[MTCD  Android Head Units Q&A] notime2d8:
Well...I'm failing so far. I'm really thinking this may be a no go unless we get a kernel booting from the source code that we do have or one of the radio manufacturers release the source code.

I added the driver and built a module with the Rockchip 4.4 kernel source that's out there, inserted it, and it gave version errors. I tried to manually edit the version info and got symbol errors. I'm going to try to match the symbols or kernel options more and see if it loads. This would all be so easy if we had the actual source code and could build a kernel.

[ 66.188041] usb 3-1.3: New USB device found, idVendor=0bda, idProduct=c820
[ 66.188051] usb 3-1.3: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 66.188060] usb 3-1.3: Product: 802.11ac NIC
[ 66.188068] usb 3-1.3: Manufacturer: Realtek
[ 66.188076] usb 3-1.3: SerialNumber: FF

[ 5.913790] 8821cu: disagrees about version of symbol skb_pull
[ 5.913813] 8821cu: Unknown symbol skb_pull (err -22)
[ 5.913845] 8821cu: disagrees about version of symbol usb_free_coherent
[ 5.913851] 8821cu: Unknown symbol usb_free_coherent (err -22)
[ 5.913895] 8821cu: disagrees about version of symbol netif_napi_del
[ 5.913900] 8821cu: Unknown symbol netif_napi_del (err -22)
[ 5.913922] 8821cu: disagrees about version of symbol __cfg80211_alloc_event_skb
[ 5.913927] 8821cu: Unknown symbol __cfg80211_alloc_event_skb (err -22)
[ 5.913942] 8821cu: disagrees about version of symbol wiphy_register
[ 5.913947] 8821cu: Unknown symbol wiphy_register (err -22)
[ 5.913959] 8821cu: disagrees about version of symbol nla_put
[ 5.913964] 8821cu: Unknown symbol nla_put (err -22)
[ 5.913979] 8821cu: disagrees about version of symbol cfg80211_remain_on_channel_expired
[ 5.913984] 8821cu: Unknown symbol cfg80211_remain_on_channel_expired (err -22)
[ 5.914001] 8821cu: disagrees about version of symbol nla_put_nohdr
[ 5.914006] 8821cu: Unknown symbol nla_put_nohdr (err -22)
[ 5.914034] 8821cu: disagrees about version of symbol wakeup_source_prepare
[ 5.914039] 8821cu: Unknown symbol wakeup_source_prepare (err -22)
[ 5.914050] 8821cu: disagrees about version of symbol __netdev_alloc_skb
[ 5.914055] 8821cu: Unknown symbol __netdev_alloc_skb (err -22)
[ 5.914083] 8821cu: disagrees about version of symbol usb_autopm_put_interface
[ 5.914088] 8821cu: Unknown symbol usb_autopm_put_interface (err -22)
[ 5.914105] 8821cu: disagrees about version of symbol cfg80211_vendor_cmd_reply
[ 5.914111] 8821cu: Unknown symbol cfg80211_vendor_cmd_reply (err -22)
[ 5.914126] 8821cu: disagrees about version of symbol __platform_driver_register
[ 5.914131] 8821cu: Unknown symbol __platform_driver_register (err -22)
[ 5.914147] 8821cu: Unknown symbol __raw_spin_lock_init (err 0)
[ 5.914158] 8821cu: disagrees about version of symbol cfg80211_del_sta_sinfo
[ 5.914164] 8821cu: Unknown symbol cfg80211_del_sta_sinfo (err -22)
[ 5.914175] 8821cu: disagrees about version of symbol netif_tx_stop_all_queues
[ 5.914182] 8821cu: Unknown symbol netif_tx_stop_all_queues (err -22)
[ 5.914196] 8821cu: disagrees about version of symbol seq_release
[ 5.914202] 8821cu: Unknown symbol seq_release (err -22)
[ 5.914211] 8821cu: disagrees about version of symbol wiphy_unregister
[ 5.914216] 8821cu: Unknown symbol wiphy_unregister (err -22)
[ 5.914234] 8821cu: disagrees about version of symbol usb_autopm_get_interface
[ 5.914239] 8821cu: Unknown symbol usb_autopm_get_interface (err -22)
[ 5.914251] 8821cu: disagrees about version of symbol filp_open
[ 5.914256] 8821cu: Unknown symbol filp_open (err -22)
[ 5.914277] 8821cu: disagrees about version of symbol usb_reset_device
[ 5.914282] 8821cu: Unknown symbol usb_reset_device (err -22)
[ 5.914315] 8821cu: disagrees about version of symbol usb_alloc_urb
[ 5.914319] 8821cu: Unknown symbol usb_alloc_urb (err -22)
[ 5.914330] 8821cu: disagrees about version of symbol _raw_spin_lock
[ 5.914335] 8821cu: Unknown symbol _raw_spin_lock (err -22)
[ 5.914345] 8821cu: disagrees about version of symbol __pskb_pull_tail
[ 5.914350] 8821cu: Unknown symbol __pskb_pull_tail (err -22)
[ 5.914369] 8821cu: disagrees about version of symbol single_open
[ 5.914374] 8821cu: Unknown symbol single_open (err -22)
[ 5.914402] 8821cu: disagrees about version of symbol param_ops_int
[ 5.914408] 8821cu: Unknown symbol param_ops_int (err -22)
[ 5.914418] 8821cu: disagrees about version of symbol usb_control_msg
[ 5.914424] 8821cu: Unknown symbol usb_control_msg (err -22)
[ 5.914436] 8821cu: disagrees about version of symbol netif_wake_subqueue
[ 5.914443] 8821cu: Unknown symbol netif_wake_subqueue (err -22)
[ 5.914456] 8821cu: disagrees about version of symbol wakeup_source_add
[ 5.914461] 8821cu: Unknown symbol wakeup_source_add (err -22)
[ 5.914478] 8821cu: disagrees about version of symbol _raw_spin_unlock_irqrestore
[ 5.914484] 8821cu: Unknown symbol _raw_spin_unlock_irqrestore (err -22)
[ 5.914492] 8821cu: disagrees about version of symbol filp_close
[ 5.914497] 8821cu: Unknown symbol filp_close (err -22)
[ 5.914511] 8821cu: disagrees about version of symbol usb_put_dev
[ 5.914517] 8821cu: Unknown symbol usb_put_dev (err -22)
[ 5.914533] 8821cu: disagrees about version of symbol skb_clone
[ 5.914538] 8821cu: Unknown symbol skb_clone (err -22)
[ 5.914572] 8821cu: Unknown symbol _mcount (err 0)
[ 5.914583] 8821cu: disagrees about version of symbol cfg80211_ready_on_channel
[ 5.914588] 8821cu: Unknown symbol cfg80211_ready_on_channel (err -22)
[ 5.914612] 8821cu: disagrees about version of symbol __ieee80211_get_channel
[ 5.914618] 8821cu: Unknown symbol __ieee80211_get_channel (err -22)
[ 5.914629] 8821cu: disagrees about version of symbol skb_put
[ 5.914634] 8821cu: Unknown symbol skb_put (err -22)
[ 5.914651] 8821cu: disagrees about version of symbol proc_get_parent_data
[ 5.914657] 8821cu: Unknown symbol proc_get_parent_data (err -22)
[ 5.914669] 8821cu: disagrees about version of symbol down_interruptible
[ 5.914674] 8821cu: Unknown symbol down_interruptible (err -22)
[ 5.914691] 8821cu: disagrees about version of symbol seq_open
[ 5.914696] 8821cu: Unknown symbol seq_open (err -22)
[ 5.914707] 8821cu: disagrees about version of symbol _raw_spin_unlock_bh
[ 5.914712] 8821cu: Unknown symbol _raw_spin_unlock_bh (err -22)
[ 5.914726] 8821cu: Unknown symbol preempt_count_sub (err 0)
[ 5.914741] 8821cu: disagrees about version of symbol device_init_wakeup
[ 5.914746] 8821cu: Unknown symbol device_init_wakeup (err -22)
[ 5.914762] 8821cu: disagrees about version of symbol wiphy_free
[ 5.914767] 8821cu: Unknown symbol wiphy_free (err -22)
[ 5.914777] 8821cu: disagrees about version of symbol param_array_ops
[ 5.914782] 8821cu: Unknown symbol param_array_ops (err -22)
[ 5.914790] 8821cu: disagrees about version of symbol wiphy_new_nm
[ 5.914795] 8821cu: Unknown symbol wiphy_new_nm (err -22)
[ 5.914805] 8821cu: disagrees about version of symbol cfg80211_get_bss
[ 5.914810] 8821cu: Unknown symbol cfg80211_get_bss (err -22)
[ 5.914821] 8821cu: disagrees about version of symbol complete
[ 5.914826] 8821cu: Unknown symbol complete (err -22)
[ 5.914835] 8821cu: disagrees about version of symbol seq_printf
[ 5.914840] 8821cu: Unknown symbol seq_printf (err -22)
[ 5.914869] 8821cu: disagrees about version of symbol __cfg80211_send_event_skb
[ 5.914874] 8821cu: Unknown symbol __cfg80211_send_event_skb (err -22)
[ 5.914884] 8821cu: disagrees about version of symbol init_net
[ 5.914889] 8821cu: Unknown symbol init_net (err -22)
[ 5.914915] 8821cu: disagrees about version of symbol netif_device_attach
[ 5.914921] 8821cu: Unknown symbol netif_device_attach (err -22)
[ 5.914930] 8821cu: disagrees about version of symbol kthread_stop
[ 5.914935] 8821cu: Unknown symbol kthread_stop (err -22)
[ 5.914949] 8821cu: disagrees about version of symbol cfg80211_disconnected
[ 5.914954] 8821cu: Unknown symbol cfg80211_disconnected (err -22)
[ 5.914962] 8821cu: disagrees about version of symbol complete_and_exit
[ 5.914968] 8821cu: Unknown symbol complete_and_exit (err -22)
[ 5.914976] 8821cu: disagrees about version of symbol netif_tx_wake_queue
[ 5.914982] 8821cu: Unknown symbol netif_tx_wake_queue (err -22)
[ 5.914992] 8821cu: disagrees about version of symbol cfg80211_michael_mic_failure
[ 5.914997] 8821cu: Unknown symbol cfg80211_michael_mic_failure (err -22)
[ 5.915006] 8821cu: disagrees about version of symbol skb_dequeue
[ 5.915011] 8821cu: Unknown symbol skb_dequeue (err -22)
[ 5.915021] 8821cu: disagrees about version of symbol usb_deregister
[ 5.915026] 8821cu: Unknown symbol usb_deregister (err -22)
[ 5.915041] 8821cu: disagrees about version of symbol netif_rx
[ 5.915046] 8821cu: Unknown symbol netif_rx (err -22)
[ 5.915054] 8821cu: disagrees about version of symbol cfg80211_ibss_joined
[ 5.915059] 8821cu: Unknown symbol cfg80211_ibss_joined (err -22)
[ 5.915072] 8821cu: disagrees about version of symbol skb_copy_bits
[ 5.915077] 8821cu: Unknown symbol skb_copy_bits (err -22)
[ 5.915090] 8821cu: disagrees about version of symbol param_ops_charp
[ 5.915095] 8821cu: Unknown symbol param_ops_charp (err -22)
[ 5.915103] 8821cu: disagrees about version of symbol skb_copy
[ 5.915108] 8821cu: Unknown symbol skb_copy (err -22)
[ 5.915116] 8821cu: disagrees about version of symbol PDE_DATA
[ 5.915121] 8821cu: Unknown symbol PDE_DATA (err -22)
[ 5.915129] 8821cu: disagrees about version of symbol seq_lseek
[ 5.915134] 8821cu: Unknown symbol seq_lseek (err -22)
[ 5.915145] 8821cu: disagrees about version of symbol register_netdevice
[ 5.915150] 8821cu: Unknown symbol register_netdevice (err -22)
[ 5.915159] 8821cu: disagrees about version of symbol wake_up_process
[ 5.915164] 8821cu: Unknown symbol wake_up_process (err -22)
[ 5.915174] 8821cu: disagrees about version of symbol __vfs_read
[ 5.915179] 8821cu: Unknown symbol __vfs_read (err -22)
[ 5.915189] 8821cu: disagrees about version of symbol kthread_create_on_node
[ 5.915194] 8821cu: Unknown symbol kthread_create_on_node (err -22)
[ 5.915203] 8821cu: disagrees about version of symbol wakeup_source_drop
[ 5.915208] 8821cu: Unknown symbol wakeup_source_drop (err -22)
[ 5.915216] 8821cu: disagrees about version of symbol param_ops_uint
[ 5.915221] 8821cu: Unknown symbol param_ops_uint (err -22)
[ 5.915231] 8821cu: disagrees about version of symbol usb_get_dev
[ 5.915236] 8821cu: Unknown symbol usb_get_dev (err -22)
[ 5.915255] 8821cu: disagrees about version of symbol platform_get_resource_byname
[ 5.915260] 8821cu: Unknown symbol platform_get_resource_byname (err -22)
[ 5.915268] 8821cu: disagrees about version of symbol netif_carrier_off
[ 5.915273] 8821cu: Unknown symbol netif_carrier_off (err -22)
[ 5.915282] 8821cu: disagrees about version of symbol __pm_relax
[ 5.915287] 8821cu: Unknown symbol __pm_relax (err -22)
[ 5.915296] 8821cu: disagrees about version of symbol mutex_lock_interruptible
[ 5.915301] 8821cu: Unknown symbol mutex_lock_interruptible (err -22)
[ 5.915309] 8821cu: disagrees about version of symbol seq_read
[ 5.915314] 8821cu: Unknown symbol seq_read (err -22)
[ 5.915325] 8821cu: disagrees about version of symbol napi_complete_done
[ 5.915330] 8821cu: Unknown symbol napi_complete_done (err -22)
[ 5.915338] 8821cu: disagrees about version of symbol down_timeout
[ 5.915342] 8821cu: Unknown symbol down_timeout (err -22)
[ 5.915356] 8821cu: disagrees about version of symbol __mutex_init
[ 5.915361] 8821cu: Unknown symbol __mutex_init (err -22)
[ 5.915377] 8821cu: disagrees about version of symbol cfg80211_scan_done
[ 5.915382] 8821cu: Unknown symbol cfg80211_scan_done (err -22)
[ 5.915391] 8821cu: disagrees about version of symbol jiffies
[ 5.915396] 8821cu: Unknown symbol jiffies (err -22)
[ 5.915406] 8821cu: disagrees about version of symbol remove_proc_entry
[ 5.915411] 8821cu: Unknown symbol remove_proc_entry (err -22)
[ 5.915419] 8821cu: disagrees about version of symbol cfg80211_roamed
[ 5.915424] 8821cu: Unknown symbol cfg80211_roamed (err -22)
[ 5.915432] 8821cu: disagrees about version of symbol cfg80211_put_bss
[ 5.915437] 8821cu: Unknown symbol cfg80211_put_bss (err -22)
[ 5.915446] 8821cu: disagrees about version of symbol register_netdev
[ 5.915451] 8821cu: Unknown symbol register_netdev (err -22)
[ 5.915465] 8821cu: disagrees about version of symbol __pm_wakeup_event
[ 5.915470] 8821cu: Unknown symbol __pm_wakeup_event (err -22)
[ 5.915478] 8821cu: disagrees about version of symbol up
[ 5.915482] 8821cu: Unknown symbol up (err -22)
[ 5.915490] 8821cu: disagrees about version of symbol netif_napi_add
[ 5.915495] 8821cu: Unknown symbol netif_napi_add (err -22)
[ 5.915502] 8821cu: disagrees about version of symbol _raw_spin_lock_bh
[ 5.915508] 8821cu: Unknown symbol _raw_spin_lock_bh (err -22)
[ 5.915522] 8821cu: disagrees about version of symbol skb_trim
[ 5.915526] 8821cu: Unknown symbol skb_trim (err -22)
[ 5.915535] 8821cu: disagrees about version of symbol kill_pid
[ 5.915540] 8821cu: Unknown symbol kill_pid (err -22)
[ 5.915557] 8821cu: disagrees about version of symbol wait_for_completion_timeout
[ 5.915562] 8821cu: Unknown symbol wait_for_completion_timeout (err -22)
[ 5.915570] 8821cu: disagrees about version of symbol skb_push
[ 5.915575] 8821cu: Unknown symbol skb_push (err -22)
[ 5.915586] 8821cu: disagrees about version of symbol usb_alloc_coherent
[ 5.915592] 8821cu: Unknown symbol usb_alloc_coherent (err -22)
[ 5.915604] 8821cu: disagrees about version of symbol find_vpid
[ 5.915608] 8821cu: Unknown symbol find_vpid (err -22)
[ 5.915617] 8821cu: disagrees about version of symbol proc_create_data
[ 5.915622] 8821cu: Unknown symbol proc_create_data (err -22)
[ 5.915631] 8821cu: disagrees about version of symbol __dev_kfree_skb_any
[ 5.915635] 8821cu: Unknown symbol __dev_kfree_skb_any (err -22)
[ 5.915646] 8821cu: disagrees about version of symbol cfg80211_unlink_bss
[ 5.915651] 8821cu: Unknown symbol cfg80211_unlink_bss (err -22)
[ 5.915660] 8821cu: disagrees about version of symbol netif_carrier_on
[ 5.915665] 8821cu: Unknown symbol netif_carrier_on (err -22)
[ 5.915672] 8821cu: disagrees about version of symbol _raw_spin_lock_irqsave
[ 5.915677] 8821cu: Unknown symbol _raw_spin_lock_irqsave (err -22)
[ 5.915686] 8821cu: disagrees about version of symbol usb_kill_urb
[ 5.915691] 8821cu: Unknown symbol usb_kill_urb (err -22)
[ 5.915700] 8821cu: disagrees about version of symbol dev_alloc_name
[ 5.915705] 8821cu: Unknown symbol dev_alloc_name (err -22)
[ 5.915717] 8821cu: disagrees about version of symbol wait_for_completion
[ 5.915722] 8821cu: Unknown symbol wait_for_completion (err -22)
[ 5.915731] 8821cu: disagrees about version of symbol cfg80211_connect_result
[ 5.915736] 8821cu: Unknown symbol cfg80211_connect_result (err -22)
[ 5.915749] 8821cu: disagrees about version of symbol cfg80211_inform_bss_frame_data
[ 5.915754] 8821cu: Unknown symbol cfg80211_inform_bss_frame_data (err -22)
[ 5.915767] 8821cu: disagrees about version of symbol flush_signals
[ 5.915772] 8821cu: Unknown symbol flush_signals (err -22)
[ 5.915781] 8821cu: disagrees about version of symbol unregister_netdev
[ 5.915786] 8821cu: Unknown symbol unregister_netdev (err -22)
[ 5.915799] 8821cu: disagrees about version of symbol usb_free_urb
[ 5.915803] 8821cu: Unknown symbol usb_free_urb (err -22)
[ 5.915810] 8821cu: disagrees about version of symbol cfg80211_new_sta
[ 5.915815] 8821cu: Unknown symbol cfg80211_new_sta (err -22)
[ 5.915824] 8821cu: disagrees about version of symbol alloc_etherdev_mqs
[ 5.915829] 8821cu: Unknown symbol alloc_etherdev_mqs (err -22)
[ 5.915838] 8821cu: disagrees about version of symbol mutex_unlock
[ 5.915843] 8821cu: Unknown symbol mutex_unlock (err -22)
[ 5.915860] 8821cu: disagrees about version of symbol netif_receive_skb
[ 5.915865] 8821cu: Unknown symbol netif_receive_skb (err -22)
[ 5.915872] 8821cu: disagrees about version of symbol _raw_spin_unlock
[ 5.915877] 8821cu: Unknown symbol _raw_spin_unlock (err -22)
[ 5.915887] 8821cu: disagrees about version of symbol usb_submit_urb
[ 5.915892] 8821cu: Unknown symbol usb_submit_urb (err -22)
[ 5.915900] 8821cu: disagrees about version of symbol __init_waitqueue_head
[ 5.915905] 8821cu: Unknown symbol __init_waitqueue_head (err -22)
[ 5.915912] 8821cu: disagrees about version of symbol __pskb_copy_fclone
[ 5.915917] 8821cu: Unknown symbol __pskb_copy_fclone (err -22)
[ 5.915928] 8821cu: disagrees about version of symbol unregister_netdevice_queue
[ 5.915933] 8821cu: Unknown symbol unregister_netdevice_queue (err -22)
[ 5.915942] 8821cu: disagrees about version of symbol __cfg80211_alloc_reply_skb
[ 5.915947] 8821cu: Unknown symbol __cfg80211_alloc_reply_skb (err -22)
[ 5.915956] 8821cu: disagrees about version of symbol free_netdev
[ 5.915960] 8821cu: Unknown symbol free_netdev (err -22)
[ 5.915970] 8821cu: disagrees about version of symbol platform_driver_unregister
[ 5.915976] 8821cu: Unknown symbol platform_driver_unregister (err -22)
[ 5.915985] 8821cu: disagrees about version of symbol wakeup_source_remove
[ 5.915990] 8821cu: Unknown symbol wakeup_source_remove (err -22)
[ 5.916002] 8821cu: disagrees about version of symbol napi_disable
[ 5.916006] 8821cu: Unknown symbol napi_disable (err -22)
[ 5.916016] 8821cu: disagrees about version of symbol cfg80211_rx_mgmt
[ 5.916021] 8821cu: Unknown symbol cfg80211_rx_mgmt (err -22)
[ 5.916035] 8821cu: disagrees about version of symbol wiphy_apply_custom_regulatory
[ 5.916040] 8821cu: Unknown symbol wiphy_apply_custom_regulatory (err -22)
[ 5.916048] 8821cu: disagrees about version of symbol dev_get_by_name
[ 5.916053] 8821cu: Unknown symbol dev_get_by_name (err -22)
[ 5.916062] 8821cu: disagrees about version of symbol proc_mkdir_data
[ 5.916067] 8821cu: Unknown symbol proc_mkdir_data (err -22)
[ 5.916076] 8821cu: disagrees about version of symbol __pm_stay_awake
[ 5.916081] 8821cu: Unknown symbol __pm_stay_awake (err -22)
[ 5.916091] 8821cu: disagrees about version of symbol cfg80211_mgmt_tx_status
[ 5.916096] 8821cu: Unknown symbol cfg80211_mgmt_tx_status (err -22)
[ 5.916110] 8821cu: disagrees about version of symbol skb_queue_tail
[ 5.916115] 8821cu: Unknown symbol skb_queue_tail (err -22)
[ 5.916129] 8821cu: disagrees about version of symbol single_release
[ 5.916134] 8821cu: Unknown symbol single_release (err -22)
[ 5.916140] 8821cu: disagrees about version of symbol napi_gro_receive
[ 5.916145] 8821cu: Unknown symbol napi_gro_receive (err -22)
[ 5.916153] 8821cu: disagrees about version of symbol eth_type_trans
[ 5.916158] 8821cu: Unknown symbol eth_type_trans (err -22)
[ 5.916167] 8821cu: disagrees about version of symbol __napi_schedule
[ 5.916172] 8821cu: Unknown symbol __napi_schedule (err -22)
[ 5.916181] 8821cu: disagrees about version of symbol usb_register_driver
[ 5.916186] 8821cu: Unknown symbol usb_register_driver (err -22)
[ 5.916194] 8821cu: Unknown symbol preempt_count_add (err 0)