link time flash protection

ports/nordic/boards/common.template.ld

@@ -30,6 +30,22 @@ MEMORY
     APP_RAM (xrw)   : ORIGIN = ${APP_RAM_START_ADDR}, LENGTH = ${APP_RAM_SIZE}
 }
 
+/* Confirm that the flash regions defined above are in order and do not overlap.*/
+ASSERT((ORIGIN(FLASH_ISR) + LENGTH(FLASH_ISR)) <= ORIGIN(FLASH_FIRMWARE),
+    "FLASH_ISR overlaps FLASH_FIRMWARE")
+ASSERT((ORIGIN(FLASH_FIRMWARE) + LENGTH(FLASH_FIRMWARE)) <= ORIGIN(FLASH_BLE_CONFIG),
+    "FLASH_FIRMWARE overlaps FLASH_BLE_CONFIG")
+ASSERT((ORIGIN(FLASH_BLE_CONFIG) + LENGTH(FLASH_BLE_CONFIG)) <= ORIGIN(FLASH_NVM),
+    "FLASH_BLE_CONFIG overlaps FLASH_NVM")
+ASSERT((ORIGIN(FLASH_NVM) + LENGTH(FLASH_NVM)) <= ORIGIN(FLASH_FATFS),
+    "FLASH_NVM overlaps FLASH_FATFS")
+ASSERT((ORIGIN(FLASH_FATFS) + LENGTH(FLASH_FATFS)) <= ORIGIN(FLASH_BOOTLOADER),
+    "FLASH_FATFS overlaps FLASH_BOOTLOADER")
+ASSERT((ORIGIN(FLASH_BOOTLOADER) + LENGTH(FLASH_BOOTLOADER)) <= ORIGIN(FLASH_BOOTLOADER_SETTINGS),
+    "FLASH_BOOTLOADER overlaps FLASH_BOOTLOADER_SETTINGS")
+ASSERT((ORIGIN(FLASH_BOOTLOADER_SETTINGS) + LENGTH(FLASH_BOOTLOADER_SETTINGS)) <= (ORIGIN(FLASH) + LENGTH(FLASH)),
+    "FLASH_BOOTLOADER_SETTINGS extends past the end of FLASH")
+
 /* produce a link error if there is not this amount of RAM available */
 _minimum_heap_size = 0;