bug#22050: [PATCH v3 1/2] linux-boot: Add make-static-device-nodes.

[Danny Milosavljevic <dannym@scratchpost.org>]

Hi Ludo,

On Thu, 14 Dec 2017 14:14:09 +0100
ludo@gnu.org (Ludovic Courtès) wrote:

> The code would be slightly simpler (no pipe, etc.), and the .devname
> file might be more stable than the kmod output, being a kernel
> interface.
> 
> WDYT?

That's true.  The kernel interface definitely has Linus breathe down the neck of anyone who even thinks of changing it :)

> >> What about having a ‘static-device-nodes’ procedure that would parse
> >> that and return a list of <device-node>, where:
> >> 
> >>   ;; TYPE is 'char or 'block, MAJOR and MINOR are integers.
> >>   (define-record-type <device-node>
> >>     (device-node name type major minor module)
> >>     device-node?
> >>     …)
> >> 
> >> and then:
> >> 
> >>   (define create-device-node
> >>     (match-lambda
> >>       (($ <device-node> name type major minor)
> >>        (mknod …))))
> >> 
> >> finally:
> >> 
> >>   (for-each create-device-node (static-device-nodes))
> >> 
> >> ?  
> >
> > The kmod format has entries not only for mknod but also for mkdir (it actually mkdirs the same directory twice sometimes which is why there was another version of this patch...).  
> 
> OK, I had overlooked that.  Hopefully the general approach remains
> valid?

Yeah.  Apparently kmod autogenerates those when there's a slash in the name it got from the devname file.  That's why it generates two mkdir entries for "snd" - there's a "snd/timer" and a "snd/seq" in the devname file...