Arch Linux

Wen

Member

From: Oslo, Norway

Registered: 2008-10-02

Posts: 40

Include wpa_supplicant into initram

Hi,

I use dm-encrypt to encrypt my home server. Sometimes it is neccessary to reboot my home server remotely. So I need to enable ssh server in initram. According to this web page, I can do so by including dropbear as ssh server.

However, the remote server only has wireless access to the Internet. Therefore, I will also need to include wpa_supplicant and a dhcp client. Is there some way to achieve it?

Thanks in advance!

WonderWoofy

Member

From: Los Gatos, CA

Registered: 2012-05-19

Posts: 8,414

Re: Include wpa_supplicant into initram

It would seem as though you would probably want to write up your own HOOK for this.  Because you will not only need wpa_supplicant and a dhcp client, but you will also need to have this connection process scripted in a hook (see /usr/lib/initpcio/hooks).  If you are using the systemd HOOK rather than base and udev, you will have to also include the systemd.unit files and have them linked into whatever the default.target is in the initramfs.

All in all, I think this is going to require that you start reading up quite a bit on mkinitcpio and try to wrap your head around how it all works.  What is kind of nice is that there is now an /etc/initcpio directory than can be used to drop in your own hooks and whatnot.

Wen

Member

From: Oslo, Norway

Registered: 2008-10-02

Posts: 40

Re: Include wpa_supplicant into initram

Hi WonderWoofy,

Thanks. That's too complicated for me. I'll have to manually reboot every time then.

WonderWoofy

Member

From: Los Gatos, CA

Registered: 2012-05-19

Posts: 8,414

Re: Include wpa_supplicant into initram

You might just take a look at what the nfs hooks do in mkinitcpio-nfs-utils to connect to the network.  I am pretty sure they only do wired connections, but it might be a good starting point to see how things are done.

I imagine that you will end up having to use the base and udev HOOKS simply because the dropbear_initrd_encrypt package only provides HOOKs for that option.  So it will really just be a matter of figuring out how to get the install file of the HOOK to add wpa_supplicant and ensure the wireless module in incuded.  Then have the hook file script out the connection. 

In any case, good luck!

Wen

Member

From: Oslo, Norway

Registered: 2008-10-02

Posts: 40

Re: Include wpa_supplicant into initram

Cool. Thanks a lot! :-)