add_usable_mem(9)

💖 add_usable_mem(9) 💖

ok so this is a page from the Kernel API Manual (section 9, the kernel-functions girlypop section, iykyk) and honestly? it's a little one but she's doing her job. let's get into it ✨

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🌸 NAME 🌸

add_usable_mem — literally the function that adds the usable memory ranges within the given memory range to the buffer. that's it, that's the whole vibe. no cap. 🫶

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🦋 SYNOPSIS 🦋

int add_usable_mem (struct umem_info *um_info , u64 base , u64 end );

like she takes three things and she returns an int. iconic behavior tbh 💅

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🎀 ARGUMENTS 🎀

• um_info — the usable memory buffer and the ranges info. she's carrying both, main character energy fr fr 👑
• base — base address of the memory range you wanna look for. the starting point bestie 💜
• end — end address of the memory range you wanna look for. the finish line 🏁

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⭐ DESCRIPTION ⭐

Returns 0 on success. Returns a negative errno on error. that's genuinely the whole description, she's a short queen and we respect that 🙈💖

ok lowkey important: on error it's a negative errno, not some random positive number. don't be out here misreading it, bestie 😭

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🌈 SEE ALSO 🌈

the whole friend group, in order, no one left out 🫶:

• Kernel file ./arch/powerpc/kexec/file_load_64.c — go read her, she's the source of truth 📖
• check_realloc_usable_mem(9)
• kdump_setup_usable_lmb(9)
• add_usable_mem_property(9)
• update_usable_mem_fdt(9)
• load_backup_segment(9)
• load_elfcorehdr_segment(9)
• load_crashdump_segments_ppc64(9)
• setup_purgatory_ppc64(9)
• cpu_node_size(9)
• kexec_extra_fdt_size_ppc64(9)
• setup_new_fdt_ppc64(9)
• arch_kexec_kernel_image_probe(9)
• arch_kimage_file_post_load_cleanup(9)

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💀 warning-ish note from me to you: every one of those is (9), so they're all kernel functions, not commands. don't go typing them into your shell, bestie, that's not the move 🙈

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and that's the page!! mwah 💋

source: ./arch/powerpc/kexec · dated October 2026 · go off, kexec file loader, you ate 🎀✨🦋💅