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wdenkb8fb6192004-08-02 21:11:11 +00001
2In U-Boot, we implemented the networked console via the standard
3"devices" mechanism, which means that you can switch between the
4serial and network input/output devices by adjusting the 'stdin' and
5'stdout' environment variables. To switch to the networked console,
6set either of these variables to "nc". Input and output can be
7switched independently.
8
wdenka0ebde52004-09-08 22:03:11 +00009We use an environment variable 'ncip' to set the IP address and the
10port of the destination. The format is <ip_addr>:<port>. If <port> is
11omitted, the value of 6666 is used. If the env var doesn't exist, the
12broadcast address and port 6666 are used. If it is set to an IP
13address of 0 (or 0.0.0.0) then no messages are sent to the network.
14
wdenkb8fb6192004-08-02 21:11:11 +000015On the host side, please use this script to access the console:
16
17+++++++++++++++++++++++++++++++++++++++++++
18#! /bin/bash
19
20TARGET_IP=$1
21
22stty -icanon -echo intr ^T
23nc -u -l -p 6666 < /dev/null &
24nc -u ${TARGET_IP} 6666
25stty icanon echo intr ^C
wdenka0ebde52004-09-08 22:03:11 +000026+++++++++++++++++++++++++++++++++++++++++++
27
wdenkb3a4a702004-12-10 11:40:40 +000028It turns out that 'netcat' cannot be used to listen to broadcast
wdenka0ebde52004-09-08 22:03:11 +000029packets. We developed our own tool 'ncb' (see tools directory) that
30listens to broadcast packets on a given port and dumps them to the
31standard output. use it as follows:
32
33+++++++++++++++++++++++++++++++++++++++++++
34#! /bin/bash
35
36stty icanon echo intr ^T
37./ncb &
38nc -u mpc5200 6666
39stty icanon echo intr ^C
40kill 0
wdenkb8fb6192004-08-02 21:11:11 +000041+++++++++++++++++++++++++++++++++++++++++++
42
43For Linux, the network-based console needs special configuration.
44Minimally, the host IP address needs to be specified. This can be
45done either via the kernel command line, or by passing parameters
46while loading the netconsole.o module (when used in a loadable module
47configuration). Please refer to Documentation/networking/logging.txt
48file for the original Ingo Molnar's documentation on how to pass
49parameters to the loadable module.
50
51The format of the kernel command line parameter (for the static
52configuration) is as follows:
53
54 netconsole=[src-port]@[src-ip]/[<dev>],[tgt-port]@<tgt-ip>/[tgt-macaddr]
55
56where
57
58 src-port source for UDP packets
59 (defaults to 6665)
60 src-ip source IP to use
61 (defaults to the interface's address)
62 dev network interface
63 (defaults to eth0)
64 tgt-port port for logging agent
65 (defaults to 6666)
66 tgt-ip IP address for logging agent
67 (this is the required parameter)
68 tgt-macaddr ethernet MAC address for logging agent
69 (defaults to broadcast)
70
71Examples:
72
73 netconsole=4444@10.0.0.1/eth1,9353@10.0.0.2/12:34:56:78:9a:bc
74
75or
76
77 netconsole=@/,@192.168.3.1/
78
79Please note that for the Linux networked console to work, the
80ethernet interface has to be up by the time the netconsole driver is
81initialized. This means that in case of static kernel configuration,
82the respective Ethernet interface has to be brought up using the "IP
83Autoconfiguration" kernel feature, which is usually done by defaults
84in the ELDK-NFS-based environment.
85
86To browse the Linux network console output, use the 'netcat' tool invoked
87as follows:
88
89 nc -u -l -p 6666
wdenkb3a4a702004-12-10 11:40:40 +000090
91Note that unlike the U-Boot implementation the Linux netconsole is
92unidirectional, i. e. you have console output only in Linux.