Is there any plan to adopt devtmpfs ?

CyberLeo Kitsana cyberleo at
Thu Mar 5 17:07:56 UTC 2015

On 03/05/2015 09:38 AM, Manish Jain wrote:
> Hi all,
> I love FreeBSD, and a lot of people whom I have shown my box to have
> taken a fancy. It was with a lot of expectation that I downloaded and
> installed freebsd-10.1-i386. The system was likable enough, till I found
> a lot of hardware would not work - my canon printer gets detected in
> dmesg, but cups cannot locate any local printer; my APC UPS is able to
> perform a self test but is unable to shut down the system in case of a
> power outage on account of some communication failure re battery levels;
> and finally my keyboard stops responding. All these are USB devices, and
> I for some time believed that there might some problem with the USB stack.

Can you provide further details for these failures? Specific device
models and relevant dmesg(8) and usbconfig(8) output, for example.

> Just for kicks, I decided to try Linux to see if my stuff works. On
> Debian 7.8, neither the printer works nor does the UPS. However, with
> Ubuntu 14.10 the printer detection and installation was a cinch. I did
> not test the UPS, but I am sure that would have worked too - but the
> Unity desktop is too painful for me to verify this fully.

Linux and FreeBSD have, for the most part, completely different driver
and framework implementations. That your hardware works in one and not
the other merely indicates that it is probably a deficiency in the
FreeBSD drivers. That's fairly common for consumer-grade equipment,
given the relative sizes of the two projects and that, due to technical
and legal reasons, work cannot flow easily between the two.

> The one thing I noticed about Ubuntu 14.10 is that it uses a lot of
> virtual filesystems, headed by devtmpfs. Is it possible that a lot of
> hardware that currently is not working smoothly on FreeBSD will liven up
> simply by migrating one step ahead of devfs ? If yes, is there a
> possibility that we might be getting devtmpfs in 10.2/11.x ?

Ignoring obvious platform differences, the two are actually pretty much
identical in their operation. They are both virtual filesystems whose
contents are managed by the kernel, upon which permissions and ownership
are applied by a userland daemon according to rules specified by the

Neither of them have anything to do with the drivers that operate the
hardware; they merely provide management of the device nodes exposed by
those drivers.

Fuzzy love,
Technical Administrator
CyberLeo.Net Webhosting
<CyberLeo at CyberLeo.Net>

Furry Peace! -

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