STM32 USB 软件架构比较复杂,建议去看 UM 1734 或者 st wiki
STM32 USB call graph

STM32 USB Device Library files organization

Reference
1\]: https://wiki.stmicroelectronics.cn/stm32mcu/wiki/Introduction_to_USB_with_STM32 \[2\]: UM1734
STM32 USB 软件架构比较复杂,建议去看 UM 1734 或者 st wiki
Reference
1\]: https://wiki.stmicroelectronics.cn/stm32mcu/wiki/Introduction_to_USB_with_STM32 \[2\]: UM1734