ubi_attach_mtd_dev(9)

📦 version 7.3.1, in nixpkgs unstable

✨ ubi_attach_mtd_dev(9) ✨

okay so bestie, welcome to the kernel API manual page for ubi_attach_mtd_dev — yes that's a 9 in the parens, it's a kernel function, we're in the big leagues now 💅

🎀 NAME 🎀

ubi_attach_mtd_dev — attach an MTD device. literally what it says on the tin 🫶

🌸 SYNOPSIS 🌸

int ubi_attach_mtd_dev (struct mtd_info *mtd , int ubi_num , int
       vid_hdr_offset , int max_beb_per1024 , bool disable_fm , bool
       need_resv_pool , int wl_threshold );

💖 ARGUMENTS 💖

so here's the whole cast of characters, no cap:

  • mtd — the MTD device description object. this is the actual device bestie, the whole point of the operation 🦋
  • ubi_num — the number you wanna assign to the brand new UBI device ✨
  • vid_hdr_offset — the VID header offset. that's it, that's the vibe 💅
  • max_beb_per1024 — the maximum expected number of bad PEB per 1024 PEBs. yeah, bad blocks happen, we plan for them 🙈
  • disable_fm — whether to disable fastmap. a lil boolean, lowkey important 🔥
  • need_resv_pool — whether to reserve pebs to fill fm_pool 🌸
  • wl_threshold — the wear-leveling threshold for this UBI device; 0 means use CONFIG_MTD_UBI_WL_THRESHOLD; accepted range is 2-65536. numbers, bestie, we love a range 🎀

👑 DESCRIPTION 👑

This function attaches MTD device mtd_dev to UBI and assigns ubi_num as the number of the newly created UBI device — unless ubi_num is UBI_DEV_NUM_AUTO, in which case this function goes looking for a vacant device number and assigns it automatically, main character energy fr fr ⭐

It returns the new UBI device number in case of success, and a negative error code in case of failure. slay when it works, 😭 when it doesn't.

If disable_fm is true, ubi doesn't create new fastmap — even the module param doing full scanning. not me pointing that out twice, it's literally in there 💀

⚠️ Note, the invocations of this function has to be serialized by the ubi_devices_mutex. do not skip this, bestie, that's a race condition waiting to happen 🫶

🌈 SEE ALSO 🌈

like, go read them, they're all iconic in their own way 👑

and that's the page, bestie 🧚 this little love letter lives in ./drivers/mtd/ubi, dated October 2026, and it's brought to you by ubi_attach_mtd_dev(9) — periodt 💜

📦 where this page comes from