STRUCT OPTEE_MSG_PARAM(9)

💅 struct optee_msg_param(9) — Kernel API Manual 🎀

okay bestie, welcome to the glow-up era of kernel docs. this is the page for struct optee_msg_param, which is literally the parameter struct you use together with struct optee_msg_arg. they're a package deal, iykyk 🫶

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✨ NAME ✨

struct optee_msg_param — the parameter that gets used together with struct optee_msg_arg, fr fr 💖

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🌸 SYNOPSIS 🌸

here's the whole vibe, verbatim, no cap:

struct optee_msg_param {
    u64 attr;
    union {
      struct optee_msg_param_tmem tmem;
      struct optee_msg_param_rmem rmem;
      struct optee_msg_param_fmem fmem;
      struct optee_msg_param_value value;
      u8 octets[24];
    } u;
 };

look at her. iconic. the union is doing main character energy and we love that for her 👑

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🦋 Members 🦋

• attr — the attributes, bestie. this is the field that tells you what kind of thing you're looking at 💅
• u — the union that holds the OP-TEE msg parameter. she's flexible, she contains multitudes, she's literally holding all the possibilities at once 🎀

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⭐ Description ⭐

okay so here's the tea, and this part actually matters so pay attention 🙈

attr & OPTEE_MSG_ATTR_TYPE_MASK is what tells you if tmem, rmem, or value is the one being used in the union. it's the vibe check for the whole struct, honestly.

• OPTEE_MSG_ATTR_TYPE_VALUE_* → means it's value or octets
• OPTEE_MSG_ATTR_TYPE_TMEM_* → means it's tmem
• OPTEE_MSG_ATTR_TYPE_RMEM_* or the alias PTEE_MSG_ATTR_TYPE_FMEM_* → means it's rmem or fmem, depending on the conduit
• OPTEE_MSG_ATTR_TYPE_NONE → means literally none of the members are used. she's empty. she's resting. respect it 😌

heads up bestie: don't just assume which union member is live — the attr mask is the only thing that tells you. and for the RMEM_* / FMEM_* situation, the conduit is what decides. no guessing 🔥

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👑 SEE ALSO 👑

go read these next, they're all in the same friend group:

• Kernel file ./drivers/tee/optee/optee_msg.h struct
• struct optee_msg_param_tmem(9)
• struct optee_msg_param_rmem(9)
• struct optee_msg_param_fmem(9)
• struct optee_msg_param_value(9)
• struct optee_msg_arg(9)
• OPTEE_MSG_GET_ARG_SIZE(9)

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and that's the whole page, bestie, you ate 💅✨ this came to you from ./drivers/tee/optee, dated October 2026 — mwah, go slay your driver code 🧚💜