boards: arm: stm32h7b3 disco with external memory region for XiP

Declare a sub-region of the whole ext_memory with attributes
ATTR_MPU_IO so that XiP becomes possible on this external
octo- NOR flash.  Use the STM32CubeProgrammer runner
with the external loader for flashing.

Signed-off-by: Francois Ramu <[email protected]>

Author: FRASTM

boards/st/stm32h7b3i_dk/board.cmake

@@ -4,5 +4,14 @@
 board_runner_args(jlink "--device=STM32H7B3LI" "--speed=4000")
 board_runner_args(openocd --target-handle=_CHIPNAME.cpu0)
 
+if(CONFIG_STM32_MEMMAP)
+board_runner_args(stm32cubeprogrammer "--port=swd" "--reset-mode=hw")
+board_runner_args(stm32cubeprogrammer "--hex-file=${ZEPHYR_BASE}/build/zephyr/zephyr.hex")
+board_runner_args(stm32cubeprogrammer "--extload=MX25LM51245G_STM32H7B3I-DISCO.stldr")
+else()
+board_runner_args(stm32cubeprogrammer "--erase" "--port=swd" "--reset-mode=hw" )
+endif()
+
+include(${ZEPHYR_BASE}/boards/common/stm32cubeprogrammer.board.cmake)
 include(${ZEPHYR_BASE}/boards/common/openocd.board.cmake)
 include(${ZEPHYR_BASE}/boards/common/jlink.board.cmake)

boards/st/stm32h7b3i_dk/stm32h7b3i_dk.dts

@@ -59,6 +59,14 @@
 		zephyr,memory-attr = <( DT_MEM_ARM(ATTR_MPU_RAM_NOCACHE) )>;
 	};
 
+	octo_nor: memory@90000000 {
+		compatible = "zephyr,memory-region";
+		reg = <0x90000000 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) )>;
+	};
+
 	transceiver0: can-phy0 {
 		compatible = "microchip,mcp2562fd", "can-transceiver-gpio";
 		standby-gpios = <&gpioh 8 GPIO_ACTIVE_HIGH>;