diff --git a/boot/zephyr/boards/nrf54h20dk_nrf54h20_cpuapp_iron_ext_flash.conf b/boot/zephyr/boards/nrf54h20dk_nrf54h20_cpuapp_iron_ext_flash.conf
new file mode 100644
index 000000000..3124fe1cb
--- /dev/null
+++ b/boot/zephyr/boards/nrf54h20dk_nrf54h20_cpuapp_iron_ext_flash.conf
@@ -0,0 +1,10 @@
+# Copyright (c) 2025 Nordic Semiconductor ASA
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+CONFIG_SPI=y
+CONFIG_FLASH=y
+CONFIG_BOOT_MAX_IMG_SECTORS_AUTO=n
+CONFIG_BOOT_MAX_IMG_SECTORS=512
+CONFIG_FLASH_MSPI_NOR_LAYOUT_PAGE_SIZE=4096
diff --git a/boot/zephyr/boards/nrf54h20dk_nrf54h20_cpuapp_iron_ext_flash.overlay b/boot/zephyr/boards/nrf54h20dk_nrf54h20_cpuapp_iron_ext_flash.overlay
new file mode 100644
index 000000000..eaed4d04a
--- /dev/null
+++ b/boot/zephyr/boards/nrf54h20dk_nrf54h20_cpuapp_iron_ext_flash.overlay
@@ -0,0 +1,35 @@
+/*
+ * Copyright (c) 2025 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
+ */
+
+/delete-node/ &slot1_partition;
+
+/ {
+	chosen {
+		extmem-device = &mx25uw63;
+	};
+};
+
+&mx25uw63 {
+	status = "okay";
+	partitions {
+		compatible = "fixed-partitions";
+		#address-cells = <1>;
+		#size-cells = <1>;
+
+		slot1_partition: partition@0 {
+			label = "image-1";
+			reg = <0x0 DT_SIZE_K(512)>;
+		};
+	};
+};
+
+&mram1x {
+	partitions {
+		slot0_partition: partition@3c000 {
+			reg = <0x3c000 DT_SIZE_K(512)>;
+		};
+	};
+};