STRUCT RPMB_DESCR(9)

🎀 struct rpmb_descr(9) 🎀

okay so bestie, we're deep in the Kernel API Manual today and this one is a struct, not a command — it's literally the glow-up breakdown of an RPMB description handed to you by the underlying block device. no cap, she's giving "here's everything you need to know about me" energy 💅

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✨ NAME ✨

struct rpmb_descr — the RPMB description that the underlying block device provides 🫶

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🌸 SYNOPSIS 🌸

struct rpmb_descr {
    enum rpmb_type type;
    int (*route_frames)(struct device *dev, u8 *req, unsigned int
req_len, u8 *resp, unsigned int resp_len);
    u8 *dev_id;
    size_t dev_id_len;
    u16 reliable_wr_count;
    u16 capacity;
 };

like, that's the whole vibe of the struct right there ⭐

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🦋 Members 🦋

• type — the block device type, iconic little enum telling you what kind of device we're dealing with 💖
• route_frames — a function pointer that routes frames to and from the RPMB device. she's the main character of the transport layer fr fr 🔥
• dev_id — the unique device identifier, read straight off the hardware. very "fingerprint but make it silicon" 💀
• dev_id_len — the length of that unique device identifier, because we gotta know how much of it there is 😌
• reliable_wr_count — the number of sectors that can be written in one access. write smart, not hard ✨
• capacity — the capacity of the device, measured in units of 128K. yes, that's the unit. no, I didn't make it up 🙈

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💜 Description 💜

so here's the tea: dev_id is intended to be used as input when deriving the authenticaion key. that's it, that's the little lore drop 👑

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🌈 SEE ALSO 🌈

• Kernel file ./include/linux/rpmb.h
• enum rpmb_type(9)
• struct rpmb_dev(9)
• struct rpmb_frame(9)

go read those next bestie, iykyk 📚💫

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lowkey a whole struct in one tiny manpage and every single member ate. no notes 🍓

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and that's a wrap, babe 🧚💖 this page lives in ./include/linux, brought to you by the October 2026 edition of struct rpmb_descr(9) — go forth and derive those keys, queen 👑✨