Using SCODB

Source code line numbers

SCODB can display source code line numbers in the disassembly listing. To enable this feature, recompile the desired source modules with the -g option to the cc(CP) command. With some compilers, code compiled with the -g option is not optimized. You may also need to modify the value of the LINETB tunable parameter; see ``Modifying tunable parameters''.

After the kernel has been successfully relinked, the source line numbers automatically appear when disassembling a recompiled module, as the following example shows:

   s_trap+39       call    ageprocess               ; line 222
   s_trap+3E       cmpb    agecntl,0                ; line 223
   s_trap+45       je      s_trap+6C
   s_trap+47       movl    %eax,tune                ; line 224

Use the ``/'' and ``?'' pattern search commands to position yourself at a particular source line when in the disassembly mode. For example, typing /line<Space>238 searches forward for the next instruction marked as source line 238. Note that this will fail if there is no instruction associated with that line number.