of_fdt_unflatten_tree(9)

💅 of_fdt_unflatten_tree(9) — the Kernel API Manual glow-up ✨

okay so bestie, welcome to the Kernel API Manual entry for of_fdt_unflatten_tree(9). yes the manual name is literally that, we're folding it in like a cute little name tag 🎀 this whole page is about turning a squished-flat device tree blob into an actual tree you can walk around in. iconic behaviour, honestly.

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🌸 NAME 🌸

of_fdt_unflatten_tree — create tree of device_nodes from flat blob

like… the whole gig. flat blob goes in, tree of device_nodes comes out. no cap 🦋

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✨ SYNOPSIS ✨

void * of_fdt_unflatten_tree (const unsigned long *blob , struct
       device_node *dad , struct device_node **mynodes );

three args, one pointer coming back at you. eat it up 🔥

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🎀 ARGUMENTS 🎀

• blob — Flat device tree blob. this is the squished one, the unflattened rawness, the before-picture 💀
• dad — Parent device node. yes, dad. the father node. the one it gets attached under 🫶
• mynodes — The device tree created by the call. this is where the output goes, it's an out-param bestie, watch it 🔥

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🦋 DESCRIPTION 🦋

okay so what this does is it unflattens the device-tree that got passed over by the firmware — literally takes the flat version and creates the tree of struct device_node. the way that this is the main character function of the whole file, honestly 👑

and it doesn't stop there — it also fills the "name" and "type" pointers of the nodes so that the normal device-tree walking functions can be used. so like, all the standard walking stuff just works afterwards. no extra setup, no vibes check, it just works. periodt 💅

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⭐ RETURN ⭐

• NULL on failure 😭
• or — on success — the memory chunk containing the unflattened device tree 💖

that's it. two outcomes. very binary of it.

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💜 SEE ALSO 💜

lowkey the whole friend group is here, all in the Kernel file ./drivers/of/fdt.c:

• unflatten_dt_nodes(9)
• __unflatten_device_tree(9)
• early_init_fdt_scan_reserved_mem(9)
• early_init_fdt_reserve_self(9)
• of_scan_flat_dt(9)
• of_scan_flat_dt_subnodes(9)
• of_get_flat_dt_subnode_by_name(9)
• of_fdt_is_compatible(9)
• of_flat_dt_is_compatible(9)
• of_flat_dt_match_machine(9)
• early_init_dt_check_for_initrd(9)
• early_init_dt_check_for_elfcorehdr(9)
• early_init_dt_check_for_usable_mem_range(9)
• early_init_dt_check_kho(9)
• unflatten_device_tree(9)
• unflatten_and_copy_device_tree(9)

read them all, iykyk 🌈

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real talk bestie: if it returns NULL, that's failure — don't go dereferencing the void, that's not the vibe 🙈

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and that's the page!! 🎀 sourced from ./drivers/of — October 2026 edition, and yes of_fdt_unflatten_tree(9) is the title of the whole thing, we're just ending on a cute sign-off. go unflatten some trees bestie, slay 💖✨🌸