Re: [PATCH] firmware_loader: Expose requested firmware names as sysfs entries

["Danilo Krummrich" <dakr@kernel.org>]

(Cc: Corentin)

On Sat Oct 17, 2026 at 4:27 PM CEST, Javier Martinez Canillas wrote:
> Most initramfs image creation tools (e.g., dracut or initramfs-tools) have
> options to create initramfs images that are either generic or tailored to
> a running system. For example, dracut has the --host-only option for this.
>
> That option allows to have a smaller initramfs image which only contains a
> sub-set of the kernel modules, libraries, binaries and configuration data.
>
> One thing that can't be queried in a running system is the set of firmware
> names that were requested by the kernel to support the different devices.
>
> Let's expose this information as sysfs entries to allow initramfs creation
> tools to determine the set of firmware names that are needed by a system.
>
> On an AM625 BeaglePlay board, the following will be exposed through sysfs:
>
>   $ grep -H . /sys/class/firmware/requested*
>   /sys/class/firmware/requested0:powervr/rogue_33.15.11.3_v1.fw
>   /sys/class/firmware/requested1:ath3k-1.fw
>   /sys/class/firmware/requested2:regulatory.db
>   /sys/class/firmware/requested3:regulatory.db.p7s
>   /sys/class/firmware/requested4:ti-connectivity/wl1271-nvs.bin
>   /sys/class/firmware/requested5:ti-connectivity/wl18xx-conf.bin
>   /sys/class/firmware/requested6:ti-connectivity/wl18xx-fw-4.bin
>
> Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>

This was discussed before in [1]. I rejected it back then because userspace can
already collect this information through existing interfaces.

However, I can see how having a queryable history could simplify automated
tooling like dracut. Has this been discussed with the dracut maintainers, and is
there a concrete plan to use this interface?

[1] https://lore.kernel.org/all/20260715131325.26099-1-clabbe@baylibre.com/