Gotek Firmware Programming
HxC
You will need to purchase the HxC software and use a USB TLL Programmer (see below) and the SecSerialBridge (download instructions provided after making purchase) to firmware program the Gotek:
https://torlus.com/floppy/forum/viewtopic.php?f=33&t=1683&p=11486#p16455
FlashFloppy
See the following for official instructions on how to program a Gotek with FlashFloppy firmware:
https://github.com/keirf/FlashFloppy/wiki/Firmware-Programming
You will need a USB TTL Programmer and an STM32 firmware programming software - see below.
STM32 Firmware Programming Software
There the following STM32 firmware programming software that can be used:
Flash Loader Demonstrator - https://www.st.com/en/development-tools/flasher-stm32.html
STM32 Cube Programmer - https://www.st.com/en/development-tools/stm32cubeprog.html
USB TTL Programmer
A USB TTL Programmer is required to physically connect to the Gotek to allow firmware programming.
Note that there are several types, based on the chipset. Below are the different chipset types ones I have personally tested with:
CP2102
CH340G
PL2303HX
The USB TTL programmer pins you need to connect are:
5V
GND
TXD
RXD
These should be connected to the Gotek pins appropriately:
5V to 5V on floppy power connector.
GND to one of the GND on the floppy power connector.
TXD to RX (J4) on the programming header.
RXD to TX on the programming header.
If you cannot connect to the Gotek using the USB TTL programmer (using the STM32 firmware programming software) try the following:
Check the pinouts on the USB TTL programmer - they do not all have the same pinouts!
Check that TXD and RXD are connected correctly - they need to be crossed going to the Gotek. Swap them if you are unsure.
Make sure BOOT0 (J3) is jumpered to 3.3V.
Send a reset signal to the device - connect the RST pin briefly to a GND (ground) point.
CP2102
Flash Loader Demonstrator = !!! DOES NOT WORK !!!
For some reason I could not get this to work with Flash Loader Demonstrator.
STM32 Cube Programmer = WORKS
The exact same setup works with STM32 Cube Programmer.
CH340G
Flash Loader Demonstrator = WORKS
STM32 Cube Programmer = WORKS
PL2303HX
Note: On Windows 8 and 10, you need to install the older Prolific drivers. See http://wp.brodzinski.net/hardware/fake-pl2303-how-to-install/
Flash Loader Demonstrator = WORKS
STM32 Cube Programmer = WORKS