Run udev at start of boot

Run udev at start of boot

[Midhun A]

Hi All,

   I have compiled udev 116 for my ARM system and put in the required
scripts in /etc/init.d/rcS script. As this script is executed at the
end boot, my devices get created at the end of boot. I would like to
have the devices be created at the start of boot - as it happens in
most Linux systems. How do I do that?


My rcS script is as follows:

#!/bin/ash

#Start the network interface
/sbin/ifconfig eth0 xxx.xxx.xxx.xxx

#mounting proc
mount -t proc proc /proc

#mounting sysfs
mount -t sysfs  sysfs /sys

#copy initial entries for /dev
cp -a /lib/udev/devices/* /dev/

#disable hotplug
echo > /proc/sys/kernel/hotplug

mkdir -p /dev/.udev/db

#start udev
udevd --daemon

udevtrigger

#wait until udev events are handled
udevsettle


Thanks,
Midhun.

-------------------------------------------------------------------------
This SF.net email is sponsored by: Splunk Inc.
Still grepping through log files to find problems?  Stop.
Now Search log events and configuration files using AJAX and a browser.
Download your FREE copy of Splunk now >> http://get.splunk.com/
_______________________________________________
Linux-hotplug-devel mailing list  http://linux-hotplug.sourceforge.net
Linux-hotplug-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-hotplug-devel

Re: Run udev at start of boot

[Phillip Susi]

Midhun A wrote:
> Hi All,
> 
>    I have compiled udev 116 for my ARM system and put in the required
> scripts in /etc/init.d/rcS script. As this script is executed at the
> end boot, my devices get created at the end of boot. I would like to
> have the devices be created at the start of boot - as it happens in
> most Linux systems. How do I do that?

Depends on how your system is booting.  IIRC, Ubuntu uses an initramfs 
to boot up, then chains into the real root.  Udev is started early on in 
the initramfs init script so it can enumerate the hardware, then is 
killed off just before the chroot to the real root and then init starts 
up the copy in the real root.


-------------------------------------------------------------------------
This SF.net email is sponsored by: Splunk Inc.
Still grepping through log files to find problems?  Stop.
Now Search log events and configuration files using AJAX and a browser.
Download your FREE copy of Splunk now >> http://get.splunk.com/
_______________________________________________
Linux-hotplug-devel mailing list  http://linux-hotplug.sourceforge.net
Linux-hotplug-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-hotplug-devel

Re: Run udev at start of boot

[Midhun A]

Hi,


> Depends on how your system is booting.  IIRC, Ubuntu uses an initramfs
> to boot up, then chains into the real root.  Udev is started early on in
> the initramfs init script so it can enumerate the hardware, then is
> killed off just before the chroot to the real root and then init starts
> up the copy in the real root.

   As of now, I am using only a Ramdisk to boot as my board has only
8MB of flash. Any idea as to how I can start udev in this situation?
Can it be compiled into the kernel so that it starts before the kernel
starts loading the drivers?

Thanks,
Midhun.

-------------------------------------------------------------------------
This SF.net email is sponsored by: Splunk Inc.
Still grepping through log files to find problems?  Stop.
Now Search log events and configuration files using AJAX and a browser.
Download your FREE copy of Splunk now >> http://get.splunk.com/
_______________________________________________
Linux-hotplug-devel mailing list  http://linux-hotplug.sourceforge.net
Linux-hotplug-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-hotplug-devel

Re: Run udev at start of boot

[Greg KH]

On Thu, Nov 01, 2007 at 10:55:10PM +0530, Midhun A wrote:
> Hi,
> 
> 
> > Depends on how your system is booting.  IIRC, Ubuntu uses an initramfs
> > to boot up, then chains into the real root.  Udev is started early on in
> > the initramfs init script so it can enumerate the hardware, then is
> > killed off just before the chroot to the real root and then init starts
> > up the copy in the real root.
> 
>    As of now, I am using only a Ramdisk to boot as my board has only
> 8MB of flash. Any idea as to how I can start udev in this situation?
> Can it be compiled into the kernel so that it starts before the kernel
> starts loading the drivers?

udev is a userspace program, not something that can be "built into the
kernel".

udev is the thing that does the loding of the kernel drivers, so of
course it runs first :)

thanks,

greg k-h

-------------------------------------------------------------------------
This SF.net email is sponsored by: Splunk Inc.
Still grepping through log files to find problems?  Stop.
Now Search log events and configuration files using AJAX and a browser.
Download your FREE copy of Splunk now >> http://get.splunk.com/
_______________________________________________
Linux-hotplug-devel mailing list  http://linux-hotplug.sourceforge.net
Linux-hotplug-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-hotplug-devel