Changes required for SW-defined IO devices on L15

arch/riscv/core/thread.c

@@ -212,6 +212,8 @@ FUNC_NORETURN void z_riscv_switch_to_main_no_multithreading(k_thread_entry_t mai
 	main_stack = (K_THREAD_STACK_BUFFER(z_main_stack) +
 		      K_THREAD_STACK_SIZEOF(z_main_stack));
 
+	irq_unlock(MSTATUS_IEN);
+
 	__asm__ volatile (
 	"mv sp, %0; jalr ra, %1, 0"
 	:

include/zephyr/ipc/icmsg.h

@@ -51,8 +51,10 @@ struct icmsg_data_t {
 
 	/* General */
 	const struct icmsg_config_t *cfg;
+#ifdef CONFIG_MULTITHREADING
 	struct k_work_delayable notify_work;
 	struct k_work mbox_work;
+#endif
 	atomic_t state;
 };
 

samples/drivers/mbox/remote/src/main.c

@@ -51,17 +51,20 @@ int main(void)
 	printk("Maximum TX channels: %d\n", mbox_max_channels_get_dt(&tx_channel));
 
 	while (1) {
+#if defined(CONFIG_MULTITHREADING)
+		k_sleep(K_MSEC(3000));
+#else
+		k_busy_wait(3000000);
+#endif
+
 		printk("Ping (on channel %d)\n", tx_channel.channel_id);
 
 		ret = mbox_send_dt(&tx_channel, NULL);
 		if (ret < 0) {
 			printk("Could not send (%d)\n", ret);
 			return 0;
 		}
-
-		k_sleep(K_MSEC(3000));
 	}
 #endif /* CONFIG_TX_ENABLED */
-
 	return 0;
 }

samples/drivers/mbox/sample.yaml

@@ -82,3 +82,38 @@ tests:
       regex:
         - "Ping \\(on channel 16\\)"
         - "Pong \\(on channel 15\\)"
+
+  sample.drivers.mbox.nrf54l15_no_multithreading:
+    platform_allow:
+      - nrf54l15pdk/nrf54l15/cpuapp
+    integration_platforms:
+      - nrf54l15pdk/nrf54l15/cpuapp
+    extra_args:
+      mbox_SNIPPET=nordic-flpr
+      mbox_CONFIG_MULTITHREADING=n
+      remote_CONFIG_MULTITHREADING=n
+    sysbuild: true
+    harness: console
+    harness_config:
+      type: multi_line
+      ordered: false
+      regex:
+        - "Ping \\(on channel 16\\)"
+        - "Pong \\(on channel 15\\)"
+
+  sample.drivers.mbox.nrf54l15_remote_no_multithreading:
+    platform_allow:
+      - nrf54l15pdk/nrf54l15/cpuapp
+    integration_platforms:
+      - nrf54l15pdk/nrf54l15/cpuapp
+    extra_args:
+      mbox_SNIPPET=nordic-flpr
+      remote_CONFIG_MULTITHREADING=n
+    sysbuild: true
+    harness: console
+    harness_config:
+      type: multi_line
+      ordered: false
+      regex:
+        - "Ping \\(on channel 16\\)"
+        - "Pong \\(on channel 15\\)"

samples/drivers/mbox/src/main.c

@@ -47,7 +47,11 @@ int main(void)
 	printk("Maximum TX channels: %d\n", mbox_max_channels_get_dt(&tx_channel));
 
 	while (1) {
+#if defined(CONFIG_MULTITHREADING)
 		k_sleep(K_MSEC(2000));
+#else
+		k_busy_wait(2000000);
+#endif
 
 		printk("Ping (on channel %d)\n", tx_channel.channel_id);
 

samples/subsys/ipc/ipc_service/icmsg/remote/boards/nrf54l15pdk_nrf54l15_cpuflpr.overlay

@@ -39,3 +39,7 @@
 &cpuflpr_vevif_tx {
 	status = "okay";
 };
+
+&uart30 {
+	/delete-property/ hw-flow-control;
+};

samples/subsys/ipc/ipc_service/icmsg/remote/src/main.c

@@ -14,26 +14,44 @@
 #include <zephyr/logging/log.h>
 LOG_MODULE_REGISTER(remote, LOG_LEVEL_INF);
 
-
+#if defined(CONFIG_MULTITHREADING)
 K_SEM_DEFINE(bound_sem, 0, 1);
+#else
+volatile uint32_t bound_sem = 1;
+volatile uint32_t recv_sem = 1;
+#endif
+
+static unsigned char expected_message = 'a';
+static size_t expected_len = PACKET_SIZE_START;
+static size_t received;
 
 static void ep_bound(void *priv)
 {
+	received = 0;
+#if defined(CONFIG_MULTITHREADING)
 	k_sem_give(&bound_sem);
+#else
+	bound_sem = 0;
+#endif
 	LOG_INF("Ep bounded");
 }
 
 static void ep_recv(const void *data, size_t len, void *priv)
 {
+#if defined(CONFIG_ASSERT)
 	struct data_packet *packet = (struct data_packet *)data;
-	static unsigned char expected_message = 'a';
-	static size_t expected_len = PACKET_SIZE_START;
 
 	__ASSERT(packet->data[0] == expected_message, "Unexpected message. Expected %c, got %c",
 		expected_message, packet->data[0]);
 	__ASSERT(len == expected_len, "Unexpected length. Expected %zu, got %zu",
 		expected_len, len);
+#endif
+
+#ifndef CONFIG_MULTITHREADING
+	recv_sem = 0;
+#endif
 
+	received += len;
 	expected_message++;
 	expected_len++;
 
@@ -61,11 +79,17 @@ static int send_for_time(struct ipc_ept *ep, const int64_t sending_time_ms)
 		ret = ipc_service_send(ep, &msg, mlen);
 		if (ret == -ENOMEM) {
 			/* No space in the buffer. Retry. */
+			ret = 0;
 			continue;
 		} else if (ret < 0) {
 			LOG_ERR("Failed to send (%c) failed with ret %d", msg.data[0], ret);
 			break;
 		}
+#if !defined(CONFIG_MULTITHREADING)
+		else {
+			recv_sem = 1;
+		}
+#endif
 
 		msg.data[0]++;
 		if (msg.data[0] > 'Z') {
@@ -79,7 +103,12 @@ static int send_for_time(struct ipc_ept *ep, const int64_t sending_time_ms)
 			mlen = PACKET_SIZE_START;
 		}
 
+#if defined(CONFIG_MULTITHREADING)
 		k_usleep(1);
+#else
+		while ((recv_sem != 0) && ((k_uptime_get() - start) < sending_time_ms)) {
+		};
+#endif
 	}
 
 	LOG_INF("Sent %zu [Bytes] over %lld [ms]", bytes_sent, sending_time_ms);
@@ -111,19 +140,25 @@ int main(void)
 	}
 
 	ret = ipc_service_register_endpoint(ipc0_instance, &ep, &ep_cfg);
-	if (ret != 0) {
+	if (ret < 0) {
 		LOG_ERR("ipc_service_register_endpoint() failure");
 		return ret;
 	}
 
+#if defined(CONFIG_MULTITHREADING)
 	k_sem_take(&bound_sem, K_FOREVER);
+#else
+	while (bound_sem != 0) {
+	};
+#endif
 
 	ret = send_for_time(&ep, SENDING_TIME_MS);
 	if (ret < 0) {
 		LOG_ERR("send_for_time() failure");
 		return ret;
 	}
 
+	LOG_INF("Received %zu [Bytes] in total", received);
 	LOG_INF("IPC-service REMOTE demo ended");
 
 	return 0;

samples/subsys/ipc/ipc_service/icmsg/sample.yaml

@@ -18,6 +18,7 @@ tests:
         - "host: Sent"
         - "host: Received"
         - "host: IPC-service HOST demo ended"
+
   sample.ipc.icmsg.nrf54l15:
     platform_allow: nrf54l15pdk/nrf54l15/cpuapp
     integration_platforms:
@@ -26,4 +27,60 @@ tests:
     extra_args:
       icmsg_SNIPPET=nordic-flpr
     sysbuild: true
-    harness: remote
+    harness: console
+    harness_config:
+      type: multi_line
+      ordered: false
+      regex:
+        - "host: IPC-service HOST demo started"
+        - "host: Ep bounded"
+        - "host: Perform sends for"
+        - "host: Sent"
+        - "host: Received"
+        - "host: IPC-service HOST demo ended"
+
+  sample.ipc.icmsg.nrf54l15_no_multithreading:
+    platform_allow: nrf54l15pdk/nrf54l15/cpuapp
+    integration_platforms:
+      - nrf54l15pdk/nrf54l15/cpuapp
+    tags: ipc
+    extra_args:
+      icmsg_SNIPPET=nordic-flpr
+      icmsg_CONFIG_MULTITHREADING=n
+      icmsg_CONFIG_LOG_MODE_MINIMAL=y
+      remote_CONFIG_MULTITHREADING=n
+      remote_CONFIG_LOG_MODE_MINIMAL=y
+    sysbuild: true
+    harness: console
+    harness_config:
+      type: multi_line
+      ordered: false
+      regex:
+        - "I: IPC-service HOST demo started"
+        - "I: Ep bounded"
+        - "I: Perform sends for"
+        - "I: Sent"
+        - "I: Received"
+        - "I: IPC-service HOST demo ended"
+
+  sample.ipc.icmsg.nrf54l15_remote_no_multithreading:
+    platform_allow: nrf54l15pdk/nrf54l15/cpuapp
+    integration_platforms:
+      - nrf54l15pdk/nrf54l15/cpuapp
+    tags: ipc
+    extra_args:
+      icmsg_SNIPPET=nordic-flpr
+      remote_CONFIG_MULTITHREADING=n
+      remote_CONFIG_LOG_MODE_MINIMAL=y
+    sysbuild: true
+    harness: console
+    harness_config:
+      type: multi_line
+      ordered: false
+      regex:
+        - "host: IPC-service HOST demo started"
+        - "host: Ep bounded"
+        - "host: Perform sends for"
+        - "host: Sent"
+        - "host: Received"
+        - "host: IPC-service HOST demo ended"

samples/subsys/ipc/ipc_service/icmsg/src/main.c

@@ -18,26 +18,44 @@
 #include <zephyr/logging/log.h>
 LOG_MODULE_REGISTER(host, LOG_LEVEL_INF);
 
-
+#if defined(CONFIG_MULTITHREADING)
 K_SEM_DEFINE(bound_sem, 0, 1);
+#else
+volatile uint32_t bound_sem = 1;
+volatile uint32_t recv_sem = 1;
+#endif
+
 static unsigned char expected_message = 'A';
 static size_t expected_len = PACKET_SIZE_START;
+static size_t received;
 
 static void ep_bound(void *priv)
 {
+	received = 0;
+#if defined(CONFIG_MULTITHREADING)
 	k_sem_give(&bound_sem);
+#else
+	bound_sem = 0;
+#endif
 	LOG_INF("Ep bounded");
 }
 
 static void ep_recv(const void *data, size_t len, void *priv)
 {
+#if defined(CONFIG_ASSERT)
 	struct data_packet *packet = (struct data_packet *)data;
 
 	__ASSERT(packet->data[0] == expected_message, "Unexpected message. Expected %c, got %c",
 		expected_message, packet->data[0]);
 	__ASSERT(len == expected_len, "Unexpected length. Expected %zu, got %zu",
 		expected_len, len);
+#endif
+
+#ifndef CONFIG_MULTITHREADING
+	recv_sem = 0;
+#endif
 
+	received += len;
 	expected_message++;
 	expected_len++;
 
@@ -70,6 +88,11 @@ static int send_for_time(struct ipc_ept *ep, const int64_t sending_time_ms)
 			LOG_ERR("Failed to send (%c) failed with ret %d", msg.data[0], ret);
 			break;
 		}
+#if !defined(CONFIG_MULTITHREADING)
+		else {
+			recv_sem = 1;
+		}
+#endif
 
 		msg.data[0]++;
 		if (msg.data[0] > 'z') {
@@ -83,7 +106,12 @@ static int send_for_time(struct ipc_ept *ep, const int64_t sending_time_ms)
 			mlen = PACKET_SIZE_START;
 		}
 
+#if defined(CONFIG_MULTITHREADING)
 		k_usleep(1);
+#else
+		while ((recv_sem != 0) && ((k_uptime_get() - start) < sending_time_ms)) {
+		};
+#endif
 	}
 
 	LOG_INF("Sent %zu [Bytes] over %lld [ms]", bytes_sent, sending_time_ms);
@@ -120,7 +148,12 @@ int main(void)
 		return ret;
 	}
 
+#if defined(CONFIG_MULTITHREADING)
 	k_sem_take(&bound_sem, K_FOREVER);
+#else
+	while (bound_sem != 0) {
+	};
+#endif
 
 	ret = send_for_time(&ep, SENDING_TIME_MS);
 	if (ret < 0) {
@@ -129,7 +162,13 @@ int main(void)
 	}
 
 	LOG_INF("Wait 500ms. Let remote core finish its sends");
+#if defined(CONFIG_MULTITHREADING)
 	k_msleep(500);
+#else
+	k_busy_wait(500000);
+#endif
+
+	LOG_INF("Received %zu [Bytes] in total", received);
 
 #if defined(CONFIG_SOC_NRF5340_CPUAPP)
 	LOG_INF("Stop network core");

subsys/ipc/ipc_service/lib/Kconfig.icmsg

@@ -3,6 +3,7 @@
 
 config IPC_SERVICE_ICMSG_SHMEM_ACCESS_SYNC
 	bool "Synchronize access to shared memory"
+	depends on MULTITHREADING
 	default y
 	help
 	  Provide synchronization access to shared memory at a library level.
@@ -30,6 +31,7 @@ config IPC_SERVICE_ICMSG_BOND_NOTIFY_REPEAT_TO_MS
 
 config IPC_SERVICE_BACKEND_ICMSG_WQ_ENABLE
 	bool "Use dedicated workqueue"
+	depends on MULTITHREADING
 	default y
 	help
 	  Enable dedicated workqueue thread for the ICMsg backend.