Bootloader that Executes In Place (XIP) program stored on QSPI flash memory.
Bootloader on startup runs the comm service that allows you to upload a new
firmware via UART from a host computer.
The bootloader itself is stored in the internal flash memory.
To build a compatible application firmware for bl_qspiflash firmware, link it
with bl_qspiflash_app.ld linker script. This
is a basic linker file that maps the application firmware to the QSPI flash
memory memory region and hides the region where the bootloader is stored.