stm32 XiP with ospi external NOR flash

[FRASTM]

Gives example to execute an application from the external octo NOR flash in XiP mode

1. build and link an application for the external NOR with sysbuild
2. define the external NOR flash base address
3. flash the mcuboot binary file at 0x8000000 and the zephyr.signed bianry file at this external NOR flash base address

Requires patching the ../bootloader/mcuboot/boot/flash_map_extended.c:

diff --git a/boot/zephyr/flash_map_extended.c b/boot/zephyr/flash_map_extended.c
index 64e80085..01cd7465 100644
--- a/boot/zephyr/flash_map_extended.c
+++ b/boot/zephyr/flash_map_extended.c
@@ -18,7 +18,19 @@
 
 BOOT_LOG_MODULE_DECLARE(mcuboot);
 
-#if (!defined(CONFIG_XTENSA) && DT_HAS_CHOSEN(zephyr_flash_controller))
+#if defined(CONFIG_STM32_MEMMAP)
+/* MEMORY MAPPED for XiP on external NOR flash takes the ospi-nor or qspi-nor device */
+#define FLASH_DEVICE_ID SPI_FLASH_0_ID
+#if DT_NODE_HAS_STATUS(DT_INST(0, st_stm32_ospi_nor), okay)
+#define FLASH_DEVICE_NODE DT_INST(0, st_stm32_ospi_nor)
+#elif DT_NODE_HAS_STATUS(DT_INST(0, st_stm32_qspi_nor), okay)
+#define FLASH_DEVICE_NODE DT_INST(0, st_stm32_qspi_nor)
+#else
+#error "FLASH_DEVICE_NODE could not be determined"
+#endif
+#define FLASH_DEVICE_BASE CONFIG_STM32_MEMMAP_EXT_FLASH_BASE_ADDRESS
+
+#elif (!defined(CONFIG_XTENSA) && DT_HAS_CHOSEN(zephyr_flash_controller))
 #define FLASH_DEVICE_ID SOC_FLASH_0_ID
 #define FLASH_DEVICE_BASE CONFIG_FLASH_BASE_ADDRESS
 #define FLASH_DEVICE_NODE DT_CHOSEN(zephyr_flash_controller)

Requires a ../bootloader/mcuboot/boot/zephyr/boards/ .conf and .overlay files to set
CONFIG_BOOT_DIRECT_XIP=y
CONFIG_STM32_MEMMAP=y
CONFIG_STM32_MEMMAP_EXT_FLASH_BASE_ADDRESS
and define the slot1 partition of the external NOR flash and as the <zephyr,chosen>

[FRASTM]

Example to build and link an application for the external NOR and execute it in XiP.
$ west build -p always -b stm32h735g_disco samples/boards/stm32/hello_world_xip/ --sysbuild -- -DCONFIG_FLASH_BASE_ADDRESS=0x90000000

Flashing operation is done with the STM32CubeProgrammer application or command line:

1. $ ~/STM32CubeProgrammer/bin/STM32_Programmer_CLI -c port=swd -w32 0x08000000 0x000 -d build/mcuboot/zephyr/zephyr.hex
2. $ ~/STM32CubeProgrammer/bin/STM32_Programmer_CLI -c port=swd -w32 0x90000000 0x000 -el ~/STM32CubeProgrammer/bin/ExternalLoader/MX25LM51245G_STM32H735G-DK.stldr -d build/with_mcuboot/zephyr/zephyr.signed.hex -rst

*** Booting Zephyr OS build zephyr-v3.5.0-656-g3d152069b087 ***
I: Starting Direct-XIP bootloader
I: Image 0 Primary slot: Image not found
I: Secondary slot: version=0.0.0+0
I: Image 0 loaded from the secondary slot
I: Bootloader chainload address offset: 0x0
I: Jumping to the image slot
*** Booting Zephyr OS build zephyr-v3.5.0-656-g3d152069b087 ***
Hello World! from external flash  stm32h735g_disco

[FRASTM]

It is also consist in :
west build -p always -b stm32h7b3i_dk samples/application_development/sysbuild/with_mcuboot --sysbuild -- -DCONFIG_FLASH_BASE_ADDRESS=0x90000000
and flash 2 different binary files to the 0x8000000 and 0x90000000,

1. There must be a slot1 partition chosen to hold the image to be stored and executed in the external NOR at the defined offset (here is 0)

2. Because of sysbuild/mcuboot.conf
   CONFIG_BOOT_UPGRADE_ONLY=y
   CONFIG_MCUBOOT_DOWNGRADE_PREVENTION=y
   The version of the image to be XiP is not set correctly :

*** Booting Zephyr OS build zephyr-v3.5.0-656-g2437cfca5cd6 ***
W: Failed reading sectors; BOOT_MAX_IMG_SECTORS=128 - too small?
W: Cannot upgrade: slots are not compatible
E: Unable to find bootable image

In case the sysbuild/mcuboot.conf
CONFIG_BOOT_UPGRADE_ONLY=n
CONFIG_MCUBOOT_DOWNGRADE_PREVENTION=n

*** Booting Zephyr OS build zephyr-v3.5.0-656-g16508f68aaf2 ***
*** Booting Zephyr OS build zephyr-v3.5.0-656-g16508f68aaf2 ***
Address of sample 0x90000000
Hello sysbuild with mcuboot! stm32h7b3i_dk

[FRASTM]

not relevant anymore

Refer to #68597