Making a Debuggable Kernel

Making a Debuggable Kernel

To make a kernel that you can debug from symmon(1), you need to create a kernel slightly different from the standard one. Use the following steps (many of which you used when you added a device driver to the kernel) to create a debuggable kernel.

Become root:
% su
Edit /var/sysgen/system/irix.sm.
- Change the line:
  EXCLUDE idbg
  to
  
  INCLUDE idbg
- Find the two lines containing LDOPTS toward the end of the file. Comment out the uncommented lines and remove the comment marker for the currently commented out lines. (To comment out a line, put an asterisk character in the first column.)
- Make a note of the change. When you are finished debugging, undo the change so that you can make a standard kernel.
Copy the current kernel to a safe place before rebooting.
# cp /unix /unix.orig or # ln /unix /unix.orig
Run /etc/autoconfig and answer yes if prompted.
Use halt to bring the system down. When you issue the halt command, the system overwrites the current kernel, /unix, with the kernel you have just created, /unix.install.
# halt
On IRIS-4D/100, 4D/200, 4D/300, and 4D/400 Series workstations, set the front panel dip switches as shown in Figure 10-1.
Caution: For these workstations, you must not use any odd-numbered port connected to a CPU for data transfer because an inadvertent
<ctrl-A> in the data stream can put the system into symmon. This is true of any odd-numbered port not connected to a 6-port serial card.
Personal IRIS, Indigo, Indigo2, Indy, Crimson, CHALLENGE/Onyx, and POWER CHALLENGE/POWER Onyx systems do not require physical switches for kernel debugging.

Figure 10-1 : IRIS Front Panel Dip Switches

After halting the system, push the <Reset> button to force the processor to read the switches.