udev/start_udev

   1 #!/bin/sh
   2
   3 # - if /dev is not mounted - mount as a devtmpfs (CONFIG_DEVTMPFS=y) or tmpfs
   4 # - if /dev is mounted (e.g. due to handover from initramfs or
   5 #   CONFIG_DEVTMPFS_MOUNT=y), remount with specific options
   6 # - some video drivers require exec access in /dev, thus it's set here
   7 # - for completness, we add few sanity limits (2k non-empty files, 16k inodes)
   8
   9 UDEVOPTS="exec,nosuid,noatime,mode=0755,nr_blocks=2048,nr_inodes=16384"
  10 if /bin/mountpoint -q /dev ; then
  11         /bin/mount -n -o remount,${UDEVOPTS} dev /dev
  12 else
  13         if /bin/sed -n '/devtmpfs/q1' /proc/filesystems ; then
  14                 UDEVFS=tmpfs
  15         else
  16                 UDEVFS=devtmpfs
  17         fi
  18         /bin/mount -n -t $UDEVFS -o ${UDEVOPTS} dev /dev
  19 fi
  20
  21 # make sure hotplugger is not set
  22 echo > /proc/sys/kernel/hotplug
  23
  24 # since v155, udevd automatically copies /lib/udev/devices
  25 # and creates /proc/{kcore,self/fd/{0,1,2}} symlinks
  26
  27 # launch udev daemon, make sure it's not running first
  28 test -z "$(/bin/pidof -s udevd)" && /sbin/udevd --daemon
  29
  30 # coldplug devices and wait for the queue to be processed
  31 /sbin/udevadm trigger --type=subsystems --action=add
  32 /sbin/udevadm trigger --type=devices --action=add
  33 /sbin/udevadm settle
  34
  35 # retry any failures
  36 /sbin/udevadm trigger --type=failed --action=add
  37 /sbin/udevadm settle