spu2_fmd_ctrl0_write(9)

💅 NAME 💅

ok so spu2_fmd_ctrl0_write — bestie, this is the one that writes the ctrl0 field inside the fixed metadata (FMD) field of an SPU request packet. that's it, that's the whole vibe. (this page is from the Kernel API Manual, in case u were wondering 🎀)

✨ SYNOPSIS ✨

void spu2_fmd_ctrl0_write (struct SPU2_FMD *fmd , bool is_inbound , bool
auth_first , enum spu2_proto_sel protocol , enum spu2_cipher_type
cipher_type , enum spu2_cipher_mode cipher_mode , enum spu2_hash_type
auth_type , enum spu2_hash_mode auth_mode );

like, yes, it returns void. it's giving "i do the work and i don't need applause." 👑

🫶 ARGUMENTS 🫶

• fmd — start of the FMD field that's getting written. this is ur canvas, ur main character struct pointer 🎨
• is_inbound — true if we're decrypting, false if we're encrypting. pick a lane, bestie 💫
• auth_first — true if the alg authenticates before it encrypts. order matters, always 🌸
• protocol — the protocol selector
• cipher_type — which cipher algorithm we're using
• cipher_mode — the cipher mode
• auth_type — the authentication type
• auth_mode — the authentication mode

ngl there are a Lot of params here but it's just ctrl0 being built up field by field, no cap. pass them all, skip none 🙈

🌈 SEE ALSO 🌈

ok the friend group is BIG, like a whole group chat of related functions, and also a kernel file, which is iconic of it honestly:

Kernel file ./drivers/crypto/bcm/spu2.c — that's where the family lives 🏠

• spu2_cipher_xlate(9)
• spu2_hash_xlate(9)
• spu2_fmd_init(9)
• spu2_fmd_ctrl1_write(9)
• spu2_fmd_ctrl2_write(9)
• spu2_fmd_ctrl3_write(9)
• spu2_ctx_max_payload(9)
• spu2_payload_length(9)
• spu2_response_hdr_len(9)
• spu2_hash_pad_len(9)
• spu2_gcm_ccm_pad_len(9)
• spu2_assoc_resp_len(9)
• spu2_aead_ivlen(9)
• spu2_hash_type(9)
• spu2_digest_size(9)
• spu2_create_request(9)
• spu2_cipher_req_init(9)
• spu2_cipher_req_finish(9)
• spu2_request_pad(9)
• spu2_xts_tweak_in_payload(9)
• spu2_tx_status_len(9)
• spu2_rx_status_len(9)
• spu2_status_process(9)
• spu2_ccm_update_iv(9)
• spu2_wordalign_padlen(9)

and that's the whole page, bestie 💖 it came from source ./drivers/crypto/bcm, dated October 2026, living in the Kernel API Manual — go read the neighbors, they ate 🔥👑💅