DIVISION OF ENGINEERING AND APPLIED SCIENCES
HARVARD UNIVERSITY

CS 161. Operating Systems Matt Welsh Spring 2005 Using screen(1) for Debugging By Philip Zeyliger (This is a new document; e-mail corrections.) [CS161 Home Page]

You're going to be spending a lot of time in front of GDB this semester. It's worthwhile to invest some time now into your environment. I found it frustrating to setup the two windows needed for connecting gdb to a kernel, so I used screen(1) to split one (bigger) terminal into two, thereby enabling me to interact with kernel and gdb in one window, like so:

1. Put the following (adjust directories as necessary) into ~/.screenrc.161:

   bindkey -k k1 screen 1
   bindkey -k k2 screen 2
   bind q quit
   bind j focus down
   bind k focus up
   startup_message off
   deflogin off
   
   screen -t "sys161" 1
   stuff "pushd ~/cs161/root^M"
   stuff "sys161 -w kernel^M"
   split
   focus down
   screen -t "GDB" 2 
   stuff "pushd ~/cs161/root^M"
   stuff "cs161-gdb kernel^M"
   sleep 1
   stuff "db161^M"
   

2. Put the following into ~/.gdbinit (replace U/S/USERNAME):

   cd /nfs/home/U/S/USERNAME/cs161/src/kern/compile/ASST5
   define db161
   target remote unix:/nfs/home/U/S/USERNAME/cs161/root/.sockets/gdb
   b panic
   end
   

3. Make an alias. For example, I did: "alias debug screen -c /home/U/S/USERNAME/.screenrc.161", and put that in my .tcshrc.
4. Now you can type "debug" and get a cool split-screen debug window.