Re: Getting request_firmware() filename info from user space

[Clemens Ladisch <clemens@ladisch.de>]

Peter Hsiang wrote:
> Using the kernel request_firmware() function, it seems one can send any file by:
>     cat myfile.bin > /sys/class/firmware/xxxx/data
> 
> How does the user space code obtain the filename parameter specified in the request_firmware() call?
> 
> The documentation says $DEVPATH and $FIRMWARE variables are provided in
> the environment, but "echo $FIRMWARE" prints an empty string.

drivers/base/firmware_class.c has:

static int firmware_uevent(struct device *dev, struct kobj_uevent_env *env)
{
	struct firmware_priv *fw_priv = to_firmware_priv(dev);

	if (add_uevent_var(env, "FIRMWARE=%s", fw_priv->fw_id))
		return -ENOMEM;
	if (add_uevent_var(env, "TIMEOUT=%i", loading_timeout))
		return -ENOMEM;
	if (add_uevent_var(env, "ASYNC=%d", fw_priv->nowait))
		return -ENOMEM;

	return 0;
}

Are these available at least in the udev rule?


Regards,
Clemens