DebWrt Netconsole

DebWrt by default includes netconsole for devices with no normal serial interface. With netconsole it is possible to have all kernel boot messages ( not the messages from init and initscripts! ) forwarded over the network to a remote computer. eth0 is used as interface to forward messages from. Note that eth0 may vary from device to device.

Settings

Configuration is done by kernel boot parameter with

netconsole=6665@192.168.1.1/eth0,6666@192.168.1.2/

That means

• Embedded device: 6665@192.168.1.1/eth0
  • device eth0
  • address 192.168.1.1
  • port 6665
• Remote computer: 6666@192.168.1.2
  • address 192.168.1.2
  • port 6666

The kernel boot parameter netconsole is defined during make menuconfig as part of CONFIG_CMDLINE.

Remote computer setup

• configure the LAN port on the remote computer connected to the eth0 on the device with:
  • ip: 192,.168.1.2
  • netmask: 255.255.255.0
  • no default gw
• use netcat to listen for UDP packets on port 6666 and dump contents to the console

  nc -l -p 6666 -u
  

Links

• ​Netconsole kernel documentation