1.4.1.1 Bootloader End Address

This field allows the user to define the maximum size of the bootloader

The maximum size of the bootloader. The actual code begins at address 0x200. The size of the bootloader must be in multiples of the device flash page size which is usually 512 or 1024 in size depending on the device. The start of the application code will be placed at the location immediately following the end of the bootloader. See Bootloader Memory Maps for more information about determining the size of the bootloader.