__efi_memmap_init(9)

💅 __efi_memmap_init 💅

okay so bestie, welcome to the Kernel API Manual entry for __efi_memmap_init — she's the common-code girlie for mapping the EFI memory map, and honestly she ate. let's get into it 🫶

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✨ NAME ✨

__efi_memmap_init — the common code that handles mapping the EFI memory map. no cap, that's her whole job 💖

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🦋 SYNOPSIS 🦋

int __efi_memmap_init (struct efi_memory_map_data *data );

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💜 ARGUMENTS 💜

• data — the EFI memory map data 🎀 literally the whole memory map vibe lives in here

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🎀 DESCRIPTION 🎀

so here's the tea ☕ — this function is the one that figures out which function to use to map the EFI memory map inside efi.memmap, and it makes that call based on how far into the boot we are. yeah. she's reading the room. main character energy fr fr 👑

during bootup, EFI_MEMMAP_LATE in data->flags should be clear, because at that point the only things we have access to are the early_memremap*() functions — the vmalloc space isn't set up yet, so like, it's not available. periodt 💀 no vmalloc, no fancy options.

once the kernel is fully booted though? then we can fallback to the more robust memremap*() API. glow-up complete ✨ like she literally leveled up the mapping situation the moment the kernel finished booting 🧚

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🔥 RETURN 🔥

• zero on success 🎉 slay
• a negative error code on failure 😭 so if you see a negative number, that's your sign something did not go off

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🌈 SEE ALSO 🌈

• Kernel file ./drivers/firmware/efi/memmap.c — go read the source, iykyk 🦋
• efi_memmap_init_early(9) — the early-boot bestie 🌸
• efi_memmap_init_late(9) — the fully-booted bestie 💫

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and that's the page!! mwah 💋 built from ./drivers/firmware/efi, dated October 2026, and her name is __efi_memmap_init(9) in case you forgot already 🙈 — k bye, go map some memory responsibly 💅🌟