libnvme(2)

✨ libnvme — section 2 of the manual, bestie ✨

okay so real talk: this is the libnvme API manual, section 2, and today we're hyperfixating on one (1) enum. it's giving "tiny struct field, enormous lore." let's get into it 💅

🌸 NAME 🌸

enum nvme_id_ctrl_bpcap — Boot Partition Capabilities. yes ma'am, that's the whole name. short. iconic. no notes.

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🎀 SYNOPSIS 🎀

enum nvme_id_ctrl_bpcap {
    NVME_CTRL_BACAP_RPMBBPWPS_SHIFT ,
    NVME_CTRL_BACAP_SFBPWPS_SHIFT ,
    NVME_CTRL_BACAP_RPMBBPWPS_MASK ,
    NVME_CTRL_BACAP_SFBPWPS_MASK ,
    NVME_CTRL_BACAP_RPMBBPWPS_NOT_SPECIFIED ,
    NVME_CTRL_BACAP_RPMBBPWPS_NOT_SUPPORTED ,
    NVME_CTRL_BACAP_RPMBBPWPS_SUPPORTED

};

like, look at her. seven whole constants. she ate and left no crumbs 🫶

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⭐ Constants ⭐

• NVME_CTRL_BACAP_RPMBBPWPS_SHIFT — this is the shift amount, bestie. you use it to get the RPMB Boot Partition Write Protection Support out of the struct nvme_id_ctrl.bpcap field. shifting is the move 🧚
• NVME_CTRL_BACAP_SFBPWPS_SHIFT — same energy, different feature: the shift amount to get the Set Features Boot Partition Write Protection Support</... wait, no, hold on — the Set Features Boot Partition Write Protection Support out of that same struct nvme_id_ctrl.bpcap field. one field, so much drama 😭
• NVME_CTRL_BACAP_RPMBBPWPS_MASK — the mask for getting the RPMB Boot Partition Write Protection Support from struct nvme_id_ctrl.bpcap. shift then mask. that's the ritual, iykyk 🔥
• NVME_CTRL_BACAP_SFBPWPS_MASK — the mask for getting the Set Features Boot Partition Write Protection Support from struct nvme_id_ctrl.bpcap. yes it's a whole parallel universe of constants, she's thorough 💜
• NVME_CTRL_BACAP_RPMBBPWPS_NOT_SPECIFIED — support for RPMB Boot Partition Write Protection is not specified. it's giving "we simply don't know, and that's valid." 🦋
• NVME_CTRL_BACAP_RPMBBPWPS_NOT_SUPPORTED — RPMB Boot Partition Write Protection is not supported by this controller. the controller said no 💀
• NVME_CTRL_BACAP_RPMBBPWPS_SUPPORTED — RPMB Boot Partition Write Protection is supported by this controller. we love a supportive controller. main character energy fr fr 👑

no cap, every single one of these is about reading bits out of the bpcap field of struct nvme_id_ctrl — some are shift amounts, some are masks, some are the actual values. don't mix 'em up or the vibe check will fail 🙈

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and that's the whole page, bestie 💖 this was enum nvme_id_ctrl_bpcap from libnvme(2), dated July 2026 — go forth, shift responsibly, and stan a well-documented bitfield ✨🎀