boards: st: nucleo_u385rg_q: add flash partition

Define fixed partitions for bootloader (mcuboot),
primary and secondary images, and storage.

Signed-off-by: Khaoula Bidani <khaoula.bidani-ext@st.com>

Author: kbidani

boards/st/nucleo_u385rg_q/nucleo_u385rg_q.dts

@@ -19,6 +19,7 @@
 		zephyr,shell-uart = &usart1;
 		zephyr,sram = &sram0;
 		zephyr,flash = &flash0;
+		zephyr,code-partition = &slot0_partition;
 	};
 
 	leds: leds {
@@ -47,6 +48,39 @@
 	};
 };
 
+&flash0 {
+	partitions {
+		compatible = "fixed-partitions";
+		#address-cells = <1>;
+		#size-cells = <1>;
+
+		/*
+		 * The following partitioning is dedicated to the use of nucleo_u385rg_q
+		 * with TZEN=0 (i.e., without TF-M).
+		 * Place partitions within first 512 KiB to make use of the whole Bank1.
+		 */
+		boot_partition: partition@0 {
+			label = "mcuboot";
+			reg = <0x00000000 DT_SIZE_K(64)>;
+		};
+
+		slot0_partition: partition@10000 {
+			label = "image-0";
+			reg = <0x00010000 DT_SIZE_K(192)>;
+		};
+
+		slot1_partition: partition@40000 {
+			label = "image-1";
+			reg = <0x00040000 DT_SIZE_K(192)>;
+		};
+
+		storage_partition: partition@70000 {
+			label = "storage";
+			reg = <0x00070000 DT_SIZE_K(64)>;
+		};
+	};
+};
+
 &usart1 {
 	pinctrl-0 = <&usart1_tx_pa9 &usart1_rx_pa10>;
 	pinctrl-names = "default";