STM32F030 is the processor of FC and a STM32 programmer is needed to flash the
firmware through the SWD port (CLK, SWDIO) of the controller. We would recommend
the ST-LINK or BeeLink USB Flasher.
EFM8BB21 is the processor of OSD. You need a efm8 programmer to upload the
firmware through the C2 port (C2CK, C2D) of the controller. We would recommend the
Silicon Lab debug adapter.