pack_bits(9)

okay bestie, welcome to pack_bits(9) from the Kernel API Manual — it's giving tiny-but-mighty bit-packing energy, and yes, we're gonna get through every single detail together. 💅✨

✨ NAME ✨

pack_bits — pack bit fields end-to-end. that's the whole vibe: bit fields get packed end-to-end, and this little icon is the one holding the aux cord. 🎀

🧚 SYNOPSIS 🧚

this is the exact signature, bestie — don't let the pointer-to-pointer scare you:

void pack_bits (const struct ubifs_info *c , uint8_t **addr , int *pos ,
       uint32_t val , int nrbits );

🌸 ARGUMENTS 🌸

argument roll call, no cap:

• c — UBIFS file-system description object. literally the UBIFS file-system description object, the main-character context for the whole operation. 👑
• addr — address at which to pack (passed and next address returned). it goes in as your packing address, and the next address comes back out. 🫶
• pos — bit position at which to pack (passed and next position returned). bit position in, next position out — the relay baton of bit offsets. 🏃‍♀️
• val — value to pack. the actual value getting tucked into those bits. 🍓
• nrbits — number of bits of value to pack (1-32). the range is literally 1-32, so don't come for that boundary. ⭐

🦋 SEE ALSO 🦋

if you're deep in the LPT lore, the Kernel file ./fs/ubifs/lpt.c is right there with this whole squad: do_calc_lpt_geom(9), ubifs_calc_lpt_geom(9), calc_dflt_lpt_geom(9), ubifs_unpack_bits(9), ubifs_pack_pnode(9), ubifs_pack_nnode(9), ubifs_pack_ltab(9), ubifs_pack_lsave(9), ubifs_add_lpt_dirt(9), set_ltab(9), ubifs_add_nnode_dirt(9), add_pnode_dirt(9), calc_nnode_num(9), calc_nnode_num_from_parent(9), calc_pnode_num_from_parent(9), ubifs_create_dflt_lpt(9), update_cats(9), replace_cats(9), check_lpt_crc(9), check_lpt_type(9), unpack_pnode(9), ubifs_unpack_nnode(9), unpack_ltab(9), unpack_lsave(9), validate_nnode(9), validate_pnode(9), set_pnode_lnum(9), ubifs_read_nnode(9), read_pnode(9), read_ltab(9), read_lsave(9), ubifs_get_nnode(9), ubifs_get_pnode(9), ubifs_pnode_lookup(9), ubifs_lpt_lookup(9), dirty_cow_nnode(9), dirty_cow_pnode(9), ubifs_lpt_lookup_dirty(9), ubifs_lpt_calc_hash(9), lpt_check_hash(9), lpt_init_rd(9), lpt_init_wr(9), ubifs_lpt_init(9), struct lpt_scan_node(9), scan_get_nnode(9), scan_get_pnode(9), ubifs_lpt_scan_nolock(9), dbg_chk_pnode(9), dbg_check_lpt_nodes(9).

okay that's the whole page, bestie — source is ./fs/ubifs, date is October 2026, and this pack_bits(9) manual is signing off with main-character energy. 🫶💖