mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-11-17 02:08:38 +00:00
92 lines
3 KiB
Text
92 lines
3 KiB
Text
|
|
In U-Boot, we implemented the networked console via the standard
|
|
"devices" mechanism, which means that you can switch between the
|
|
serial and network input/output devices by adjusting the 'stdin' and
|
|
'stdout' environment variables. To switch to the networked console,
|
|
set either of these variables to "nc". Input and output can be
|
|
switched independently.
|
|
|
|
We use an environment variable 'ncip' to set the IP address and the
|
|
port of the destination. The format is <ip_addr>:<port>. If <port> is
|
|
omitted, the value of 6666 is used. If the env var doesn't exist, the
|
|
broadcast address and port 6666 are used. If it is set to an IP
|
|
address of 0 (or 0.0.0.0) then no messages are sent to the network.
|
|
|
|
On the host side, please use this script to access the console:
|
|
|
|
+++++++++++++++++++++++++++++++++++++++++++
|
|
#! /bin/bash
|
|
|
|
TARGET_IP=$1
|
|
|
|
stty -icanon -echo intr ^T
|
|
nc -u -l -p 6666 < /dev/null &
|
|
nc -u ${TARGET_IP} 6666
|
|
stty icanon echo intr ^C
|
|
+++++++++++++++++++++++++++++++++++++++++++
|
|
|
|
It turns out that 'netcat' cannot be used to listen to broadcast
|
|
packets. We developed our own tool 'ncb' (see tools directory) that
|
|
listens to broadcast packets on a given port and dumps them to the
|
|
standard output. use it as follows:
|
|
|
|
+++++++++++++++++++++++++++++++++++++++++++
|
|
#! /bin/bash
|
|
|
|
stty icanon echo intr ^T
|
|
./ncb &
|
|
nc -u mpc5200 6666
|
|
stty icanon echo intr ^C
|
|
kill 0
|
|
+++++++++++++++++++++++++++++++++++++++++++
|
|
|
|
For Linux, the network-based console needs special configuration.
|
|
Minimally, the host IP address needs to be specified. This can be
|
|
done either via the kernel command line, or by passing parameters
|
|
while loading the netconsole.o module (when used in a loadable module
|
|
configuration). Please refer to Documentation/networking/logging.txt
|
|
file for the original Ingo Molnar's documentation on how to pass
|
|
parameters to the loadable module.
|
|
|
|
The format of the kernel command line parameter (for the static
|
|
configuration) is as follows:
|
|
|
|
netconsole=[src-port]@[src-ip]/[<dev>],[tgt-port]@<tgt-ip>/[tgt-macaddr]
|
|
|
|
where
|
|
|
|
src-port source for UDP packets
|
|
(defaults to 6665)
|
|
src-ip source IP to use
|
|
(defaults to the interface's address)
|
|
dev network interface
|
|
(defaults to eth0)
|
|
tgt-port port for logging agent
|
|
(defaults to 6666)
|
|
tgt-ip IP address for logging agent
|
|
(this is the required parameter)
|
|
tgt-macaddr ethernet MAC address for logging agent
|
|
(defaults to broadcast)
|
|
|
|
Examples:
|
|
|
|
netconsole=4444@10.0.0.1/eth1,9353@10.0.0.2/12:34:56:78:9a:bc
|
|
|
|
or
|
|
|
|
netconsole=@/,@192.168.3.1/
|
|
|
|
Please note that for the Linux networked console to work, the
|
|
ethernet interface has to be up by the time the netconsole driver is
|
|
initialized. This means that in case of static kernel configuration,
|
|
the respective Ethernet interface has to be brought up using the "IP
|
|
Autoconfiguration" kernel feature, which is usually done by defaults
|
|
in the ELDK-NFS-based environment.
|
|
|
|
To browse the Linux network console output, use the 'netcat' tool invoked
|
|
as follows:
|
|
|
|
nc -u -l -p 6666
|
|
|
|
Note that unlike the U-Boot implementation the Linux netconsole is
|
|
unidirectional, i. e. you have console output only in Linux.
|