boards: st: stm32h7s3l8 nucleo board for XiP on external flash

Add the memory attributes to XiP in MemoryMapped mode on the
external octo-flash of the nucleo_h7s3l8 board.
Use the STM32Cube programmer to flash with the corresponding
external loader for XiP mode.

Signed-off-by: Francois Ramu <francois.ramu@st.com>

boards/st/nucleo_h7s3l8/board.cmake

@@ -2,6 +2,9 @@
 
 # keep first
 board_runner_args(stm32cubeprogrammer "--port=swd" "--reset-mode=hw")
+if(CONFIG_XIP AND (CONFIG_STM32_MEMMAP OR CONFIG_BOOTLOADER_MCUBOOT))
+  board_runner_args(stm32cubeprogrammer "--extload=MX25UW25645G_NUCLEO-H7S3L8.stldr")
+endif()
 
 board_runner_args(openocd --target-handle=_CHIPNAME.cpu0)
 

boards/st/nucleo_h7s3l8/nucleo_h7s3l8.dts

@@ -57,6 +57,15 @@
 		led2 = &red_led;
 		sw0 = &user_button;
 		watchdog0 = &iwdg;
+		spi-flash0 = &mx25uw25645;
+	};
+
+	ext_memory: memory@70000000 {
+		compatible = "zephyr,memory-region";
+		reg = <0x70000000 DT_SIZE_M(64)>;
+		zephyr,memory-region = "EXTMEM";
+		/* The ATTR_MPU_EXTMEM attribut causing a MPU FAULT */
+		zephyr,memory-attr = <( DT_MEM_ARM(ATTR_MPU_IO) )>;
 	};
 };
 
@@ -189,6 +198,7 @@
 		ospi-max-frequency = <DT_FREQ_M(50)>;
 		spi-bus-width = <XSPI_OCTO_MODE>;
 		data-rate = <XSPI_DTR_TRANSFER>;
+		four-byte-opcodes;
 		status = "okay";
 
 		partitions {