reserve_unaccepted(9)

✨ reserve_unaccepted(9): the Kernel API Manual glow-up ✨

okay so bestie, this is reserve_unaccepted from the Kernel API Manual — yes that's the manual name, we're not copying the header line, we're better than that 💅. Buckle up, this one's all about the unaccepted configuration table and making sure it gets mapped and reserved properly. no cap.

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🌸 SYNOPSIS 🌸

void reserve_unaccepted (struct efi_unaccepted_memory *unaccepted );

like, that's the whole signature. slay. ✨

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🎀 ARGUMENTS 🎀

• unaccepted — a pointer to the unaccepted memory table. that's it. that's the argument. she's got one job 🫶

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💖 DESCRIPTION 💖

okay so first things first: memblock_add makes sure that the table is mapped in direct mapping. iconic behavior honestly.

during a normal boot this whole thing just happens automatically, because the table gets allocated from usable memory — main character energy, it doesn't need help 🌈. but during crashkernel boot, only the memory that's specifically reserved for the crash scenario is mapped. so memblock_add is out here forcing the table to be mapped in the crashkernel case. lowkey a hero. 😭

then we align the range to the nearest page borders. ranges that are smaller than page size are not going to be mapped — so if your range is tiny, bestie, it's giving nothing, it's not getting mapped. periodt. 💀

and finally, memblock_reserve makes sure that future allocations will not touch the table. protecting her peace 🧚✨.

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🦋 SEE ALSO 🦋

• the kernel file ./drivers/firmware/efi/efi.c
• efi_mem_reserve(9)

go read those, iykyk 👑

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💜 no cap, if you skip the page-border alignment part, small ranges just won't get mapped — that's not me being dramatic, that's literally what the page says 🙈

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and that's the whole vibe check, bestie 🎀 — this lil beauty lives in ./drivers/firmware/efi, dated October 2026, and it's the reserve_unaccepted(9) page, so go forth and reserve your unaccepted stuff correctly fr fr 💅✨