diff --git a/partitions/delegated_attestation/delegated_attest_req_mngr.c b/partitions/delegated_attestation/delegated_attest_req_mngr.c
index 8037bb4..4e1268b 100644
--- a/partitions/delegated_attestation/delegated_attest_req_mngr.c
+++ b/partitions/delegated_attestation/delegated_attest_req_mngr.c
@@ -125,51 +125,15 @@
     return status;
 }
 
-static void delegated_attestation_signal_handle(psa_signal_t signal)
+psa_status_t tfm_delegated_attestation_sfn(const psa_msg_t *msg)
 {
-    psa_status_t status;
-    psa_msg_t msg;
-
-    /* Retrieve the message corresponding to the
-     * Delegated Attestation service signal.
-     */
-    status = psa_get(signal, &msg);
-    if (status != PSA_SUCCESS) {
-        return;
-    }
-
-    switch (msg.type) {
+    switch (msg->type) {
     case DELEGATED_ATTEST_GET_DELEGATED_KEY:
-        status = get_delegated_attestation_key(&msg);
-        /* Reply with the message result status to unblock the client */
-        psa_reply(msg.handle, status);
-        break;
+        return get_delegated_attestation_key(msg);
     case DELEGATED_ATTEST_GET_PLATFORM_TOKEN:
-        status = get_platform_attestation_token(&msg);
-        /* Reply with the message result status to unblock the client */
-        psa_reply(msg.handle, status);
-        break;
+        return get_platform_attestation_token(msg);
     default:
         /* Invalid message type */
-        psa_panic();
-    }
-}
-
-void delegated_attest_partition_main(void)
-{
-    psa_signal_t signals = 0;
-
-    /* Delegated Attestation partition initialization.
-     * - Nothing to do -
-     */
-
-    while (1) {
-        signals = psa_wait(PSA_WAIT_ANY, PSA_BLOCK);
-        if (signals & TFM_DELEGATED_ATTESTATION_SIGNAL) {
-            delegated_attestation_signal_handle(TFM_DELEGATED_ATTESTATION_SIGNAL);
-        } else {
-            /* Should not come here */
-            psa_panic();
-        }
+        return PSA_ERROR_NOT_SUPPORTED;
     }
 }
diff --git a/partitions/delegated_attestation/tfm_delegated_attestation.yaml b/partitions/delegated_attestation/tfm_delegated_attestation.yaml
index 3d20bc6..2bbce90 100644
--- a/partitions/delegated_attestation/tfm_delegated_attestation.yaml
+++ b/partitions/delegated_attestation/tfm_delegated_attestation.yaml
@@ -10,8 +10,7 @@
   "name": "TFM_SP_DELEGATED_ATTESTATION",
   "type": "APPLICATION-ROT",
   "priority": "NORMAL",
-  "model": "IPC",
-  "entry_point": "delegated_attest_partition_main",
+  "model": "SFN",
   "stack_size": "0x0500",
   "services": [
     {
diff --git a/partitions/measured_boot/measured_boot_req_mngr.c b/partitions/measured_boot/measured_boot_req_mngr.c
index 8f27536..3a69d21 100644
--- a/partitions/measured_boot/measured_boot_req_mngr.c
+++ b/partitions/measured_boot/measured_boot_req_mngr.c
@@ -155,36 +155,6 @@
                                             extend_iov.lock_measurement);
 }
 
-static void measured_boot_signal_handle(psa_signal_t signal)
-{
-    psa_status_t status;
-    psa_msg_t msg;
-
-    /* Retrieve the message corresponding to the measured_boot service signal */
-    status = psa_get(signal, &msg);
-    if (status != PSA_SUCCESS) {
-        return;
-    }
-
-    /* Decode the message */
-    switch (msg.type) {
-    case TFM_MEASURED_BOOT_READ:
-        status = read_measurements(&msg);
-        /* Reply with the message result status to unblock the client */
-        psa_reply(msg.handle, status);
-        break;
-    case TFM_MEASURED_BOOT_EXTEND:
-        status = extend_measurement(&msg);
-        /* Reply with the message result status to unblock the client */
-        psa_reply(msg.handle, status);
-        break;
-    default:
-        /* Invalid message type */
-        status = PSA_ERROR_NOT_SUPPORTED;
-        break;
-    }
-}
-
 /**
  * \brief The measured_boot partition's entry function.
  */
@@ -202,18 +172,18 @@
     status = collect_shared_measurements();
 #endif
 
-    if (status != PSA_SUCCESS) {
-        psa_panic();
-    }
+    return status;
+}
 
-    psa_signal_t signals = 0;
-
-    while (1) {
-        signals = psa_wait(PSA_WAIT_ANY, PSA_BLOCK);
-        if (signals & TFM_MEASURED_BOOT_SIGNAL) {
-            measured_boot_signal_handle(TFM_MEASURED_BOOT_SIGNAL);
-        } else {
-            psa_panic();
-        }
+psa_status_t tfm_measured_boot_sfn(const psa_msg_t *msg)
+{
+    switch (msg->type) {
+    case TFM_MEASURED_BOOT_READ:
+        return read_measurements(msg);
+    case TFM_MEASURED_BOOT_EXTEND:
+        return extend_measurement(msg);
+    default:
+        /* Invalid message type */
+        return PSA_ERROR_NOT_SUPPORTED;
     }
 }
diff --git a/partitions/measured_boot/tfm_measured_boot.yaml b/partitions/measured_boot/tfm_measured_boot.yaml
index 17530fa..81a60f2 100644
--- a/partitions/measured_boot/tfm_measured_boot.yaml
+++ b/partitions/measured_boot/tfm_measured_boot.yaml
@@ -10,8 +10,8 @@
   "name": "TFM_SP_MEASURED_BOOT",
   "type": "PSA-ROT",
   "priority": "NORMAL",
-  "model": "IPC",
-  "entry_point": "tfm_measured_boot_init",
+  "model": "SFN",
+  "entry_init": "tfm_measured_boot_init",
   "stack_size": "0x400",
   "services": [
     {