Re: [PATCH v3 1/2] of: create of_root if no dtb provided

[Rob Herring]

On Thu, Feb 23, 2023 at 3:34 PM Frank Rowand <frowand.list@xxxxxxxxx> wrote:
>
> When enabling CONFIG_OF on a platform where of_root is not populated by
> firmware, we end up without a root node. In order to apply overlays and
> create subnodes of the root node, we need one. Create this root node
> by unflattening an empty builtin dtb.
>
> If firmware provides a flattened device tree (FDT) then the FDT is
> unflattened via setup_arch().  Otherwise, setup_of() which is called
> immediately after setup_arch(), and will create the default root node
> if it does not exist.

Why do we need a hook after setup_arch() rather than an initcall?

Rob