Hi,
I work with a Broadcom adapter with AOSP 10, and it's not working on my side as well, using both the graphical interface and the command line interface (terminal).
About the filesystem problem, try using the << chmod >> command on the folder (see documentation on
die.net website).
On my side, I successfully installed the drivers ( or placed them there), but the BT adapter only sees my phone's BT, using the << hcitool scan >> command, and running the command << dmesg | grep Bluetooth >> is prints this:
[ timestamp ] Bluetooth hci0: RTL: rtl: examining hci_ver=0a hci_rev=000c lmp_ver=0a lmp_subver=8822/x0a
[ timestamp ] Bluetooth hci0: RTL: rtl: unknown IC info, lmp subver 8822, hci rev 000c, hci ver 000a
[ timestamp ] Bluetooth hci0: RTL: rtl: assuming no firmware upload needed/x0a
Please, If you found more information about this topic, please reply here, because I am very interested on this topic. Thank you!