Creality 4.3.1 wrong bootloader offset. Board no longer reachable

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Klipper Flash STM32F103 question bootloader,

In basic terms, the bootloader is placed at a location where the code is started at that location during reset or power up; the application offset is a jump point for the code to start after the bootloader code is completed running. Firmware is code that runs in a continuous loop unless a major error has been triggered. The bootloader offset is the point the firmware code starts in flash memory, and it locates the firmware code beyond the bootloader code.