RTWN(4)

NAME
rtwn - Realtek IEEE 802.11 wireless network driver

SYNOPSIS
options RTWN_DEBUG
options RTWN_WITHOUT_UCODE

To compile this driver into the kernel, place the following lines in your kernel configuration file:

device rtwn
device rtwnfw
device rtwn_usb
device rtwn_pci
device wlan
device firmware

Alternatively, to load the driver as a module at boot time, place following lines in loader.conf(5):

    if_rtwn_pci_load="YES"
    if_rtwn_usb_load="YES"

DESCRIPTION
The rtwn driver provides support for wireless network devices based on the Realtek RTL8192C, RTL8188E, RTL8192E, RTL8812A and RTL8821A programming APIs. These APIs are used by a wide variety of chips; most chips with USB and some with PCI interface are supported.

To enable use for PCI/PCIe systems, see the rtwn_pci(4) driver; for USB devices, use the rtwn_usb(4) driver.

The driver supports station, adhoc, hostap and monitor mode operation. There are no limitations for number of monitor mode virtual interfaces; in addition to any other virtual interface one station interface can be added (Note: RTL8821AU supports two non-monitor mode interfaces at the same time).

All chips have hardware support for WEP, AES-CCM and TKIP encryption.

The rtwn driver can be configured at runtime with ifconfig(8).

FILES
/usr/share/doc/legal/realtek.LICENSE
    rtwn firmware license

The driver (if not compiled with options RTWN_WITHOUT_UCODE ) may use following firmware files, which are loaded when an interface is brought up:
/boot/kernel/rtwn-rtl8188eufw.ko
/boot/kernel/rtwn-rtl8192cfwE_B.ko
/boot/kernel/rtwn-rtl8192cfwE.ko
/boot/kernel/rtwn-rtl8192cfwT.ko
/boot/kernel/rtwn-rtl8192cfwU.ko
/boot/kernel/rtwn-rtl8192eufw.ko
/boot/kernel/rtwn-rtl8812aufw.ko
/boot/kernel/rtwn-rtl8821aufw.ko

EXAMPLES
Join an existing BSS network (i.e., connect to an access point):

    ifconfig wlan create wlandev rtwn0 inet 192.168.0.20 \
        netmask 0xffffff00

Join a specific BSS network with network name “my_net”:

    ifconfig wlan create wlandev rtwn0 ssid my_net up

Join a specific BSS network with 64-bit WEP encryption:

    ifconfig wlan create wlandev rtwn0 ssid my_net \
            wepmode on wepkey 0x1234567890 weptxkey 1 up

Create an IBSS network with 128-bit WEP encryption on the channel 4:

    ifconfig wlan create wlandev rtwn0 wlanmode adhoc ssid my_net \
    	wepmode on wepkey 0x01020304050607080910111213 weptxkey 1 \
    	channel 4

Join/create an 802.11b IBSS network with network name “my_net”:

    ifconfig wlan0 create wlandev rtwn0 wlanmode adhoc
    ifconfig wlan0 inet 192.168.0.22 netmask 0xffffff00 ssid my_net \
    	mode 11b

Create a host-based access point:

    ifconfig wlan0 create wlandev rtwn0 wlanmode hostap
    ifconfig wlan0 inet 192.168.0.10 netmask 0xffffff00 ssid my_ap

LOADER TUNABLES
Tunables can be set at the loader(8) prompt before booting the kernel or stored in loader.conf(5).

dev.rtwn.%d.hwcrypto
    This tunable controls how key slots are assigned:
    0 - disable h/w crypto support. Features that require access to frame contents (e.g., TCP/UDP/IP Rx checksum validation) will not work;
    1 - use h/w crypto support for pairwise keys only;
    2 - use h/w crypto support for all keys; may not work for multi-vap configurations.
    By default it is set to 1.

dev.rtwn.%d.ratectl
    This tunable switches between rate control implementations:
    0 - no rate control;
    1 - driver sends 'tx complete' reports to net80211; algorithm is controlled via net80211;
    2 - firmware-based rate control.
    By default it is set to 1; however driver may choose another algorithm in case if it is not implemented
    Currently selected algorithm is reported via dev.rtwn.%d.ratectl_selected read-only OID.

dev.rtwn.%d.rx_buf_size
    (USB only) Controls size of temporary Rx buffer; smaller buffer size may increase number of interrupts.

DIAGNOSTICS

rtwn%d: could not read efuse byte at address 0x%x

rtwn%d: %s: cannot read rom, error %d There was an error while reading ROM; device attach will be aborted. This should not happen.

rtwn%d: failed loadfirmware of file %s For some reason, the driver was unable to read the microcode file from the filesystem. The file might be missing or corrupted. The driver will disable firmware-dependent features.

rtwn%d: wrong firmware size (%zu)

rtwn%d: %s: failed to upload firmware %s (error %d)

rtwn%d: timeout waiting for firmware readiness Firmware upload failed; the file might be corrupted. The driver will disable firmware-dependent features. This should not happen.

rtwn%d: device timeout A frame dispatched to the hardware for transmission did not complete in time. The driver will reset the hardware. This should not happen.

SEE ALSO
intro(4), netintro(4), rtwn_pci(4), rtwn_usb(4), rtwnfw(4), wlan(4), wlan_amrr(4), wlan_ccmp(4), wlan_tkip(4), wlan_wep(4), wlan_xauth(4), hostapd(8), ifconfig(8), wpa_supplicant(8)

HISTORY
The urtwn driver first appeared in OpenBSD 4.9 and FreeBSD 10.0; the rtwn driver first appeared in OpenBSD 5.8.

AUTHORS
The rtwn driver was initially written by -nosplit Stefan Sperling <stsp@openbsd.org> and ported by Kevin Lo <kevlo@freebsd.org>. It was based on the urtwn driver written by Damien Bergamini <damien.bergamini@free.fr>.

BUGS
The rtwn driver currently does not implement firmware-based rate control.