Usually a firmware upgrade of the STM32FXXX boards are is not an easy task for customers. They have to plug the board and use several different tools to flash the memory. For that reason i have made a simple, effective and easy way to upgrade your firmware using an SD Card.
The upgrade task is simple, just write your firmware in the first sector of the SD Card (use HxD application to perform this operation), reboot your system, and the bootloader will upgrade the firmware.
Below is a video demonstration of the firmware upgrade process:
You can have the binary of stitch bootloade here: Stitch Bootloader for STM32F769 as it is, but if you want a personalized version or premium support please contact me.
(This binary should be flashed at 0x08000000)