validate_vid_hdr(9)

💅 validate_vid_hdr(9) — like, the volume identifier header check 🌸

okay so bestie, welcome to the validate_vid_hdr page from the Kernel API Manual (yes that's the manual name, i'm not being weird about it) — it lives in ./drivers/mtd/ubi and it's genuinely one of those tiny-but-iconic functions. let's get into it 🫶

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✨ NAME ✨

validate_vid_hdr — validate a volume identifier header. fr fr that's the whole vibe check. 🦋

✨ SYNOPSIS ✨

int validate_vid_hdr (const struct ubi_device *ubi , const struct
       ubi_vid_hdr *vid_hdr );

like yes, two args, returns an int, we love a simple signature 💖

✨ ARGUMENTS ✨

• ubi — the UBI device description object. this is your main character device, the one whose headers we're checking 🎀
• vid_hdr — the volume identifier header to check. the actual thing under the microscope 🔍

✨ DESCRIPTION ✨

so what does it do? this function checks that data stored in the volume identifier header vid_hdr. that's the whole job. no cap. 💅

and the return values? listen closely because this is the part everyone gets wrong:

• returns zero if the VID header is OK ✅
• returns 1 if it's not OK 💀

that's it. zero good, one bad. iconic behaviour, honestly.

✨ SEE ALSO ✨

the kernel file ./drivers/mtd/ubi/io.c is where the magic lives, and it's friends with literally everyone:

• ubi_io_read(9)
• ubi_io_write(9)
• do_sync_erase(9)
• torture_peb(9)
• nor_erase_prepare(9)
• ubi_io_sync_erase(9)
• ubi_io_is_bad(9)
• ubi_io_mark_bad(9)
• validate_ec_hdr(9)
• ubi_io_read_ec_hdr(9)
• ubi_io_write_ec_hdr(9)
• ubi_io_read_vid_hdr(9)
• ubi_io_write_vid_hdr(9)
• self_check_not_bad(9)
• self_check_ec_hdr(9)
• self_check_peb_ec_hdr(9)
• self_check_vid_hdr(9)
• self_check_peb_vid_hdr(9)
• self_check_write(9)
• ubi_self_check_all_ff(9)

go read them all bestie, i'll wait 🧚

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and that's the page!! mwah 💋 — sign-off time: this one's from ./drivers/mtd/ubi, dated October 2026, in the Kernel API Manual, and yes it's literally called validate_vid_hdr(9) 💜