Show pagesourceOld revisionsBacklinksBack to top × Table of Contents Hotplug -- Legacy Configuration Examples Coldplug Logs generated by Coldplug script below Troubleshoot Notes Hotplug -- Legacy Historic information! This page contains archived information that is only kept for research purposes. The contents are most likely outdated. See the Hotplug article for information on the current approach. The “hotplug2” daemon was removed in 2013 (r36987) and replaced with procd. Hotplug2 was a trivial replacement of some of the UDev functionality in a tiny pack, intended for Linux early userspace: Init RAM FS and InitRD. Hotplug executes scripts located in the respective hotplug directory: /etc/hotplug.d/ on certain events, like when an interface goes up or down or when a button gets pressed. It can be very useful with PPPoE-connection or in an unstable network. Hotplug has been available since OpenWrt 'Kamikaze' 7.06 and was removed in 2013, prior to the release of “Attitude Adjustment”. https://dev.openwrt.org/browser/trunk/package/hotplug2?rev=36446 Example: See r37336: procd: make old button hotplug rules work until all packages are migrated It is also used by hardware.button What is hotplug? Best answer to this question is found on Chris Lumens's website. How it works Every time an interface goes up or down, all scripts in the /etc/hotplug.d/iface/ directory are executed, in alphabetical order. According to an informal convention a numeric prefix is added to each script name to set the correct order of running. That's why the scripts there are named like this: /etc/hotplug.d/iface/<nn>-<scriptname> e.g.: 10-routes, 20-firewall Kernel module: button-hotplug Configuration Modify /etc/hotplug2.rules to enable Hotplug execute your script(s) in /etc/hotplug.d/<type>. <type> is a kind of hotplug device; such as usb. In /etc/hotplug2.rules, remove '^' before <type> which can be net, input, button, usb etc. $include /etc/hotplug2-common.rules SUBSYSTEM ~~ (^net$|^input$|^button$|^usb$|^ieee1394$|^block$|^atm$|^zaptel$|^tty$) { exec /sbin/hotplug-call %SUBSYSTEM% } DEVICENAME == watchdog { exec /sbin/watchdog -t 5 /dev/watchdog next-event } Simply place your script(s) into the respective hotplug subdirectory. Script looks like this: There are three main environment variables that are passed to each iface hotplug-script: Variable name Description ACTION Either “ifup” or “ifdown” INTERFACE Name of the interface which went up or down (e.g. “wan” or “ppp0”) DEVICE Physical device name which interface went up or down (e.g. “eth0.1” or “br-lan”) Examples Save the example script at /etc/hotplug.d/iface/99-my-action. #!/bin/sh [ “$ACTION” = ifup ] && { logger -t button-hotplug Device: $DEVICE / Action: $ACTION } Every time an interface goes up then the if/fi statement will be executed. → hardware.button makes ample use of hotplug. Niii has posted this quick example for a USB WiFi device hotplug event to trigger an init.d network restart wlan0 script. For determine RTL8188SU_PRODID variable, use “lsusb -v”: idVendor 0x0bda Realtek Semiconductor Corp. idProduct 0x8171 RTL8188SU 802.11n WLAN Adapter bcdDevice 2.00 /etc/hotplug.d/usb/20-rtl8188su #!/bin/sh BINARY=“/sbin/wifi up” RTL8188SU_PRODID=“bda/8171/200” if [ “${PRODUCT}” = “${RTL8188SU_PRODID}” ]; then if [ “${ACTION}” = “add” ]; then ${BINARY} fi fi /etc/hotplug.d/usb/20-cp210x An other script to create a symlink instead of renaming the device. I test if DEVICE_NAME is empty because when I plug usb device I retrieve two add event, and the first come before created device, so symlink fails. #!/bin/sh CP210_PRODID=“10c4/ea60/100” SYMLINK=“my_link” if [ “${PRODUCT}” = “${CP210_PRODID}” ]; then if [ “${ACTION}” = “add” ]; then DEVICE_NAME=$(ls /sys/$DEVPATH | grep tty) if [ -z ${DEVICE_NAME} ]; then logger -t Hotplug Warning DEVICE_NAME is empty exit fi logger -t Hotplug Device name of cp210 is $DEVICE_NAME ln -s /dev/$DEVICE_NAME /dev/${SYMLINK} logger -t Hotplug Symlink from /dev/$DEVICE_NAME to /dev/${SYMLINK} created fi fi if [ “${PRODUCT}” = “${CP210_PRODID}” ]; then if [ “${ACTION}” = “remove” ]; then rm /dev/${SYMLINK} logger -t Hotplug Symlink /dev/${SYMLINK} removed fi fi Script that detects if plugged usb device is bluetooth or not. #!/bin/sh BT_PRODID=“a12/1/” BT_PRODID_HOT=`echo $PRODUCT | cut -c 1-6` #logger -t HOTPLUG “PRODUCT ID is” $BT_PRODID_HOT if [ “$BT_PRODID_HOT” = “$BT_PRODID” ]; then if [ “$ACTION” = “add” ]; then logger -t HOTPLUG “bluetooth device has been plugged in!” if [ “$BSBTID_NEW” = “$BSBTID_OLD” ]; then logger -t HOTPLUG “bluetooth device hasn't changed” else logger -t HOTPLUG “bluetooth device has changed” fi fi if [ “$ACTION” = “remove” ]; then logger -t HOTPLUG “bluetooth device has been removed!” fi else logger -t HOTPLUG “USB device is not bluetooth” fi Auto start mjpg-streamer when an usb camera is plugged in. Firstly, remove '^' before 'input' in /etc/hotplug2.rules to enable Hotplug execute script(s) in /etc/hotplug.d/input. Secondly, add /etc/hotplug.d/input/30-mjpg-streamer case "$ACTION" in add) # start process /etc/init.d/mjpg-streamer start ;; remove) # stop process /etc/init.d/mjpg-streamer stop ;; esac Coldplug If you had notice the udev and eudev were removed in the openwrt 18.0.* release, don't be afraid because you still can make the things works. Using hotplug scripts as coldplug You just need to pay atention at the ACTION env var, at the boot are executed 'bind' actions. So, just add this option to hotplug run accordinly. In my case I used this: Take a look into file /etc/hotplug.d/usb/22-symlinks #!/bin/sh # Description: Action executed on boot (bind) and with the system on the fly if [ "$ACTION" = 'bind' ] ; then case "${PRODUCT}" in 1bc7*) # Telit HE910 3g modules product id prefix DEVICE_NAME=$(ls /sys/$DEVPATH | grep tty) DEVICE_TTY=$(ls /sys/$DEVPATH/tty/) # Module Telit HE910-* connected to minipciexpress slot MAIN if [ ${DEVICENAME} = '1-1.3:1.0' ] ; then ln -s /dev/$DEVICE_TTY /dev/ttyMODULO1_DIAL logger -t Hotplug Symlink from /dev/$DEVICE_TTY to /dev/ttyMODULO1_DIAL created elif [ ${DEVICENAME} = '1-1.3:1.6' ] ; then ln -s /dev/$DEVICE_TTY /dev/ttyMODULO1_DATA logger -t Hotplug Symlink from /dev/$DEVICE_TTY to /dev/ttyMODULO1_DATA created # Module Telit HE910-* connected to minipciexpress slot SECONDARY elif [ ${DEVICENAME} = '1-1.2:1.0' ] ; then ln -s /dev/$DEVICE_TTY /dev/ttyMODULO2_DIAL logger -t Hotplug Symlink from /dev/$DEVICE_TTY to /dev/ttyMODULO2_DIAL created elif [ ${DEVICENAME} = '1-1.2:1.6' ] ; then ln -s /dev/$DEVICE_TTY /dev/ttyMODULO2_DATA logger -t Hotplug Symlink from /dev/$DEVICE_TTY to /dev/ttyMODULO2_DATA created fi ;; esac fi # Action to remove the symlinks if [ "$ACTION" = 'remove' ] ; then case "${PRODUCT}" in 1bc7*) # Telit HE910 3g modules product id prefix # Module Telit HE910-* connected to minipciexpress slot MAIN if [ ${DEVICENAME} = '1-1.3:1.0' ] ; then rm /dev/ttyMODULO1_DIAL logger -t Hotplug Symlink /dev/ttyMODULO1_DIAL removed elif [ ${DEVICENAME} = '1-1.3:1.6' ] ; then rm /dev/ttyMODULO1_DATA logger -t Hotplug Symlink /dev/ttyMODULO1_DATA removed # Module Telit HE910-* connected to minipciexpress slot SECONDARY elif [ ${DEVICENAME} = '1-1.2:1.0' ] ; then rm /dev/ttyMODULO2_DIAL logger -t Hotplug Symlink /dev/ttyMODULO2_DIAL removed elif [ ${DEVICENAME} = '1-1.2:1.6' ] ; then rm /dev/ttyMODULO2_DATA logger -t Hotplug Symlink /dev/ttyMODULO2_DATA removed fi ;; esac fi Logs generated by Coldplug script below root@OpenWrt:~#logread | grep Hotplug Fri Sep 21 15:31:00 2018 user.notice Hotplug: Symlink from /dev/ttyACM0 to /dev/ttyMODULO2_DIAL created Fri Sep 21 15:31:06 2018 user.notice Hotplug: Symlink from /dev/ttyACM3 to /dev/ttyMODULO2_DATA created Fri Sep 21 15:31:39 2018 user.notice Hotplug: Symlink from /dev/ttyACM6 to /dev/ttyMODULO1_DIAL created Fri Sep 21 15:31:46 2018 user.notice Hotplug: Symlink from /dev/ttyACM9 to /dev/ttyMODULO1_DATA created Fri Sep 21 15:32:03 2018 user.notice Hotplug: Symlink /dev/ttyMODULO1_DIAL removed Fri Sep 21 15:32:10 2018 user.notice Hotplug: Symlink /dev/ttyMODULO1_DATA removed Fri Sep 21 15:33:17 2018 user.notice Hotplug: Symlink /dev/ttyMODULO2_DIAL removed Fri Sep 21 15:33:24 2018 user.notice Hotplug: Symlink /dev/ttyMODULO2_DATA removed root@OpenWrt:~# Troubleshoot If you wish to troubleshoot hotplug of some type of device this can be done via simple debug script. For example to troubleshoot adding and removing of any type of usb devices, simply create this /etc/hotplug.d/usb/10-usb_debug script with all variables: #!/bin/sh logger -t DEBUG "hotplug usb: action='$ACTION' devicename='$DEVICENAME' devname='$DEVNAME' devpath='$DEVPATH' product='$PRODUCT' type='$TYPE' interface='$INTERFACE'" or this one with only essential ones used: #!/bin/sh logger -t DEBUG "hotplug usb: action='$ACTION' product='$PRODUCT' type='$TYPE' interface='$INTERFACE'" So with debuging enabled here is how it looks like when you plug two different usb bluetooth dongles: action='add' product='a12/1/1915' type='224/1/1' interface='' action='add' product='a12/1/1915' type='224/1/1' interface='224/1/1' action='add' product='a12/1/1915' type='224/1/1' interface='224/1/1' action='add' product='a12/1/1915' type='224/1/1' interface='254/1/0' action='remove' product='a12/1/1915' type='224/1/1' interface='224/1/1' action='remove' product='a12/1/1915' type='224/1/1' interface='224/1/1' action='remove' product='a12/1/1915' type='224/1/1' interface='254/1/0' action='remove' product='a12/1/1915' type='224/1/1' interface='' action='add' product='a12/1/134' type='224/1/1' interface='' action='add' product='a12/1/134' type='224/1/1' interface='224/1/1' action='add' product='a12/1/134' type='224/1/1' interface='224/1/1' So my using some (maybe flawed) logic we can deduce that match bluetooth is possible if we use product='a12/1*' Notes This website uses cookies. By using the website, you agree with storing cookies on your computer. Also you acknowledge that you have read and understand our Privacy Policy. If you do not agree leave the website.OKMore information about cookies Last modified: 2019/09/09 21:08by vgaetera