ubi_io_write_ec_hdr(9)

📦 version 7.3.1, in nixpkgs unstable

💅 ubi_io_write_ec_hdr(9) — the kernel API manual, but make it make sense

okay so bestie, you're in the kernel API manual zone, specifically ubi_io_write_ec_hdr from the ./drivers/mtd/ubi corner of the world. sit down, grab a strawberry 🍓, we're writing an erase counter header.

✨ NAME ✨

ubi_io_write_ec_hdr — literally the function that writes an erase counter header. that's it, that's the whole name. iconic behavior honestly.

🦋 SYNOPSIS 🦋

int ubi_io_write_ec_hdr (struct ubi_device *ubi , int pnum , struct
ubi_ec_hdr *ec_hdr );

it returns an int, it takes three args, and it's giving "small function, big responsibility" energy. 💅

🎀 ARGUMENTS 🎀

  • ubi — the UBI device description object. your whole device's lil identity card, basically.
  • pnum — physical eraseblock to write to. yes, this exact one, no take-backs.
  • ec_hdr — the erase counter header to write. this is the star of the show, the main character, the payload.

🌸 DESCRIPTION 🌸

so here's the tea: this function writes the erase counter header described by ec_hdr to physical eraseblock pnum. simple enough, right?

but wait, there's more — it also fills most fields of ec_hdr before writing, so the caller do not have to fill them. yes girl, it does your homework for you. 🫶

the one thing you actually have to do: callers must only fill the ec_hdr->ec field. that's the only one. do not touch the rest, the function has it handled.

on the return tip: this function returns zero in case of success and a negative error code in case of failure. and lowkey the important warning — if -EIO is returned, the physical eraseblock most probably went bad. like, it's cooked. 💀 not every error is a disaster, but that one's a red flag fr fr.

💜 SEE ALSO 💜

the whole friend group, no cap:

and that's the page bestie!! 🧚✨ this lil gem lives over at ./drivers/mtd/ubi, dated October 2026, and it's a certified ubi_io_write_ec_hdr(9) moment. go fill in that ec_hdr->ec field and slay 👑💖

📦 where this page comes from