Has anyone use STM32 development boards and build the controller

if so any good instructions how to install the IMU and Flash the board with Bootloader and Arducopter Firmware

STM32F427 flash Cortex M4
STM32F407VGT6 ARM Cortex-M4

cant seem to find clear direct instructions for these boards

There are no clear direct instructions for those boards.

But there are generic clear and direct porting to new board instructions