Comments on: Module parameters from rc.conf in Arch

By: More goodies for ConnochaetOS « Motho ke motho ka botho

More goodies for ConnochaetOS « Motho ke motho ka botho — Sat, 06 Nov 2010 23:14:07 +0000

[...] — for reasons I don’t altogether understand — these Arch-based systems can get the framebuffer working with the tridentfb module, and a few [...]

By: K.Mandla

K.Mandla — Wed, 30 Jun 2010 22:22:44 +0000

That sounds like a good project for a talented Archer. I will probably surrender that idea to someone else though, because I don’t trust my infantile coding skills to work beyond the confines of my own home.

By: Devin

Devin — Wed, 30 Jun 2010 16:35:56 +0000

For some reason I doubt this is intended behavior… given the quality of their wiki, Arch has very few undocumented features. I still think this is a clever little hack though!

It works because /etc/rc.sysinit executes
/sbin/modprobe $mod
for each entry in MODULES instead of /sbin/modprobe "$mod"
so bash performs word splitting on the parameter expansion of $mod.

The caveat that should be mentioned is that this will only apply to the “Loading Modules” step at boot time. If you later remove and re-load a module with modprobe, any parameters you set here won’t take. This is probably why the /etc/modprobe.d method is recommended… it’s more likely always to work the way you expect (i.e. “the right way”), and it’s guaranteed not to break if the devs change the above-mentioned rc.sysinit line.

Cool idea though! If you like it, you could probably even modify the initscripts to autogenerate a custom modprobe.d file from these at bootup… submit a patch, who knows?

By: Adrian

Adrian — Sun, 20 Jun 2010 17:02:59 +0000

This is a good principle imho as rc.conf is Arch’s “control panel”, but much more sane.

By: Bryan

Bryan — Sat, 19 Jun 2010 14:26:48 +0000

I’ve never heard that this works. From what I’ve seen, most Archers suggest stuffing that into modprobe.d/{modulename}.conf, but it makes perfect sense that this should work. Good tip! Thanks