SMBUS(4)

📦 version 12.2, in debian bookworm, debian trixie, ubuntu jammy, ubuntu noble, ubuntu questing, ubuntu resolute, ubuntu stonking

💖 SMBUS(4) 💖

okay bestie, gather round, because today we're learning about smbus — the System Management Bus — from the Kernel Interfaces Manual. yes it's a real manual page, yes it's from Debian, and yes it's lowkey iconic. let's go 🫶

✨ NAME ✨

smbus — System Management Bus

🌸 SYNOPSIS 🌸

device smbus

device iicsmb
device bktr

that's it, that's the whole vibe check. three little lines 💅

🦋 DESCRIPTION 🦋

so the smbus system is giving uniform, modular, and architecture-independent. the way it just doesn't care what architecture you're on?? main character energy fr fr. it exists so drivers can control all kinds of SMB devices, and so different SMB controllers can all do their thing — we're talking I2C, PIIX4, Brooktree848, vm86... the whole squad. ✨

🌈 System Management Bus 🌈

the System Management Bus is a two-wire interface that lets simple power-related chips talk to the rest of the system. it uses I2C as its backbone — peep iicbus(4) for that whole situation 👀

a system using SMB passes messages to and from devices instead of tripping individual control lines. no tripping, we're too classy for that 💅

with the SMBus, a device can:

  • provide manufacturer information 🏷️
  • tell the system what its model/part number is 🔢
  • save its state for a suspend event 💾
  • report different types of errors 😭
  • accept control parameters 🎛️
  • return its status 📊

and ngl, that's a whole personality. obsessed.

also!! the SMBus may share the same host device and physical bus as ACCESS bus components — provided that an appropriate electrical bridge is provided between the internal SMB devices and external ACCESS bus devices. so like, yes you can share, but you NEED the bridge. no bridge, no sharing, periodt. 🌉

👑 SEE ALSO 👑

and the SMBus specification itself, at http://www.smbus.org/specs/ — go read it if you want the full lore 📚

🎀 HISTORY 🎀

the smbus manual page first appeared in FreeBSD 3.0. a true legend from day one 💖

🧚 AUTHORS 🧚

this manual page was written by Nicolas Souchu. thank you for your service, king 🫡

cute lil sign-off: this page comes to you from the Debian crowd, dated August 10, 1998, and it's filed under SMBUS(4). oldie but a goodie, fr fr. byeeee 💜✨
📦 where this page comes from