boot: stm32n6: Define specific executable region

On STM32N6, MCUBoot is loaded by the BootROM to axisram2 and,
when running in RAMLOAD configuration, application image is loaded
in axisram1.
To support this, define MULTIPLE_EXECUTABLE_RAM_REGIONS and implement
boot_get_image_exec_ram_info() which provides the right executable
address and size based on axisram1 node definition.

Signed-off-by: Erwan Gouriou <erwan.gouriou@st.com>

Author: erwango

boot/bootutil/src/ram_load.c

@@ -49,6 +49,18 @@ BOOT_LOG_MODULE_DECLARE(mcuboot);
 #endif
 #endif
 
+#ifdef CONFIG_SOC_SERIES_STM32N6X
+int boot_get_image_exec_ram_info(uint32_t image_id,
+                                 uint32_t *exec_ram_start,
+                                 uint32_t *exec_ram_size)
+{
+    *exec_ram_start = DT_PROP_BY_IDX(DT_NODELABEL(axisram1), reg, 0);
+    *exec_ram_size = DT_PROP_BY_IDX(DT_NODELABEL(axisram1), reg, 1);
+
+    return 0;
+}
+#endif
+
 /**
  * Verifies that the active slot of the current image can be loaded within the
  * predefined bounds that are allowed to be used by executable images.

boot/zephyr/include/mcuboot_config/mcuboot_config.h

@@ -134,6 +134,10 @@
 #define IMAGE_EXECUTABLE_RAM_SIZE CONFIG_BOOT_IMAGE_EXECUTABLE_RAM_SIZE
 #endif
 
+#ifdef CONFIG_SOC_SERIES_STM32N6X
+#define MULTIPLE_EXECUTABLE_RAM_REGIONS
+#endif
+
 #ifdef CONFIG_LOG
 #define MCUBOOT_HAVE_LOGGING 1
 #endif