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author | H. Nikolaus Schaller <hns@goldelico.com> | 2012-03-26 20:55:28 +0200 |
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committer | H. Nikolaus Schaller <hns@goldelico.com> | 2012-03-26 20:55:28 +0200 |
commit | 92988a21ad4c4c9504295ccb580c9f806134471b (patch) | |
tree | 5effc9f14170112450de05c67dafbe8d5034d595 /u-boot/doc/README.NetConsole | |
parent | ca2b506783b676c95762c54ea24dcfdaae1947c9 (diff) | |
download | bootable_bootloader_goldelico_gta04-92988a21ad4c4c9504295ccb580c9f806134471b.zip bootable_bootloader_goldelico_gta04-92988a21ad4c4c9504295ccb580c9f806134471b.tar.gz bootable_bootloader_goldelico_gta04-92988a21ad4c4c9504295ccb580c9f806134471b.tar.bz2 |
added boot script files to repository
Diffstat (limited to 'u-boot/doc/README.NetConsole')
-rw-r--r-- | u-boot/doc/README.NetConsole | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/u-boot/doc/README.NetConsole b/u-boot/doc/README.NetConsole new file mode 100644 index 0000000..c8bcb90 --- /dev/null +++ b/u-boot/doc/README.NetConsole @@ -0,0 +1,92 @@ + +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. + +For example, if your server IP is 192.168.1.1, you could use: + + => setenv nc 'setenv stdout nc;setenv stdin nc' + => setenv ncip 192.168.1.1 + => saveenv + => run nc + + +On the host side, please use this script to access the console: + + tools/netconsole <ip> [port] + +The script uses netcat to talk to the board over UDP. It requires you to +specify the target IP address (or host name, assuming DNS is working). The +script can be interrupted by pressing ^T (CTRL-T). + +Be aware that in some distributives (Fedora Core 5 at least) +usage of nc has been changed and -l and -p options are considered +as mutually exclusive. If nc complains about options provided, +you can just remove the -p option from the script. + +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. It will be built when compiling for a board which +has CONFIG_NETCONSOLE defined. If the netconsole script can find it +in PATH or in the same directory, it will be used instead. + +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. |