Re: [PATCH v4 07/11] of: overlay: add FIT image overlay support

[Marco Felsch <m.felsch@pengutronix.de>]

On 25-08-05, Sascha Hauer wrote:
> On Tue, Jul 29, 2025 at 05:34:32PM +0200, Marco Felsch wrote:
> > This adds the support to load devicetree overlays from a FIT image.
> > There are a few options to handle FIT overlays since the FIT overlay
> > spec is not very strict.
> > 
> > This implements the most configurable case where each overlay does have
> > its own config node (including the optional signature).
> > 
> > - The "pattern" filter matches the config-node names (the node names
> >   below the configurations node), not the overlay image names (the node
> >   names below the images node).
> > 
> > - The "compatible" filter check doesn't differ from the file based overlay
> >   handling.
> > 
> > Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
> > ---
> >  Documentation/user/devicetree.rst |  19 +++---
> >  drivers/of/overlay.c              | 132 +++++++++++++++++++++++++++++++++++---
> >  2 files changed, 134 insertions(+), 17 deletions(-)
> > 
> > diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c
> > index f02a12d44f0d53db3fb7bb065461c0ef193d0ab3..604ce0998cd8044cca59c40e65f4e9b95bec6112 100644
> > --- a/drivers/of/overlay.c
> > +++ b/drivers/of/overlay.c
> > @@ -8,10 +8,13 @@
> >   */
> >  #define pr_fmt(fmt) "of_overlay: " fmt
> >  
> > +#include <bootm.h>
> >  #include <common.h>
> >  #include <of.h>
> >  #include <errno.h>
> > +#include <filetype.h>
> >  #include <globalvar.h>
> > +#include <image-fit.h>
> >  #include <magicvar.h>
> >  #include <string.h>
> >  #include <libfile.h>
> > @@ -463,8 +466,99 @@ static int of_overlay_apply_dir(struct device_node *root, const char *dirname,
> >  	return ret;
> >  }
> >  
> > +static int of_overlay_apply_fit(struct device_node *root, struct fit_handle *fit,
> > +				struct device_node *config)
> > +{
> > +	const char *name = config->name;
> > +	struct device_node *overlay;
> > +	unsigned long ovl_sz;
> > +	const void *ovl;
> > +	int ret;
> > +
> > +	if (!of_overlay_matches_filter(name, NULL))
> > +		return 0;
> > +
> > +	ret = fit_open_image(fit, config, "fdt", &ovl, &ovl_sz);
> > +	if (ret)
> > +		return ret;
> > +
> > +	overlay = of_unflatten_dtb(ovl, ovl_sz);
> > +
> > +	if (!of_overlay_matches_filter(NULL, overlay)) {
> > +		ret = 0;
> > +		goto out;
> > +	}
> > +
> > +	ret = of_overlay_apply_tree(root, overlay);
> > +	if (ret == -ENODEV)
> > +		pr_debug("Not applied %s (not compatible)\n", name);
> > +	else if (ret)
> > +		pr_err("Cannot apply %s: %s\n", name, strerror(-ret));
> > +	else
> > +		pr_info("Applied %s\n", name);
> > +
> > +out:
> > +	of_delete_node(overlay);
> > +
> > +	return ret;
> > +}
> > +
> > +static bool of_overlay_valid_config(struct fit_handle *fit,
> > +				    struct device_node *config)
> > +{
> > +	/*
> > +	 * Either kernel or firmware is marked as mandatory by U-Boot
> > +	 * (doc/usage/fit/source_file_format.rst) except for overlays
> > +	 * (doc/usage/fit/overlay-fdt-boot.rst). Therefore we need to ensure
> > +	 * that only "fdt" config nodes are recognized as overlay config node.
> > +	 */
> > +	if (!fit_has_image(fit, config, "fdt") ||
> > +	    fit_has_image(fit, config, "kernel") ||
> > +	    fit_has_image(fit, config, "firmware"))
> > +		return false;
> > +
> > +	return true;
> > +}
> > +
> > +static int of_overlay_global_fixup_fit(struct device_node *root,
> > +				       const char *fit_path, loff_t fit_size)
> > +{
> > +	enum bootm_verify verify = bootm_get_verify_mode();
> > +	struct device_node *conf_node;
> > +	struct fit_handle *fit;
> > +	int ret;
> > +
> > +	if (!IS_ENABLED(CONFIG_FITIMAGE))
> > +		return 0;
> 
> The comments in https://lore.barebox.org/barebox/ZpT3h0o089tae2WS@pengutronix.de/
> do not seem to be addressed here.

Sorry, I missed your comments. I will answer them first on the old
Mail-Thread and send a new version afterwards.

Thanks,
  Marco

> 
> Sascha
> 
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