STRUCT PERSISTENT_RAM_BUFFER(9)

✨ NAME ✨

struct persistent_ram_buffer — the persistent circular RAM buffer, bestie 💫

So there's this struct, right, and it's literally a ring buffer that lives in RAM that persists across reboots. Iconic behaviour, no cap.

🌸 SYNOPSIS 🌸

struct persistent_ram_buffer {
    uint32_t sig;
    atomic_t start;
    atomic_t size;
    uint8_t data[];
};

That's the whole vibe. Four members, one of them is a flexible array, she's giving main character energy 🎀

🎀 Members 🎀

Okay so let's meet the members one by one, they all ate:

• sig — the signature that says "yes queen, this is a header" (it's PERSISTENT_RAM_SIG xor a PRZ-type value) 🔥 It's a uint32_t, so keep it exact please.
• start — the first valid byte in the buffer. That's her position. atomic_t, so she's thread-safe about it 💅
• size — how many valid bytes are actually in the buffer. Also atomic_t. Literally the count of the real ones 🫶
• data — the contents of the buffer. That's the actual payload, the uint8_t[] flexible array doing all the heavy lifting ✨

🦋 SEE ALSO 🦋

• Kernel file ./fs/pstore/ram_core.c — go read the source, iykyk 💜

Heads up bestie: sig isn't just any old number — it's PERSISTENT_RAM_SIG xor a PRZ-type value, so don't go inventing your own and expecting the kernel to vibe check it as valid 🙈

Okay that's the whole page, so proud of you for reading it 🧚 From ./fs/pstore, the October 2026 era, section 9 of the Kernel API Manual — mwah, slay, periodt 💖⭐🌈