We’re developing a couple of boards based on the STM32F072RB. We would like to use mbed-os for this work.
However, we chose to use a different dev board than the (mbed-supported) Nucleo F072RB because the Nucleo doesn’t provide a USB device connector.
STMicro has an eval board called the STM32072B-EVAL that uses the STM32F072VB MCU and provides a USB device connector. We’re using this board for development instead of the NUCLEO_F072RB because we need the USB device capability. This board has a STLINK-V2 debug port that is usable with pyocd (if you add --target STM32F051)
The STM32F072VB MCU is the 100-pin package version of the 64-pin STM32F072RB that is used in the existing NUCLEO_F072RB target. Other than the available pins, these processors are identical.
The NUCLEO_F072RB board doesn’t provide a USB device connector, although it has a USB PHY and controller. I assume that this is why the Nucleo board doesn’t define USB_DEVICE.
I would like to add a TARGET_STM32F072xB directory above TARGET_NUCLEO_F072RB and a TARGET_STM32F072VB directory parallel to the TARGET_NUCLEO_F072RB directory.
The resultant structure would look like this:
mbed-os/targets/TARGET_STM
├── TARGET_STM32F0
│ ├── device
│ │ ├── stm32f0xx_hal_*
│ │ ├── stm32f0xx_ll_*
│ │ ├── stm32_hal_legacy.h
│ │ └── system_stm32f0xx.c
│ ├── TARGET_STM32F072xB
│ │ ├── device
│ │ │ ├── TOOLCHAIN_ARM_MICRO
│ │ │ │ ├── startup_stm32f072xb.S
│ │ │ │ └── stm32f072rb.sct
│ │ │ ├── TOOLCHAIN_ARM_STD
│ │ │ │ ├── startup_stm32f072xb.S
│ │ │ │ └── stm32f072rb.sct
│ │ │ ├── TOOLCHAIN_GCC_ARM
│ │ │ │ ├── startup_stm32f072xb.S
│ │ │ │ └── STM32F072XB.ld
│ │ │ ├── TOOLCHAIN_IAR
│ │ │ │ ├── startup_stm32f072xb.S
│ │ │ │ └── stm32f072xb.icf
│ │ │ ├── cmsis_nvic.c
│ │ │ ├── cmsis_nvic.h
│ │ │ ├── stm32f072xb.h
│ │ │ ├── stm32f0xx.h
│ │ │ ├── system_clock.c
│ │ │ ├── system_stm32f0xx.h
│ │ │ └── us_ticker_data.h
│ │ ├── TARGET_NUCLEO_F072RB
│ │ │ ├── PeripheralNames.h
│ │ │ ├── PeripheralPins.c
│ │ │ └── PinNames.h
│ │ ├── TARGET_STM32F072VB
│ │ │ ├── PeripheralNames.h
│ │ │ ├── PeripheralPins.c
│ │ │ └── PinNames.h
│ │ └── objects.h
│ └── <files>
├── <files>
├── USBEndpoints_STM32.h
├── USBPhyHw.h
└── USBPhy_STM32.cpp
Alternatively, the TARGET_STM32F072VB directory could be called TARGET_STM32072B_EVAL and its pin definitions could reflect the usage on the STM32072B-EVAL board.
I would be willing to do this work and submit a PR, but don’t know whether this is something that the mbed team would be willing to merge.
I also don’t know what impact this would have on tests; there are existing USB device tests but I don’t know whether additional work would be needed for this new target.