lib: csp: add FINCH CSP integration layer

apps/obc/prj.conf

@@ -3,6 +3,9 @@
 CONFIG_LOG=y
 CONFIG_LOG_DEFAULT_LEVEL=3
 CONFIG_COMPILER_WARNINGS_AS_ERRORS=y
+CONFIG_FINCH_CSP=y
+CONFIG_FINCH_CSP_NODE_ADDRESS=1
+CONFIG_FINCH_CSP_HOSTNAME="obc"
 
 # Configure UART as logging backend
 CONFIG_GPIO=y

apps/obc/src/main.c

@@ -4,13 +4,21 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
+#include <finch/csp/csp.h>
 #include <zephyr/kernel.h>
 #include <zephyr/logging/log.h>
 
 LOG_MODULE_REGISTER(obc);
 
 int main(void)
 {
+	int ret = finch_csp_init();
+
+	if (ret < 0) {
+		LOG_ERR("Failed to initialize FINCH CSP (%d)", ret);
+		return ret;
+	}
+
 	while (1) {
 		LOG_INF("obc");
 		k_msleep(1000);

apps/pay/prj.conf

@@ -3,6 +3,9 @@
 CONFIG_LOG=y
 CONFIG_LOG_DEFAULT_LEVEL=3
 CONFIG_COMPILER_WARNINGS_AS_ERRORS=y
+CONFIG_FINCH_CSP=y
+CONFIG_FINCH_CSP_NODE_ADDRESS=2
+CONFIG_FINCH_CSP_HOSTNAME="pay"
 
 # Configure UART as logging backend
 CONFIG_GPIO=y

apps/pay/src/main.c

@@ -4,13 +4,21 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
+#include <finch/csp/csp.h>
 #include <zephyr/kernel.h>
 #include <zephyr/logging/log.h>
 
 LOG_MODULE_REGISTER(pay);
 
 int main(void)
 {
+	int ret = finch_csp_init();
+
+	if (ret < 0) {
+		LOG_ERR("Failed to initialize FINCH CSP (%d)", ret);
+		return ret;
+	}
+
 	while (1) {
 		LOG_INF("pay");
 		k_msleep(1000);

include/finch/csp/csp.h

@@ -0,0 +1,12 @@
+/*
+ * Copyright (c) 2026 The FINCH CubeSat Project Flight Software Contributors
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef FINCH_CSP_CSP_H_
+#define FINCH_CSP_CSP_H_
+
+int finch_csp_init(void);
+
+#endif /* FINCH_CSP_CSP_H_ */

lib/CMakeLists.txt

@@ -2,3 +2,4 @@
 # SPDX-License-Identifier: Apache-2.0
 
 add_subdirectory_ifdef(CONFIG_FINCH_CCSDS123B ccsds123b)
+add_subdirectory_ifdef(CONFIG_FINCH_CSP csp)

lib/Kconfig

@@ -4,5 +4,6 @@
 menu "FINCH CubeSat Flight Software Libraries"
 
 rsource "ccsds123b/Kconfig"
+rsource "csp/Kconfig"
 
 endmenu

lib/csp/CMakeLists.txt

@@ -0,0 +1,6 @@
+# Copyright (c) 2026 The FINCH CubeSat Project Flight Software Contributors
+# SPDX-License-Identifier: Apache-2.0
+
+zephyr_library()
+zephyr_library_sources(src/core.c)
+zephyr_library_link_libraries(csp)

lib/csp/Kconfig

@@ -0,0 +1,50 @@
+# Copyright (c) 2026 The FINCH CubeSat Project Flight Software Contributors
+# SPDX-License-Identifier: Apache-2.0
+
+config FINCH_CSP
+	bool "Enable FINCH CSP integration"
+	select LIBCSP
+	help
+	  Build the FINCH libcsp integration layer.
+
+if FINCH_CSP
+
+config FINCH_CSP_NODE_ADDRESS
+	int "CSP node address"
+	range 0 16382
+	default 1
+	help
+	  CSP address used for this image.
+	  16383 is reserved as the CSP broadcast address.
+
+config FINCH_CSP_HOSTNAME
+	string "CSP hostname"
+	default "finch"
+	help
+	  Hostname exposed via CSP management services.
+
+config FINCH_CSP_MODEL
+	string "CSP model"
+	default "finch-flight-software"
+	help
+	  Model string exposed via CSP management services.
+
+config FINCH_CSP_REVISION
+	string "CSP revision"
+	default "dev"
+	help
+	  Revision string exposed via CSP management services.
+
+config FINCH_CSP_ROUTER_STACK_SIZE
+	int "CSP router thread stack size"
+	default 1024
+	help
+	  Stack size for the CSP router thread.
+
+config FINCH_CSP_ROUTER_PRIORITY
+	int "CSP router thread priority"
+	default 0
+	help
+	  Zephyr thread priority for the CSP router thread.
+
+endif # FINCH_CSP

lib/csp/src/core.c

@@ -0,0 +1,119 @@
+/*
+ * Copyright (c) 2026 The FINCH CubeSat Project Flight Software Contributors
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <errno.h>
+#include <stdbool.h>
+
+#include <csp/csp.h>
+#include <csp/interfaces/csp_if_lo.h>
+#include <finch/csp/csp.h>
+#include <zephyr/kernel.h>
+#include <zephyr/logging/log.h>
+
+LOG_MODULE_REGISTER(finch_csp);
+
+K_THREAD_STACK_DEFINE(finch_csp_router_stack, CONFIG_FINCH_CSP_ROUTER_STACK_SIZE);
+static struct k_thread finch_csp_router_thread_data;
+static k_tid_t finch_csp_router_tid;
+static K_MUTEX_DEFINE(finch_csp_lock);
+static bool finch_csp_initialized;
+
+static void finch_csp_router_thread(void *arg1, void *arg2, void *arg3)
+{
+	ARG_UNUSED(arg1);
+	ARG_UNUSED(arg2);
+	ARG_UNUSED(arg3);
+
+	while (1) {
+		(void)csp_route_work();
+	}
+}
+
+static int finch_csp_bind_service(uint8_t port)
+{
+	int ret = csp_bind_callback(csp_service_handler, port);
+
+	if ((ret == CSP_ERR_NONE) || (ret == CSP_ERR_USED) ||
+	    (ret == CSP_ERR_ALREADY)) {
+		return 0;
+	}
+
+	LOG_ERR("Failed to bind CSP service port %u (%d)", port, ret);
+	return -EIO;
+}
+
+static int finch_csp_bind_services(void)
+{
+	static const uint8_t service_ports[] = {
+		CSP_CMP,
+		CSP_PING,
+		CSP_MEMFREE,
+		CSP_REBOOT,
+		CSP_BUF_FREE,
+		CSP_UPTIME,
+	};
+
+	for (size_t i = 0; i < ARRAY_SIZE(service_ports); i++) {
+		int ret = finch_csp_bind_service(service_ports[i]);
+
+		if (ret < 0) {
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+int finch_csp_init(void)
+{
+	int ret = 0;
+
+	k_mutex_lock(&finch_csp_lock, K_FOREVER);
+
+	if (finch_csp_initialized) {
+		goto out;
+	}
+
+	csp_conf.hostname = CONFIG_FINCH_CSP_HOSTNAME;
+	csp_conf.model = CONFIG_FINCH_CSP_MODEL;
+	csp_conf.revision = CONFIG_FINCH_CSP_REVISION;
+
+	csp_init();
+
+	csp_if_lo.addr = CONFIG_FINCH_CSP_NODE_ADDRESS;
+
+	ret = finch_csp_bind_services();
+	if (ret < 0) {
+		goto out;
+	}
+
+	finch_csp_router_tid = k_thread_create(
+		&finch_csp_router_thread_data,
+		finch_csp_router_stack,
+		K_THREAD_STACK_SIZEOF(finch_csp_router_stack),
+		finch_csp_router_thread,
+		NULL, NULL, NULL,
+		CONFIG_FINCH_CSP_ROUTER_PRIORITY,
+		0,
+		K_NO_WAIT);
+
+	if (finch_csp_router_tid == NULL) {
+		LOG_ERR("Failed to creat CSP router thread");
+		ret = -EIO;
+		goto out;
+	}
+
+	k_thread_name_set(finch_csp_router_tid, "finch_csp_router");
+	finch_csp_initialized = true;
+
+	LOG_INF("CSP core ready (addr=%u, host=%s)",
+		CONFIG_FINCH_CSP_NODE_ADDRESS,
+		CONFIG_FINCH_CSP_HOSTNAME);
+
+out:
+	k_mutex_unlock(&finch_csp_lock);
+	return ret;
+}