ubi_io_write(9)

📦 version 7.3.1, in nixpkgs unstable

💖 ubi_io_write(9) 💖

okay so bestie, welcome to the Kernel API Manual — this is the page for ubi_io_write(9), and honestly? it's giving "tiny function, big responsibility." let's get into it ✨

✨ NAME ✨

ubi_io_write — write data to a physical eraseblock. that's it. that's the whole vibe. 🎀

🌸 SYNOPSIS 🌸

int ubi_io_write (struct ubi_device *ubi , const void *buf , int pnum ,
       int offset , int len );

literally just five things and a return type, no cap 🫶

🦋 ARGUMENTS 🦋

  • ubi — the UBI device description object. the whole main character of this operation tbh 👑
  • buf — buffer with the data to write. this is the stuff you're sending out into the world 💅
  • pnum — physical eraseblock number to write to. yes, the actual one you're targeting, not a vibe 👀
  • offset — offset within the physical eraseblock where to write. like, where inside the block. precision matters bestie 🎯
  • len — how many bytes to write. the length. the amount. the len. 😌

🔥 DESCRIPTION 🔥

so this function writes len bytes of data from buffer buf to offset offset of physical eraseblock pnum. that's the whole thing — write, bytes, offset, block. slay.

if all the data were successfully written, zero is returned. yes, 0 = we ate. 🌈

if an error occurred, this function returns a negative error code instead. and here's the part where you gotta pay attention:

if -EIO is returned, the physical eraseblock most probably went bad. 💀 like, it's cooked. it's not okay. it's giving hardware betrayal. ngl, that's a bad sign.

and also, one more thing that's genuinely important to know:

note, in case of an error, it is possible that something was still written to the flash media, but may be some garbage. 🙈 so like. the write failed but the flash still has... something. maybe. garbage. not your data, not useful data — garbage. this is the "we tried but the vibes were off" scenario, fr fr.

⭐ SEE ALSO ⭐

the whole friend group 💜 (kernel file ./drivers/mtd/ubi/io.c is where they all live, btw):

aaaand that's the page!! 🧚✨ cute sign-off time: this one lives in ./drivers/mtd/ubi and it's dated October 2026 — so go forth, write your bytes, check for -EIO, and don't trust a bad eraseblock. mwah 💋🍓

📦 where this page comes from