Hot code loading
From Openmoko
To change a running system
Start erlang as a node on your host
This is my /etc/X11/Xsession.d/80zhone. As you can see the erlang node's got a name "-name neo@192.168.0.202" (a running erlang virtual machine is called an erlang node). And it's got a cookie "-setcookie SFEWRG34AFDSGAFG35235". This is all that's needed on the neo.
#!/bin/sh -e #zhone > /tmp/zhone.log 2>&1 & /home/root/cean/start.sh -setcookie SFEWRG34AFDSGAFG35235 -name neo@192.168.0.202 -noshell -pa /home/root/trunk -s main start > debug.txt renice -3 $! exit 0
Every erlang node in your network should have a unique name, and a common cookie. Start an erlang node on your host PC with a unique name and the common cookie:
erl -setcookie SFEWRG34AFDSGAFG35235 -name 'host@192.168.0.200'
From your host erlang console try
net_adm:ping('neo@192.168.0.202').
The response should be 'pong' if you have a successful connection - if not, the response is 'pang'
Then try the shell command
nodes().
The response should be a list of all known nodes in your network.
HotLoad the code
To carry out Hot Code Loading type on your host erlang shell:
net_adm:ping('neo@192.168.0.202').
nl(your_modulename).
Substitute your_modulename with the name of the module you want to load into the virtual machine on your neo. The response should be 'abcast' if sucessful. If not the response is 'error'.
The ping command is only necessary the first time to let your host node find your neo node. Don't forget to copy the compiled erlang file to your neo, hot code loading does not copy your beam file to the file system.
