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68ceb29e WD |
1 | |
2 | In U-Boot, we implemented the networked console via the standard | |
3 | "devices" mechanism, which means that you can switch between the | |
4 | serial and network input/output devices by adjusting the 'stdin' and | |
5 | 'stdout' environment variables. To switch to the networked console, | |
6 | set either of these variables to "nc". Input and output can be | |
7 | switched independently. | |
8 | ||
eedcd078 WD |
9 | We use an environment variable 'ncip' to set the IP address and the |
10 | port of the destination. The format is <ip_addr>:<port>. If <port> is | |
11 | omitted, the value of 6666 is used. If the env var doesn't exist, the | |
12 | broadcast address and port 6666 are used. If it is set to an IP | |
13 | address of 0 (or 0.0.0.0) then no messages are sent to the network. | |
14 | ||
b1bf6f2c WD |
15 | For example, if your server IP is 192.168.1.1, you could use: |
16 | ||
17 | => setenv nc 'setenv stdout nc;setenv stdin nc' | |
18 | => setenv ncip 192.168.1.1 | |
19 | => saveenv | |
20 | => run nc | |
21 | ||
22 | ||
68ceb29e WD |
23 | On the host side, please use this script to access the console: |
24 | ||
25 | +++++++++++++++++++++++++++++++++++++++++++ | |
26 | #! /bin/bash | |
27 | ||
b1bf6f2c | 28 | [ $# = 1 ] || { echo "Usage: $0 target_ip" >&2 ; exit 1 ; } |
68ceb29e WD |
29 | TARGET_IP=$1 |
30 | ||
31 | stty -icanon -echo intr ^T | |
32 | nc -u -l -p 6666 < /dev/null & | |
33 | nc -u ${TARGET_IP} 6666 | |
34 | stty icanon echo intr ^C | |
35 | +++++++++++++++++++++++++++++++++++++++++++ | |
36 | ||
b1bf6f2c WD |
37 | The script expects exactly one argument, which is interpreted as the |
38 | target IP address (or host name, assuming DNS is working). The script | |
39 | can be interrupted by pressing ^T (CTRL-T). | |
40 | ||
25d6712a | 41 | It turns out that 'netcat' cannot be used to listen to broadcast |
eedcd078 WD |
42 | packets. We developed our own tool 'ncb' (see tools directory) that |
43 | listens to broadcast packets on a given port and dumps them to the | |
44 | standard output. use it as follows: | |
45 | ||
46 | +++++++++++++++++++++++++++++++++++++++++++ | |
47 | #! /bin/bash | |
48 | ||
b1bf6f2c WD |
49 | [ $# = 1 ] || { echo "Usage: $0 target_ip" >&2 ; exit 1 ; } |
50 | TARGET_IP=$1 | |
51 | ||
eedcd078 WD |
52 | stty icanon echo intr ^T |
53 | ./ncb & | |
b1bf6f2c | 54 | nc -u ${TARGET_IP} 6666 |
eedcd078 WD |
55 | stty icanon echo intr ^C |
56 | kill 0 | |
57 | +++++++++++++++++++++++++++++++++++++++++++ | |
58 | ||
b1bf6f2c WD |
59 | Again, this script takes exactly one argument, which is interpreted |
60 | as the target IP address (or host name, assuming DNS is working). The | |
61 | script can be interrupted by pressing ^T (CTRL-T). | |
62 | ||
63 | The 'ncb' tool can be found in the tools directory; it will not be | |
64 | built by default so you will ither have to adjust the Makefile or | |
65 | build it manually. | |
66 | ||
67 | ||
68ceb29e WD |
68 | For Linux, the network-based console needs special configuration. |
69 | Minimally, the host IP address needs to be specified. This can be | |
70 | done either via the kernel command line, or by passing parameters | |
71 | while loading the netconsole.o module (when used in a loadable module | |
72 | configuration). Please refer to Documentation/networking/logging.txt | |
73 | file for the original Ingo Molnar's documentation on how to pass | |
74 | parameters to the loadable module. | |
75 | ||
76 | The format of the kernel command line parameter (for the static | |
77 | configuration) is as follows: | |
78 | ||
79 | netconsole=[src-port]@[src-ip]/[<dev>],[tgt-port]@<tgt-ip>/[tgt-macaddr] | |
80 | ||
81 | where | |
82 | ||
83 | src-port source for UDP packets | |
84 | (defaults to 6665) | |
85 | src-ip source IP to use | |
86 | (defaults to the interface's address) | |
87 | dev network interface | |
88 | (defaults to eth0) | |
89 | tgt-port port for logging agent | |
90 | (defaults to 6666) | |
91 | tgt-ip IP address for logging agent | |
92 | (this is the required parameter) | |
93 | tgt-macaddr ethernet MAC address for logging agent | |
94 | (defaults to broadcast) | |
95 | ||
96 | Examples: | |
97 | ||
98 | netconsole=4444@10.0.0.1/eth1,9353@10.0.0.2/12:34:56:78:9a:bc | |
99 | ||
100 | or | |
101 | ||
102 | netconsole=@/,@192.168.3.1/ | |
103 | ||
104 | Please note that for the Linux networked console to work, the | |
105 | ethernet interface has to be up by the time the netconsole driver is | |
106 | initialized. This means that in case of static kernel configuration, | |
107 | the respective Ethernet interface has to be brought up using the "IP | |
108 | Autoconfiguration" kernel feature, which is usually done by defaults | |
109 | in the ELDK-NFS-based environment. | |
110 | ||
111 | To browse the Linux network console output, use the 'netcat' tool invoked | |
112 | as follows: | |
113 | ||
114 | nc -u -l -p 6666 | |
25d6712a WD |
115 | |
116 | Note that unlike the U-Boot implementation the Linux netconsole is | |
117 | unidirectional, i. e. you have console output only in Linux. |