Buildroot and raspberry pi 3 bluetooth HCI not exist

Question

I tried building an image with buildroot that will have bluetooth. The image is configure with busybox init and not with systemd. I added bt firmware and i can see the BCM firmware on target. Bluez5 utils and tools I started the following on the target manually modprobe uart_hci /usr/libexec/bluetooth/bluetoothd & I removed the ttyAMA0 from cmdline.txt modprobe rfcomm : bluetooth TTY layer initialized

installed eudev in buildroot

But i don't see any HCI in /dev hcitool dev return empty devices. I cannot call to hciattach yet because hciattach needs an hci device.

Does someone tried to get the bluetooth with buildroot working and can share his findings please? Thank you all!

Answer 1

have you tried using hciattach - https://www.systutorials.com/docs/linux/man/8-hciattach/ to attach the UART HCI adapter to Bluez?

see this question - Bluetooth on Raspberry Pi Zero W, using buildroot

Answer 2

While the answer by Gal Ben-Haim is already correct and pointing in the right direction, a bit of additional info:

The Bluetooth device can be attached by running hciattach /dev/ttyAMA0 bcm43xx 921600 noflow - Afterwards the interface may need to be enabled with hciconfig hci0 up

When using the Pi Zero W or Pi 3, you may or may not use the bt-overlay fix. If your /boot/config.txt has the line dtoverlay=miniuart-bt your Bluetooth device is connected to dev/ttyS0 instead (the hciattach command needs to be changed accordingly).

To check if everything works as expected, run hcitool lescan