[nrf fromlist] boards: nordic: nrf54h20dk iron board MCUBoot support

Provide proper adaptions as bootloader ROM offset, flash load
offset and dts definitions for the nRF54H20 iron board to make it
ready for the MCUBoot bootloader.

Upstream PR #: 88298

Signed-off-by: Michal Kozikowski <[email protected]>
(cherry picked from commit 2c20897)

Author: nordic-mik7

boards/nordic/nrf54h20dk/Kconfig.defconfig

@@ -17,3 +17,13 @@ config MAX_THREAD_BYTES
 	default 3 if USERSPACE
 
 endif # BOARD_NRF54H20DK_NRF54H20_CPURAD
+
+if BOARD_NRF54H20DK_NRF54H20_CPUAPP_IRON
+
+config ROM_START_OFFSET
+	default 0x800 if BOOTLOADER_MCUBOOT
+
+config FLASH_LOAD_OFFSET
+	default 0x2c000 if !USE_DT_CODE_PARTITION
+
+endif # BOARD_NRF54H20DK_NRF54H20_CPUAPP_IRON

boards/nordic/nrf54h20dk/nrf54h20dk_nrf54h20_cpuapp_iron.dts

@@ -14,15 +14,33 @@
  * the application core.
  */
 
+/ {
+	chosen {
+		zephyr,code-partition = &slot0_partition;
+		zephyr,uart-mcumgr = &uart136;
+	};
+};
+
 &mram1x {
 	cpuapp_rx_partitions: cpuapp-rx-partitions {
 		compatible = "nordic,owned-partitions", "fixed-partitions";
 		nordic,access = <NRF_OWNER_ID_APPLICATION NRF_PERM_RXS>;
 		#address-cells = <1>;
 		#size-cells = <1>;
 
-		cpuapp_slot0_partition: partition@2c000 {
-			reg = <0x2c000 DT_SIZE_K(480)>;
+		boot_partition: partition@2c000 {
+			label = "mcuboot";
+			reg = <0x2c000 DT_SIZE_K(64)>;
+		};
+
+		slot0_partition: partition@3c000 {
+			label = "image-0";
+			reg = <0x3c000 DT_SIZE_K(400)>;
+		};
+
+		slot1_partition: partition@6E000 {
+			label = "image-1";
+			reg = <0x6E000 DT_SIZE_K(400)>;
 		};
 
 		cpuppr_code_partition: partition@a4000 {

boards/nordic/nrf54h20dk/nrf54h20dk_nrf54h20_cpuapp_iron_defconfig

@@ -8,8 +8,6 @@ CONFIG_SERIAL=y
 CONFIG_CONSOLE=y
 CONFIG_UART_CONSOLE=y
 
-CONFIG_USE_DT_CODE_PARTITION=y
-
 # Enable MPU
 CONFIG_ARM_MPU=y