samples: Bluetooth: iso_central: Add sysbuild to build hci_ipc

Add sysbuild support to build corresponding hci_ipc
firmware for net core on nRF53x boards.

Example build commandline:
  # west build -b nrf5340dk/nrf5340/cpuapp
    -d build/iso_central samples/bluetooth/iso_central

Signed-off-by: Vinayak Kariappa Chettimada <[email protected]>

samples/bluetooth/iso_central/Kconfig.sysbuild

@@ -0,0 +1,15 @@
+# Copyright 2023-2024 Nordic Semiconductor ASA
+# SPDX-License-Identifier: Apache-2.0
+
+source "share/sysbuild/Kconfig"
+
+config NET_CORE_BOARD
+	string
+	default "nrf5340dk/nrf5340/cpunet" if $(BOARD) = "nrf5340dk"
+	default "nrf5340_audio_dk/nrf5340/cpunet" if $(BOARD) = "nrf5340_audio_dk"
+	default "nrf5340bsim/nrf5340/cpunet" if $(BOARD_TARGET_STRING) = "NRF5340BSIM_NRF5340_CPUAPP"
+
+config NET_CORE_IMAGE_HCI_IPC
+	bool "HCI IPC image on network core"
+	default y
+	depends on NET_CORE_BOARD != ""

samples/bluetooth/iso_central/sample.yaml

@@ -4,10 +4,14 @@ sample:
 tests:
   sample.bluetooth.iso_central:
     harness: bluetooth
-    platform_allow: qemu_x86
+    platform_allow:
+      - qemu_x86
+      - nrf5340dk/nrf5340/cpuapp
     integration_platforms:
       - qemu_x86
+      - nrf5340dk/nrf5340/cpuapp
     tags: bluetooth
+    sysbuild: true
   sample.bluetooth.iso_central.bt_ll_sw_split:
     harness: bluetooth
     platform_allow:

samples/bluetooth/iso_central/sysbuild.cmake

@@ -0,0 +1,35 @@
+# Copyright (c) 2023-2024 Nordic Semiconductor ASA
+# SPDX-License-Identifier: Apache-2.0
+
+if(SB_CONFIG_NET_CORE_IMAGE_HCI_IPC)
+	# For builds in the nrf5340, we build the netcore image with the controller
+
+	set(NET_APP hci_ipc)
+	set(NET_APP_SRC_DIR ${ZEPHYR_BASE}/samples/bluetooth/${NET_APP})
+
+	ExternalZephyrProject_Add(
+		APPLICATION ${NET_APP}
+		SOURCE_DIR  ${NET_APP_SRC_DIR}
+		BOARD       ${SB_CONFIG_NET_CORE_BOARD}
+	)
+
+	set(${NET_APP}_CONF_FILE
+	 ${NET_APP_SRC_DIR}/nrf5340_cpunet_iso-bt_ll_sw_split.conf
+	 CACHE INTERNAL ""
+	)
+
+	set(${NET_APP}_SNIPPET
+	 "bt-ll-sw-split"
+	 CACHE INTERNAL ""
+	)
+
+	# Necessary to match the ACL RX size between APP and NET core
+	set(CONFIG_BT_BUF_ACL_RX_SIZE
+	 "255"
+	 CACHE INTERNAL ""
+	)
+
+	native_simulator_set_child_images(${DEFAULT_IMAGE} ${NET_APP})
+endif()
+
+native_simulator_set_final_executable(${DEFAULT_IMAGE})