Debugging K42/Mambo

1. Log into K42

   ssh leon@mambo1

2. Define environment variables accordingly
   • TRACEPROC=<process>
     Print the syscalls (with arguments and return values) that <process> invokes to Mambo console
   • DEBUGPROC=<process>
     Break <process> immediately after exec()

     leon@mambo1> export DEBUGPROC=/knfs/tests/native/testIOMapping

3. Run the program to debug

   leon@mambo1> /knfs/tests/native/testIOMapping

   The mambo console shows:

   Re-Mapping program /knfs/tests/native/testIOMapping (/knfs/tests/nati ), k42 pid 0x25 linux pid 0x14e.
   18:01:16: 78790277912: (1765712825): breakpoint pid 0x25, progName -bash
   WARNING: 78790283561: Static breakpoint at 0x00001000702BFFE0; waiting for gdb
   WARNING: 78790283561: MCM 0 waiting for GDB to attach on port 44911

4. Start the debugger on .dbg program file

   powerpc64-linux-gdb powerpc/partDeb/usr/testIOMapping.dbg

   powerpc64-linux-gdb is provided with the k42 devkit debian package
   If you like xemacs, use my custom.el file and type ESC-x ppc-gdb

5. Attach debugger to machine:port

   (gdb) mambo-debug s3:44911

   See definition of mambo-debug in .gdbinit file

6. Set breakpoints
7. Continue execution and start debugging the program

   (gdb) cont

• On the target machine (where mambo is running):
  1. Find mambo's pid:

     ps -fea | grep systemsim

  2. Run gdbserver:

     gdbserver :<port> --attach <mambo_pid>
     # Example: 
     gdbserver :45000 --attach 13217

• On the client machine (where I want to run gdb):
  1. Run gdb

     gdb systemsim

  2. Attach to remote machine

     gdb> target remote <target_host>:<port>
     # Example:  
     target remote s1:45000

• Xemacs init file (~/.xemacs/custom.el)

(defun ppc-gdb (path)
  (interactive "fRun mambo-gdb on file: ")
  
  (let (gdb-command-name)
    (setq gdb-command-name "powerpc64-linux-gdb")
    (gdb (if (string-match "XEmacs\\|Lucid" emacs-version)
             path
           (concat gdb-command-name " " path)))))

• Gdb init file (~/.gdbinit)

#
# mambo stuff
#
 
define mambo-debug
  set architecture powerpc:a35
  set single-step-mode 1
  target remote $arg0
end
document mambo-debug
Attach to mambo simulator to debug a program.
Specify communication method via socket ([host]:<port>) or TTY.
end
 
define libexec
add-symbol k42.29/powerpc/partDeb/lib/exec.so.dbg
end
 
define libk42sys
add-symbol k42.29/powerpc/partDeb/lib/libk42sys.so.1.dbg
end
 
define z
  stepi
  x/i $pc
end
 
define zn
  nexti
  x/i $pc
end
 
set radix 10