How to get USB0 Ethernet STM32MP157f-dk2 with buildroot

[Dat Tran]

Hi, the image provided by ST, usb0 ethernet show up as well when try 'ifconfig'.

We would like to try with buildroot.

We pick kernel from ST: linux-5.15-stm32mp-r1.tar.gz

We pick config from ST: en.SOURCES-stm32mp1-openstlinux-5.15-yocto-kirkstone-mp1-v22.06.15.tar.xz (inside the zip has config-5.15.24.txt file)

Building and boot are success. 

We expected to see "usb_gadget" in folder /sys/kernel/config to run "stm32_usbotg_eth_config.sh". But "usb_gadget" folder doesn't appear.

But we tried:

```

mkdir -p /config

mount -t configfs none /config

```

"usb_gadget" does appear inside /config as well.

So, we change path in script "stm32_usbotg_eth_config.sh", instead of "/sys/kernel/config/usb_gadget" become "/config/usb_gadget".

Script run look fine but all we see just:

[  45.084215] using random self ethernet address

[  45.087218] using random host ethernet address

Anyone know what we are missing or any hint?

And why "usb_gadget" only appears when use mount, instead of default "/sys/kernel/config/usb_gadget"?

Many thanks

Note: libcomposite is builtin module but for sure we also tried cmd:

```

modprobe libcomposite

 ```

[OlivierK]

Hi Dat Tran (Community Member) 

Sorry this post is quite old. Did you manage to find a solution to this issue? or maybe in Bootlin community?

https://bootlin.com/blog/building-a-linux-system-for-the-stm32mp1-basic-system/

[Dat Tran]

Hi OlivierK, I got it working very well. Thanks a lot.

By the way, do you know STM32H7 (STM32H743) support usb gadget ethernet?

I see somewhere STM32F7 does, I guess STM32H7 support this feature as well but I am not sure.