Comment 32 for bug 1674509

I did the same patch - modify firmware patch and speed initialization patch... and I got bluetooth working on RPi!
I used my own app to test it - https://github.com/Nikolay-Kha/BluetoothAudio
hcitool scan
also works fine. bluetoothctl starts, but I cannot type anything there, don't know why.

Patch, that I did for bluez 5.37 is in the attachment, prebuilt hciattach is also there.
I took and install firmware from here - wget https://archive.raspberrypi.org/debian/pool/main/b/bluez-firmware/^Cuez-firmware_1.2-3+rpi1_all.deb

to start bluetooth I used this commands(script in the attachment also):
sudo ~/bluez/tools/hciattach /dev/ttyAMA0 bcm43xx 921600 noflow -
sudo ~/bluez/tools/hciconfig hci0 up

But, there is always BUT... I experience very weak signal. My bluetooth headset which works normally with 5 meter distance with my phone, doesn't even connect to board with 1 meter. It works only when I put headset right on board. Probably it's just a hardware issue of my RPi board instance... or some system setting, I don't know.