overlay_upd...l_references(9)

💅 overlay_update_local_references — Kernel API Manual ✨

ok so bestie, we're in the Kernel API Manual today and the star of the show is overlay_update_local_references(9). it's giving device-tree-glow-up energy and honestly? obsessed. let's get into it 🎀

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✨ NAME ✨

overlay_update_local_references — adjusts the overlay references 🦋

like, it literally goes in and nudges your references so everything lines up. no cap.

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🌸 SYNOPSIS 🌸

int overlay_update_local_references (void *fdto , uint32_t delta );

yes queen, two arguments, one int coming back at you. periodt.

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🫶 ARGUMENTS 🫶

• fdto — the device tree overlay blob 💖 (this is your whole overlay situation, the actual blob, main character)
• delta — the offset to shift the phandles of 🌈 (how much you're moving them by, fr fr)

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👑 DESCRIPTION 👑

okay so here's the tea ☕ — overlay_update_local_references updates all the phandles pointing to a node within the device tree overlay by adding a constant delta, so they don't conflict with the base overlay. like, it's out here doing a whole group-chat-wide update, every single phandle that points to one of those nodes, all of them, no one left on read 💅

highkey this is mainly used as part of a device tree application process — you know, the part where you want the device tree overlay's phandles to not conflict with the ones from the base device tree before merging them. that's the whole vibe check it's serving. ✨

lowkey important: the delta is constant and it gets added to the phandles — that's the mechanism, that's the move, that's the whole point 🔥

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⭐ RETURN ⭐

• 0 on success 🎉 (slay)
• negative error code on failure 😭 (it's giving not-iconic, check your error code)

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🧚 SEE ALSO 🧚

kernel file ./scripts/dtc/libfdt/fdt_overlay.c — go read it, iykyk 📖

and the whole friend group 💜:

• overlay_get_target_phandle(9)
• overlay_phandle_add_offset(9)
• overlay_adjust_node_phandles(9)
• overlay_adjust_local_phandles(9)
• overlay_update_local_node_references(9)
• overlay_fixup_one_phandle(9)
• overlay_fixup_phandle(9)
• overlay_fixup_phandles(9)
• overlay_adjust_local_conflicting_phandle(9)
• overlay_update_node_conflicting_references(9)
• overlay_update_local_conflicting_references(9)
• overlay_prevent_phandle_overwrite_node(9)
• overlay_prevent_phandle_overwrite(9)
• overlay_apply_node(9)
• overlay_merge(9)
• overlay_symbol_update(9)

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okay that's the whole page, go forth and merge those overlays responsibly 🍓

mwah 💋 — this lil page lives in ./scripts/dtc/libfdt, dated October 2026, and it's called overlay_upd...l_references(9) if you're looking it up later. bye bestie!! 🎀✨