FDTBUS(4)

📦 version 15.1, in freebsd 14.5, freebsd 15.1, nixpkgs unstable

💅 FDTBUS(4) — like, the Flattened Device Tree bus driver, bestie

okay so real quick — this is fdtbus(4) from the Kernel Interfaces Manual, and it's genuinely one of those pages that sounds scary and then turns out to be the ✨glue✨ holding everything together. buckle up 🎀

🌸 NAME 🌸

fdtbus — the Flattened Device Tree bus driver. that's it, that's the name, she's iconic 💅

✨ SYNOPSIS ✨

options FDT

that's the whole vibe check right there. one line. no cap.

🦋 DESCRIPTION 🦋

so the fdtbus abstract bus driver is literally the primary connection and translation layer between the fdt(4) hardware resources description and the FreeBSD native newbus device drivers framework. like, she's the middleman. the translator. the friend who knows both groups at the party and introduces them 🫶

for an embedded system, fdtbus represents peripherals typically found on a highly integrated chip — aka a system-on-chip. yes, the whole chip. she contains multitudes 💜

the fdtbus driver provides generic, common infrastructure for all fdt(4)-oriented device drivers, and her main responsibilities are, in no particular order but also very much in this order:

  • Creating newbus children that reflect fdt(4) nodes in the flattened device tree 🌳 (she's literally making babies. newbus babies.)
  • Managing SYS_RES_IRQ resources ⚡
  • Managing SYS_RES_MEMORY, SYS_RES_IOPORT resources 🧠

three jobs, zero complaints, main character energy fr fr 👑

🔥 SEE ALSO 🔥

go read them, iyk yk 💖

🎀 STANDARDS 🎀

  • IEEE Std 1275: IEEE Standard for Boot (Initialization Configuration) Firmware: Core Requirements and Practices (Open Firmware).
  • Power.org Standard for Embedded Power Architecture Platform Requirements (ePAPR).

yes, she's standards-compliant. two of them. overachiever behavior ✨

⭐ HISTORY ⭐

the fdtbus support first appeared in FreeBSD 9.0. a legend was born 🌈

🌸 AUTHORS 🌸

the fdtbus support was developed by Semihalf under sponsorship from the FreeBSD Foundation. this manual page was written by Rafal Jaworowski. shoutout to the whole team, absolute icons 🫶💅

okay bestie that's the page!! one last thing though — the footer says this is from Debian, dated July 12, 2010, and the page itself is FDTBUS(4). so like, remember the date, remember the distro, and remember that she slayed before most of us were even on the internet 😭💖👑

📦 where this page comes from