Re: [PATCH v3] Makefile: depend on OF_LIST dts sources for fit-dtb.blob

Hi Lianghong,

On 2026-07-23T01:40:21, Lianghong Liu <[email protected]> wrote:
> Makefile: depend on OF_LIST dts sources for fit-dtb.blob
>
> When CONFIG_MULTI_DTB_FIT is enabled, fit-dtb.blob is produced by
> mkimage with one "-b " argument for every entry in CONFIG_OF_LIST.
> The make rule, however, only listed dts/dt.dtb (i.e. the
> CONFIG_DEFAULT_DEVICE_TREE blob) as a prerequisite:
>
>   fit-dtb.blob: dts/dt.dtb FORCE
>       $(call if_changed,mkimage)
>
> Because FORCE is PHONY, if_changed ignores it and rebuilds only when
> any-prereq or arg-check is non-empty.  Editing a non-default dts in
> OF_LIST rebuilds its .dtb (tracked correctly via fixdep), but that
> .dtb was not a prerequisite of fit-dtb.blob, so $? stayed empty; the
> mkimage command line was unchanged too, so arg-check was empty as
> well.  if_changed therefore skipped mkimage and fit-dtb.blob kept the
> stale dtbs.  u-boot.bin, which appends fit-dtb.blob, then shipped the
> old device tree and the dts change did not take effect.
>
> A previous attempt to fix this added every OF_LIST .dtb *output* as a
> prerequisite.  That is wrong on two counts:

Thanks

Reviewed-by: Simon Glass <[email protected]>

Regards,
Simon