -116,6 +117,7 @@
         "   bx      lr                                  \n"
     );
 }
+#endif
 
 #if defined(__ICCARM__)
 uint32_t tfm_core_svc_handler(uint32_t *msp, uint32_t exc_return,
diff --git a/secure_fw/spm/cmsis_psa/spm_ipc.c b/secure_fw/spm/cmsis_psa/spm_ipc.c
index f3f20b9..f83ba23 100755
--- a/secure_fw/spm/cmsis_psa/spm_ipc.c
+++ b/secure_fw/spm/cmsis_psa/spm_ipc.c
@@ -9,7 +9,6 @@
 #include <inttypes.h>
 #include <stdbool.h>
 #include <stdint.h>
-#include "aapcs_local.h"
 #include "bitops.h"
 #include "config_impl.h"
 #include "critical_section.h"
@@ -42,9 +41,6 @@
 #include "load/asset_defs.h"
 #include "load/spm_load_api.h"
 #include "tfm_nspm.h"
-#if defined(CONFIG_TFM_PARTITION_META)
-#include "tfm_hal_memory_symbols.h"
-#endif
 
 #if !(defined CONFIG_TFM_CONN_HANDLE_MAX_NUM) || (CONFIG_TFM_CONN_HANDLE_MAX_NUM == 0)
 #error "CONFIG_TFM_CONN_HANDLE_MAX_NUM must be defined and not zero."
@@ -54,17 +50,10 @@
 static struct service_head_t services_listhead;
 struct service_t *stateless_services_ref_tbl[STATIC_HANDLE_NUM_LIMIT];
 
-#if defined(CONFIG_TFM_PARTITION_META)
-/* Indicator point to the partition meta */
-static uintptr_t *partition_meta_indicator_pos = NULL;
-#endif
-
 /* Pools */
 TFM_POOL_DECLARE(conn_handle_pool, sizeof(struct conn_handle_t),
                  CONFIG_TFM_CONN_HANDLE_MAX_NUM);
 
-extern uint32_t scheduler_lock;
-
 /*********************** Connection handle conversion APIs *******************/
 
 #define CONVERSION_FACTOR_BITOFFSET    3
@@ -563,66 +552,9 @@
         backend_instance.comp_init_assuredly(partition, service_setting);
     }
 
-#if defined(CONFIG_TFM_PARTITION_META)
-    partition_meta_indicator_pos = (uintptr_t *)hal_mem_sp_meta_start;
-#endif
-
     return backend_instance.system_run();
 }
 
-uint64_t do_schedule(void)
-{
-    AAPCS_DUAL_U32_T ctx_ctrls;
-    struct partition_t *p_part_curr, *p_part_next;
-    struct context_ctrl_t *p_curr_ctx;
-    struct thread_t *pth_next = thrd_next();
-    struct critical_section_t cs = CRITICAL_SECTION_STATIC_INIT;
-
-    p_curr_ctx = (struct context_ctrl_t *)(CURRENT_THREAD->p_context_ctrl);
-
-    AAPCS_DUAL_U32_SET(ctx_ctrls, (uint32_t)p_curr_ctx, (uint32_t)p_curr_ctx);
-
-    p_part_curr = GET_CURRENT_COMPONENT();
-    p_part_next = GET_THRD_OWNER(pth_next);
-
-    if (scheduler_lock != SCHEDULER_LOCKED && pth_next != NULL &&
-        p_part_curr != p_part_next) {
-        /* Check if there is enough room on stack to save more context */
-        if ((p_curr_ctx->sp_limit +
-                sizeof(struct tfm_additional_context_t)) > __get_PSP()) {
-            tfm_core_panic();
-        }
-
-        CRITICAL_SECTION_ENTER(cs);
-        /*
-         * If required, let the platform update boundary based on its
-         * implementation. Change privilege, MPU or other configurations.
-         */
-        if (p_part_curr->p_boundaries != p_part_next->p_boundaries) {
-            if (tfm_hal_update_boundaries(p_part_next->p_ldinf,
-                                          p_part_next->p_boundaries)
-                                                        != TFM_HAL_SUCCESS) {
-                tfm_core_panic();
-            }
-        }
-        ARCH_FLUSH_FP_CONTEXT();
-
-        AAPCS_DUAL_U32_SET_A1(ctx_ctrls, (uint32_t)pth_next->p_context_ctrl);
-
-        CURRENT_THREAD = pth_next;
-        CRITICAL_SECTION_LEAVE(cs);
-    }
-
-#if defined(CONFIG_TFM_PARTITION_META)
-    /* Update meta indicator */
-    if (partition_meta_indicator_pos && (p_part_next->p_metadata)) {
-        *partition_meta_indicator_pos = (uintptr_t)(p_part_next->p_metadata);
-    }
-#endif
-
-    return AAPCS_DUAL_U32_AS_U64(ctx_ctrls);
-}
-
 void update_caller_outvec_len(struct conn_handle_t *handle)
 {
     uint32_t i;
diff --git a/secure_fw/spm/cmsis_psa/spm_ipc.h b/secure_fw/spm/cmsis_psa/spm_ipc.h
index 88ebc3e..d8b6d70 100644
--- a/secure_fw/spm/cmsis_psa/spm_ipc.h
+++ b/secure_fw/spm/cmsis_psa/spm_ipc.h
@@ -118,15 +118,16 @@
     void                               *p_boundaries;
     void                               *p_interrupts;
     void                               *p_metadata;
-    struct context_ctrl_t              ctx_ctrl;
     uint32_t                           signals_allowed;
     uint32_t                           signals_waiting;
     volatile uint32_t                  signals_asserted;
+#if CONFIG_TFM_SPM_BACKEND_IPC == 1
+    struct context_ctrl_t              ctx_ctrl;
     struct sync_obj_t                  waitobj;
-    union {
-        struct thread_t                thrd;            /* IPC model */
-        uint32_t                       state;           /* SFN model */
-    };
+    struct thread_t                    thrd;            /* IPC model */
+#else
+    uint32_t                           state;           /* SFN model */
+#endif
     struct conn_handle_t               *p_handles;
     struct partition_t                 *next;
 };
@@ -357,7 +358,7 @@
  *  Each takes 32 bits. The context control is used by PendSV_Handler to do
  *  context switch.
  */
-uint64_t do_schedule(void);
+uint64_t ipc_schedule(void);
 
 /**
  * \brief                      SPM initialization implementation
diff --git a/secure_fw/spm/cmsis_psa/tfm_core_svcalls_ipc.c b/secure_fw/spm/cmsis_psa/tfm_core_svcalls_ipc.c
index cbcc65e..8ee8621 100644
--- a/secure_fw/spm/cmsis_psa/tfm_core_svcalls_ipc.c
+++ b/secure_fw/spm/cmsis_psa/tfm_core_svcalls_ipc.c
@@ -32,6 +32,7 @@
                                      uint32_t *ctx, uint32_t lr);
 #endif
 
+#if CONFIG_TFM_SPM_BACKEND_IPC == 1
 static int32_t SVC_Handler_IPC(uint8_t svc_num, uint32_t *ctx,
                                uint32_t lr)
 {
@@ -129,6 +130,7 @@
     spm_handle_programmer_errors(status);
     return status;
 }
+#endif
 
 uint32_t tfm_core_svc_handler(uint32_t *msp, uint32_t exc_return,
                               uint32_t *psp)
@@ -187,17 +189,25 @@
         break;
 #endif
     default:
+#if CONFIG_TFM_SPM_BACKEND_IPC == 1
         if (((uint32_t)&REGION_NAME(Image$$, ARM_LIB_STACK, $$ZI$$Limit)
                                      - (uint32_t)msp) > TFM_STACK_SEALED_SIZE) {
             /* The Main Stack has contents, not calling from Partition thread */
             tfm_core_panic();
         }
         svc_args[0] = SVC_Handler_IPC(svc_number, svc_args, exc_return);
-
         if (THRD_EXPECTING_SCHEDULE()) {
             tfm_arch_trigger_pendsv();
         }
-
+#else
+#ifdef PLATFORM_SVC_HANDLERS
+        svc_args[0] = (platform_svc_handlers(svc_number, svc_args, exc_return));
+#else
+        SPMLOG_ERRMSG("Unknown SVC number requested!\r\n");
+        svc_args[0] = PSA_ERROR_GENERIC_ERROR;
+#endif
+        spm_handle_programmer_errors(svc_args[0]);
+#endif
         break;
     }
 
diff --git a/secure_fw/spm/ffm/backend_ipc.c b/secure_fw/spm/ffm/backend_ipc.c
index 597016d..515af61 100644
--- a/secure_fw/spm/ffm/backend_ipc.c
+++ b/secure_fw/spm/ffm/backend_ipc.c
@@ -7,11 +7,13 @@
  */
 
 #include <stdint.h>
+#include "aapcs_local.h"
 #include "critical_section.h"
 #include "compiler_ext_defs.h"
 #include "runtime_defs.h"
 #include "ffm/stack_watermark.h"
 #include "spm_ipc.h"
+#include "tfm_hal_memory_symbols.h"
 #include "tfm_hal_isolation.h"
 #include "tfm_hal_platform.h"
 #include "tfm_rpc.h"
@@ -43,6 +45,11 @@
 
 #endif
 
+/* Indicator point to the partition meta */
+uintptr_t *partition_meta_indicator_pos;
+
+extern uint32_t scheduler_lock;
+
 static void prv_process_metadata(struct partition_t *p_pt)
 {
     const struct partition_load_info_t *p_pt_ldi;
@@ -194,6 +201,7 @@
     TFM_CORE_ASSERT(SPM_THREAD_CONTEXT);
 #endif
 
+    partition_meta_indicator_pos = (uintptr_t *)hal_mem_sp_meta_start;
     control = thrd_start_scheduler(&CURRENT_THREAD);
 
     p_cur_pt = TO_CONTAINER(CURRENT_THREAD->p_context_ctrl,
@@ -238,6 +246,56 @@
     p_pt->signals_waiting = 0;
 }
 
+uint64_t ipc_schedule(void)
+{
+    AAPCS_DUAL_U32_T ctx_ctrls;
+    struct partition_t *p_part_curr, *p_part_next;
+    struct context_ctrl_t *p_curr_ctx;
+    struct thread_t *pth_next = thrd_next();
+    struct critical_section_t cs = CRITICAL_SECTION_STATIC_INIT;
+
+    p_curr_ctx = (struct context_ctrl_t *)(CURRENT_THREAD->p_context_ctrl);
+
+    AAPCS_DUAL_U32_SET(ctx_ctrls, (uint32_t)p_curr_ctx, (uint32_t)p_curr_ctx);
+
+    p_part_curr = GET_CURRENT_COMPONENT();
+    p_part_next = GET_THRD_OWNER(pth_next);
+
+    if (scheduler_lock != SCHEDULER_LOCKED && pth_next != NULL &&
+        p_part_curr != p_part_next) {
+        /* Check if there is enough room on stack to save more context */
+        if ((p_curr_ctx->sp_limit +
+                sizeof(struct tfm_additional_context_t)) > __get_PSP()) {
+            tfm_core_panic();
+        }
+
+        CRITICAL_SECTION_ENTER(cs);
+        /*
+         * If required, let the platform update boundary based on its
+         * implementation. Change privilege, MPU or other configurations.
+         */
+        if (p_part_curr->p_boundaries != p_part_next->p_boundaries) {
+            if (tfm_hal_update_boundaries(p_part_next->p_ldinf,
+                                          p_part_next->p_boundaries)
+                                                        != TFM_HAL_SUCCESS) {
+                tfm_core_panic();
+            }
+        }
+        ARCH_FLUSH_FP_CONTEXT();
+
+        AAPCS_DUAL_U32_SET_A1(ctx_ctrls, (uint32_t)pth_next->p_context_ctrl);
+
+        CURRENT_THREAD = pth_next;
+        CRITICAL_SECTION_LEAVE(cs);
+    }
+
+    /* Update meta indicator */
+    if (partition_meta_indicator_pos && (p_part_next->p_metadata)) {
+        *partition_meta_indicator_pos = (uintptr_t)(p_part_next->p_metadata);
+    }
+    return AAPCS_DUAL_U32_AS_U64(ctx_ctrls);
+}
+
 const struct backend_ops_t backend_instance = {
     .comp_init_assuredly = ipc_comp_init_assuredly,
     .system_run          = ipc_system_run,
diff --git a/secure_fw/spm/ffm/backend_sfn.c b/secure_fw/spm/ffm/backend_sfn.c
index 9218afc..eae5d16 100644
--- a/secure_fw/spm/ffm/backend_sfn.c
+++ b/secure_fw/spm/ffm/backend_sfn.c
@@ -27,6 +27,9 @@
 /* Declare the global component list */
 struct partition_head_t partition_listhead;
 
+/* Current running partition. */
+struct partition_t *p_current_partition;
+
 /*
  * Send message and wake up the SP who is waiting on message queue, block the
  * current component state and activate the next component.
@@ -115,16 +118,10 @@
 void sfn_comp_init_assuredly(struct partition_t *p_pt, uint32_t service_set)
 {
     const struct partition_load_info_t *p_pldi = p_pt->p_ldinf;
-
+    struct context_ctrl_t ns_agent_ctrl;
     p_pt->p_handles = NULL;
     p_pt->state = SFN_PARTITION_STATE_NOT_INITED;
 
-    THRD_SYNC_INIT(&p_pt->waitobj);
-
-    ARCH_CTXCTRL_INIT(&p_pt->ctx_ctrl,
-                      LOAD_ALLOCED_STACK_ADDR(p_pldi),
-                      p_pldi->stack_size);
-
     watermark_stack(p_pt);
 
     /*
@@ -132,18 +129,19 @@
      * IDLE partition, and NS Agent (TZ) needs to be specific cared here.
      */
     if (p_pldi->pid == TFM_SP_NON_SECURE_ID) {
-        THRD_INIT(&p_pt->thrd, &p_pt->ctx_ctrl,
-                  TO_THREAD_PRIORITY(PARTITION_PRIORITY(p_pldi->flags)));
-
-        thrd_start(&p_pt->thrd,
-                   POSITION_TO_ENTRY(spm_thread_fn, thrd_fn_t),
-                   POSITION_TO_ENTRY(p_pldi->entry, thrd_fn_t));
+        ARCH_CTXCTRL_INIT(&ns_agent_ctrl,
+                          LOAD_ALLOCED_STACK_ADDR(p_pldi),
+                          p_pldi->stack_size);
+        tfm_arch_init_context(&ns_agent_ctrl, (uintptr_t)spm_thread_fn,
+                              NULL, p_pldi->entry);
+        tfm_arch_refresh_hardware_context(&ns_agent_ctrl);
+        SET_CURRENT_COMPONENT(p_pt);
     }
 }
 
 uint32_t sfn_system_run(void)
 {
-    return thrd_start_scheduler(&CURRENT_THREAD);
+    return EXC_RETURN_THREAD_S_PSP;
 }
 
 static psa_signal_t sfn_wait(struct partition_t *p_pt, psa_signal_t signal_mask)
diff --git a/secure_fw/spm/ffm/interrupt.c b/secure_fw/spm/ffm/interrupt.c
index 99d796e..1b34e04 100644
--- a/secure_fw/spm/ffm/interrupt.c
+++ b/secure_fw/spm/ffm/interrupt.c
@@ -165,9 +165,11 @@
 
     if (flih_result == PSA_FLIH_SIGNAL) {
         spm_assert_signal(p_pt, p_ildi->signal);
-
+        /* In SFN backend, there is only one thread, no thread switch. */
+#if CONFIG_TFM_SPM_BACKEND_SFN != 1
         if (THRD_EXPECTING_SCHEDULE()) {
             tfm_arch_trigger_pendsv();
         }
+#endif
     }
 }
diff --git a/secure_fw/spm/include/current.h b/secure_fw/spm/include/current.h
index e69473d..63a25bd 100644
--- a/secure_fw/spm/include/current.h
+++ b/secure_fw/spm/include/current.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021, Arm Limited. All rights reserved.
+ * Copyright (c) 2021-2022, Arm Limited. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  *
@@ -10,9 +10,17 @@
 #include "thread.h"
 #include "spm_ipc.h"
 
+#if CONFIG_TFM_SPM_BACKEND_SFN != 1
 /* Get current component */
 #define GET_CURRENT_COMPONENT()  GET_CTX_OWNER(CURRENT_THREAD->p_context_ctrl)
 /* Set current component */
 #define SET_CURRENT_COMPONENT(p) THRD_UPDATE_CUR_CTXCTRL(&(p)->ctx_ctrl)
+#else
+extern struct partition_t *p_current_partition;
+/* Get current component */
+#define GET_CURRENT_COMPONENT()  p_current_partition
+/* Set current component */
+#define SET_CURRENT_COMPONENT(p) p_current_partition = p
+#endif
 
 #endif /* __CURRENT_H__ */