__of_overlay_apply_kunit(9)

💅 __of_overlay_apply_kunit — the Kernel API Manual, bestie edition ✨

okay so this is a page from the Kernel API Manual, and it's all about __of_overlay_apply_kunit — no cap, that double-underscore is doing main character energy 🌟

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🎀 NAME 🎀

__of_overlay_apply_kunit — the managed of_overlay_fdt_apply() variant, but make it a test 💖

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✨ SYNOPSIS ✨

int __of_overlay_apply_kunit (struct kunit *test , u8 *overlay_begin ,
const u8 *overlay_end );

like, that's the whole signature. slay 🫶

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🌸 ARGUMENTS 🌸

• test — the test context, literally the whole vibe of "which test am I" 🧚
• overlay_begin — start address of the overlay you're applying, iykyk ⭐
• overlay_end — end address of that same overlay, closing the range 🔥

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🦋 DESCRIPTION 🦋

okay so lowkey this is mostly internal API 🙈 — like, if you want the friendly version, go look at of_overlay_apply_kunit, that's the wrapper that makes this easier to use. bestie behaviour fr fr 💅

it's similar to of_overlay_fdt_apply, except the overlay is managed by the test case, and it gets automatically removed with of_overlay_remove after the test case concludes. so you don't have to clean up, it just handles itself, iconic 👑

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🌈 RETURN 🌈

• 0 on success — we love a win 💖
• a negative errno on failure — not me crying 😭

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🔥 SEE ALSO 🔥

• Kernel file ./include/kunit/of.h
• of_overlay_apply_kunit(9)

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💀 tiny little sign-off 💀

this whole page lives under ./include/kunit (that's the source, bestie), and it's dated October 2026 — so yeah, from the Kernel API Manual, with love 🌸🎀💜 periodt.