From: Luca Ceresoli <luca@lucaceresoli.net>
To: buildroot@busybox.net
Subject: [Buildroot] [RFC 3/6] system: add mdev-only /dev management (without devtmpfs)
Date: Wed, 9 Sep 2015 14:29:36 +0200 [thread overview]
Message-ID: <55F02630.5050500@lucaceresoli.net> (raw)
In-Reply-To: <55EFF9FF.1020402@mind.be>
Dear Arnout,
Arnout Vandecappelle wrote:
> On 08-09-15 23:28, Luca Ceresoli wrote:
>> +++ b/package/busybox/inittab
>> @@ -16,6 +16,7 @@
>> # Startup the system
>> null::sysinit:/bin/mount -t proc proc /proc
>> null::sysinit:/bin/mount -t sysfs sysfs /sys
>> +#null::sysinit:/sbin/activate-mdev
>
> Excuse my stupidity, but wouldn't it be enough to add the following here:
>
> null::sysinit:/bin/mount -t tmpfs mdev /dev
>
> and keep on using S10mdev? That is less invasive, and it should work since it's
> more or less the same as what is done in the cpio/initramfs case.
Good idea, with a couple caveats.
The first problem is we'd have an empty /dev since the mount until the
execution of S10mdev. This prevents busybox init from executing all
lines in inittab after the mount, since they would try to open
/dev/null. Symptom: "can't open /dev/null: No such file or directory".
The fix should be simply:
-null::sysinit:/bin/mkdir -p /dev/pts
-null::sysinit:/bin/mkdir -p /dev/shm
-null::sysinit:/bin/mount -a
-null::sysinit:/bin/hostname -F /etc/hostname
+::sysinit:/bin/mkdir -p /dev/pts
+::sysinit:/bin/mkdir -p /dev/shm
+::sysinit:/bin/mount -a
+::sysinit:/bin/hostname -F /etc/hostname
Lines up to the /dev mount might be changed as well to have a more
uniform style, but it's not strictly needed.
I'll check if sysvinit init has any issues.
But ehen, if any user has an S05something that uses /dev, it would
break. In order to reduce the risk to nearly zero, we might move
S10mdev to S00mdev, so it runs (most likely) as the first script.
This would slightly change the current behaviour for all cases, and
start S01logging after mdev, not before. I tested it quickly and it
looks like it works. Can you think of any problem with moving S10mdev
to S00mdev?
--
Luca
next prev parent reply other threads:[~2015-09-09 12:29 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-08 21:28 [Buildroot] [RFC 0/6] mdev-only /dev management (without devtmpfs) Luca Ceresoli
2015-09-08 21:28 ` [Buildroot] [RFC 1/6] Move mounting /sys from fstab to inittab Luca Ceresoli
2015-09-09 9:12 ` Arnout Vandecappelle
2015-09-08 21:28 ` [Buildroot] [RFC 2/6] system: clarify /dev management using devtmpfs + {mdev, eudev} Luca Ceresoli
2015-09-09 9:40 ` Arnout Vandecappelle
2015-09-09 10:53 ` Luca Ceresoli
2015-09-09 10:54 ` Arnout Vandecappelle
2015-09-08 21:28 ` [Buildroot] [RFC 3/6] system: add mdev-only /dev management (without devtmpfs) Luca Ceresoli
2015-09-09 9:21 ` Arnout Vandecappelle
2015-09-09 12:29 ` Luca Ceresoli [this message]
2015-09-09 12:32 ` Arnout Vandecappelle
2015-09-09 13:54 ` Thomas Petazzoni
2015-09-14 13:47 ` Luca Ceresoli
2015-09-14 22:23 ` Arnout Vandecappelle
2015-09-15 22:35 ` Luca Ceresoli
2015-09-14 20:53 ` Peter Korsgaard
2015-09-14 21:34 ` Thomas Petazzoni
2015-09-14 21:38 ` Peter Korsgaard
2015-09-15 7:30 ` Thomas Petazzoni
2015-09-15 8:09 ` Peter Korsgaard
2015-09-15 9:41 ` Thomas Petazzoni
2015-09-15 12:01 ` Peter Korsgaard
2015-09-15 12:27 ` Arnout Vandecappelle
2015-09-15 12:32 ` Peter Korsgaard
2015-09-18 16:37 ` Luca Ceresoli
2015-09-15 13:03 ` Thomas Petazzoni
2015-09-15 13:14 ` Peter Korsgaard
2015-09-15 22:34 ` Luca Ceresoli
2015-10-01 9:36 ` Luca Ceresoli
2015-10-01 10:03 ` Peter Korsgaard
2015-09-15 22:31 ` Luca Ceresoli
2015-09-16 7:32 ` Peter Korsgaard
2015-09-18 15:47 ` Luca Ceresoli
2015-09-09 9:34 ` Arnout Vandecappelle
2015-09-09 11:23 ` Thomas Petazzoni
2015-09-09 11:29 ` Thomas Petazzoni
2015-09-09 20:33 ` Arnout Vandecappelle
2015-09-14 16:07 ` Luca Ceresoli
2015-09-14 16:05 ` Luca Ceresoli
2015-09-14 19:34 ` Thomas Petazzoni
2015-09-14 20:19 ` Arnout Vandecappelle
2015-09-15 22:07 ` Luca Ceresoli
2015-09-08 21:28 ` [Buildroot] [RFC 4/6] system: strip the initial /dev for mdev-only /dev management Luca Ceresoli
2015-09-08 21:28 ` [Buildroot] [RFC 5/6] docs/manual: document "Dynamic using mdev only" " Luca Ceresoli
2015-09-09 10:39 ` Arnout Vandecappelle
2015-09-08 21:28 ` [Buildroot] [RFC 6/6] **** DO NOT COMMIT THIS **** ugly stuff to test mdev-only " Luca Ceresoli
2015-09-09 9:26 ` [Buildroot] [RFC 0/6] mdev-only /dev management (without devtmpfs) Arnout Vandecappelle
2015-09-09 11:30 ` Thomas Petazzoni
2015-09-14 21:03 ` Peter Korsgaard
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=55F02630.5050500@lucaceresoli.net \
--to=luca@lucaceresoli.net \
--cc=buildroot@busybox.net \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.