register_chrdev_region(9)

📦 version 7.3.1, in nixpkgs unstable

💖 register_chrdev_region(9) — the kernel API manual, bestie edition 🎀

okay so this one lives in the Kernel API Manual (section 9, iykyk) and it's genuinely one of those pages you'll want bookmarked, because it's the "grab your device numbers the polite way" function. let's get into it 💅

✨ NAME ✨

register_chrdev_region — register a range of device numbers 🎟️

like, a whole range. not just one. a little squad of device numbers, all registered together. slay.

🌸 SYNOPSIS 🌸

int register_chrdev_region (dev_t from , unsigned count , const char
*name );

that's three arguments, one int coming back at you, and yes the return value is the whole plot of this manpage 💀

🦋 ARGUMENTS 🦋

  • from — the first in the desired range of device numbers. heads up, bestie: it must include the major number. that's not optional, that's the vibe check 🫶
  • count — the number of consecutive device numbers required. how many friends are you bringing to the function 🎀
  • name — the name of the device or driver. this is what it'll be called. name your child wisely ✨

💜 DESCRIPTION 💜

so here's the tea, and honestly it's a short one:

the return value is zero on success, and a negative error code on failure. that's it. that's the whole description. no cap. 😭

so like — 0 means you ate and left no crumbs 👑, and anything negative means something went sideways and you gotta go read your errno. the manpage doesn't elaborate further, so neither will I, bestie. we respect the source. 🌈

⭐ SEE ALSO ⭐

the whole extended friend group, all referenced from the kernel file ./fs/char_dev.c 📁:

that's the full list, every single one, go read them when you're done here 🧚

little reminder 💀 — from must include the major number. I said it once in ARGUMENTS and I'm saying it again because this is the kind of thing that ruins your whole afternoon if you forget it. 🍓

and that's the page!! sourced from ./fs, dated October 2026, and it goes out as register_chrdev_region(9). mwah 💋 go register those regions, bestie — you're gonna do iconic things 🌟💖

📦 where this page comes from