search_bbt(9)

💅 search_bbt(9) 💅

okay so welcome to the Kernel API Manual, bestie — today's main character is search_bbt(9), and it is lowkey iconic. it does a [GENERIC] scan of the device for a specific bad block table, and yes that is exactly as important as it sounds. 🦋✨

🌸 NAME 🌸

search_bbt — [GENERIC] scan the device for a specific bad block table. no cap, that's the whole assignment. 💖

🎀 SYNOPSIS 🎀

int search_bbt (struct nand_chip *this , uint8_t *buf , struct
nand_bbt_descr *td );

💖 ARGUMENTS 💖

• this — NAND chip object. the whole chip vibe. 👑
• buf — temporary buffer. think of it as the little tray you carry stuff around on. 🍓
• td — descriptor for the bad block table. the blueprint, the map, the moment. 🗺️

🦋 DESCRIPTION 🦋

okay so here's the tea: search_bbt() reads the bad block table by searching for a given ident pattern. the search is performed either from the beginning up or from the end of the device downwards — choose your adventure, bestie. the search starts always at the start of a block. that part is not negotiable. 💅

if the NAND_BBT_PERCHIP option is given, each chip is searched for a bbt, and that bbt contains the bad block information of this chip. this is necessary to provide support for certain DOC devices. so yeah, it's giving "per-chip main character energy" and it's doing it for a reason. 😭🔥

the bbt ident pattern resides in the oob area of the first page in a block. that's where the pattern lives. that's its home. 🏠✨

🌈 SEE ALSO 🌈

the kernel file is literally ./drivers/mtd/nand/raw/nand_bbt.c — yes bestie, that's the source file — and the whole friend group is:

• check_pattern(9)
• check_short_pattern(9)
• add_marker_len(9)
• read_bbt(9)
• read_abs_bbt(9)
• scan_read_oob(9)
• read_abs_bbts(9)
• create_bbt(9)
• search_read_bbts(9)
• get_bbt_block(9)
• mark_bbt_block_bad(9)
• write_bbt(9)
• nand_memory_bbt(9)
• check_create(9)
• nand_update_bbt(9)
• mark_bbt_region(9)
• verify_bbt_descr(9)
• nand_scan_bbt(9)
• nand_create_badblock_pattern(9)
• nand_create_bbt(9)
• nand_isreserved_bbt(9)
• nand_isbad_bbt(9)
• nand_markbad_bbt(9)

sign-off 💫 this page comes from the ./drivers/mtd/nand/raw source/version and is dated October 2026, and search_bbt(9) ate and left no crumbs. periodt. 🎀💜