Enable configuration of usb_modeswitch, e. g. by adding an overlay to /etc/usb_modeswitch.d/

[herrernst]

Hi,

I'd like to use a Huawei 4G USB modem stick in CDC-NCM mode. On Debian Linux, this works by setting HuaweiAltModeGlobal=1 in /etc/usb_modeswitch.conf (or by adding a specific file in /etc/usb_modeswitch.d/). Unfortunately, these locations are not editable in HAOS. So I tried creating a udev rule in /etc/udev/rules.d/ (which is writable), but it seems usb_modeswitch is started by systemd when attaching the USB device before executing my rule (also, it's a bit of a workaround).

I see there are some locations on the rootfs for which there is a writable overlay (documented at Documentation/configuration.md#local and defined in *.mount files at usr/lib/systemd/system/).

Unless there are better ideas I would suggest adding an overlay mount like etc-udev-rules.d.mount for /etc/usb_modeswitch.d/, so it's possible to configure usb_modeswitch.

Thank you.

[sairon]

Yes, it's reasonable to make the directory writable, I created #3800 to make it possible.

[herrernst]

Great, thank you very much!