IT(4)

🎀 IT(4) — the temperature/voltage/fan-sensor-and-watchdog bestie 🎀

ok so real talk, this is the it page from the Kernel Interfaces Manual — she's a hardware-monitor driver and she's literally carrying the whole sensors game on her back, no cap 💅

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✨ NAME ✨

it — the driver for ITE IT87xxF and SiS SiS950 temperature, voltage, and fan sensors, and she also does watchdog timer duty 🐕🔥

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🦋 SYNOPSIS 🦋

it* at isa? port 0x2e
it* at isa? port 0x4e

two ports, that's the whole vibe check 🫶

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💖 DESCRIPTION 💖

okay so the it driver is out here providing support for the ITE IT8705F, IT8712F, IT8716F, IT8718F, IT8720F, IT8726F, IT8728F, IT8772F, and the SiS SiS950 hardware monitors — plus the watchdog(4) timer — and you talk to all of it through the sysctl(8) interface. slay 💅✨

Most of the supported devices are absolutely stacked with 17 sensors, and here's the full rundown so you know exactly what you're looking at 🧚‍♀️:

• temp0 — units uK — the classic: CPU Temperature 🔥
• temp1 — units uK — Motherboard Temperature
• temp2 — units uK — Unused (she's just there for the plot 💀)
• fan0 — units RPM — CPU Fan
• fan1 — units RPM — Chassis Fan
• fan2 — units RPM — Power Fan
• fan3 — units RPM — Unused
• fan4 — units RPM — Unused
• volt0 — units uV DC — Core voltage
• volt1 — units uV DC — Core voltage
• volt2 — units uV DC — +3.3V
• volt3 — units uV DC — +5V
• volt4 — units uV DC — +12V
• volt5 — units uV DC — -12V
• volt6 — units uV DC — -5V
• volt7 — units uV DC — +5VSB
• volt8 — units uV DC — VBAT

seventeen. sensors. main character energy fr fr 👑🌈

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🩷 SEE ALSO 🩷

isa(4), watchdog(4), sensorsd(8), sysctl(8), watchdogd(8) — go read those too, iykyk 📚✨

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🌸 HISTORY 🌸

The it driver first appeared in OpenBSD 3.4. a whole era 🕰️💜

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🫶 AUTHORS 🫶

The it driver was originally written for OpenBSD 3.4 by Julien Bordet <zejames@greyhats.org>, and then completely rewritten for OpenBSD 4.3 by Oleg Safiullin <form@pdp-11.org.ru>. glow-up of the century tbh ✨💅

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💀 BUGS 💀

ok so listen, two things, and they matter:

• Watchdog timer functionality is not supported for the ITE IT8705 or the SiS SiS950 chips. not a thing. don't ask 😭
• For older IT8712 chips, watchdog timeout values of more than 255 seconds are rounded up to the nearest minute. so like… she's approximating. heads up 🫠

ngl the rounding thing is the kind of detail that will bite you at 3am, so maybe double-check your timeouts bestie 🙈

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and that's the page!! written by the Debian crew, dated September 10, 2015, and honestly she still eats 💖🎀🦋 periodt ✨