Populate /dev in Buildroot

Question

I would like the /dev/i2c* devices to be populated in Buildroot for Pi zero after the i2c_dev module is inserted. Currently just modprobing the module does nothing. According the Buildroot doc I guess I should try to go the devtmpfs + mdev way, is that correct? Any additional hints regarding this topic? (Just waiting for rebuild ;-)

Answer 1

OK. I can confirm that

• using the Buildroot System Configuration | /dev management | Dynamic using devtmpfs + mdev
• together with having dtparam=i2c_arm=on in /boot/config.txt

does the trick. After loading i2c_dev module the /dev/i2c-1 is created.

Answer 2

I was running into a similar problem on my RPi 1, and it was necessary to load the i2c_bcm2835 module.