OTUS(4)

💅 OTUS(4) — the Kernel Interfaces Manual, but make it cute

okay so this is the otus(4) page from the Debian edition of the Kernel Interfaces Manual, and we're gonna get you so comfy with this driver, bestie. it's the Atheros AR9170 USB IEEE 802.11a/b/g/n wireless network driver, and yes the "n" in that list is a little bit of a lie — more on that in CAVEATS, stay tuned 🎀

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✨ NAME ✨

otus — the Atheros AR9170 USB IEEE 802.11a/b/g/n wireless network driver. that's the whole name section, she's short and she knows it 💅

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🌸 SYNOPSIS 🌸

so if you wanna compile this driver into the kernel (main character energy, no modules), you drop these lines into your kernel configuration file:

device ehci
device uhci
device ohci
device usb
device otus
device wlan

alternatively — and honestly this is the low-effort slay — you can load the driver as a module at boot time by putting this line in loader.conf(5):

if_otus_load="YES"

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🦋 DESCRIPTION 🦋

the otus driver supports USB 2.0 wireless network devices that are based on the Atheros AR9170 chipset. iconic. no cap.

the Atheros AR9170 is a draft-802.11n adapter that uses an external radio to operate in either 2.4GHz only, or 2.4GHz and 5GHz. so the chipset's the brain, the radio's the vibe. 🧚

• The AR9101 radio supports 1T1R operation in 2GHz only.
• The AR9102 radio supports 2T2R operation in 2GHz only.
• The AR9104 radio supports 2T2R operation both 2GHz and 5GHz.

these are the modes the otus driver can operate in:

BSS mode — also known as infrastructure mode, this is used when associating with an access point, through which all traffic passes. this mode is the default. she's the main character mode fr fr 👑

the otus driver can be configured to use Wired Equivalent Privacy (WEP) or Wi-Fi Protected Access (WPA-PSK and WPA2-PSK). WPA is the de facto encryption standard for wireless networks.

⚠️ it is strongly recommended that WEP not be used as the sole mechanism to secure wireless communication, due to serious weaknesses in it. like, it's giving "lock your door with a hair tie." please don't 😭

the otus driver can be configured at runtime with ifconfig(8). live your life, adjust your settings, we love a flexible icon.

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💖 HARDWARE 💖

the otus driver provides support for Atheros AR9170 USB IEEE 802.11b/g/n wireless network adapters, including:

• 3Com 3CRUSBN275
• Arcadyan WN7512
• CACE AirPcap Nx
• D-Link DWA-130 rev D1
• D-Link DWA-160 rev A1
• D-Link DWA-160 rev A2
• IO-Data WN-GDN/US2
• NEC Aterm WL300NU-G
• Netgear WNDA3100
• Netgear WN111 v2
• Planex GW-US300
• SMC Networks SMCWUSB-N2
• TP-Link TL-WN821N v1, v2
• Ubiquiti SR71 USB
• Unex DNUA-81
• Z-Com UB81
• Z-Com UB82
• ZyXEL NWD-271N

eighteen icons. the whole roster. ate. 🔥

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🎀 FILES 🎀

the driver needs at least version 1.0 of the following firmware files, which is loaded when an interface is attached:

/boot/kernel/otusfw-init.ko
/boot/kernel/otusfw-main.ko

like, both of them. don't skip leg day 🫶

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🌈 EXAMPLES 🌈

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

ifconfig wlan create wlandev otus0 inet 192.0.2.20/24

join a specific BSS network with network name my_net:

ifconfig wlan create wlandev otus0 ssid my_net up

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

ifconfig wlan create wlandev otus0 ssid my_net \
    wepmode on wepkey 0x1234567890 weptxkey 1 up

(that last one is for demonstration vibes only — remember the WEP warning up there, bestie 💀)

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🙈 DIAGNOSTICS 🙈

%s: failed load firmware of file otusfw-main

for some reason, the driver was unable to read the microcode file from the filesystem. the file might be missing or corrupted. so like… check your files, she's not being dramatic, the file genuinely isn't there 😭

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👑 SEE ALSO 👑

intro(1), netintro(4), otusfw(4), usb(4), wlan(4), arp(8), hostapd(8), ifconfig(8), wpa_supplicant(8)

the whole friend group. go read them, iykyk 💜

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⭐ HISTORY ⭐

the otus driver first appeared in OpenBSD 4.6 and FreeBSD 11. an elder. a legend. we stan a driver with lore 🌸

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🍓 AUTHORS 🍓

the otus driver was written by Damien Bergamini <damien@openbsd.org> and ported by Adrian Chadd <adrian@freebsd.org>. thank you kings 🫶

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💀 CAVEATS 💀

okay so this is the important part, bestie, listen up:

the otus driver only supports 802.11a/b/g operations. 802.11n operation is not supported at this time. so yes, the NAME section says a/b/g/n, but the n is aspirational. not me getting excited over nothing 😭

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and that's the page!! sign-off time: this was the OTUS(4) entry from Debian, dated November 10, 2024 — go forth and connect, bestie, mwah 💖✨