Tornado

5
Shell
Example 5-2
sp( )
Add a task to the execution queue. The task does not begin to execute until you
continue the kernel or step through the task scheduler.
The following example shows how to use system mode debugging to debug a
system interrupt.
System-Mode Debugging
In this case, usrClock( )is attached to the system clock interrupt handler which is
called at each system clock tick when VxWorks is running. First suspend the
system and confirm that it is suspended using either i( ) or sysStatusShow( ).
-> sysSuspend
value = 0 = 0x0
->
-> i
NAME ENTRY TID PRI STATUS PC SP ERRNO DELAY
--------- ---------- -------- ----- ------- ------- ------- ----- -----
tExcTask _excTask 3e8f98 0 PEND 47982 3e8ef4 0 0
tLogTask _logTask 3e6670 0 PEND 47982 3e65c8 0 0
tWdbTask 0x3f024 398e04 3 PEND 405ac 398d50 30067 0
tNetTask _netTask 3b39e0 50 PEND 405ac 3b3988 0 0
Agent mode : Extern
System context : Suspended
value = 0 = 0x0
->
-> sysStatusShow
System context is suspended
value = 0 = 0x0
Next, set the system mode breakpoint on the entry point of the interrupt handler
you want to debug. Since the target agent is running in system mode, the
breakpoint will automatically be a system mode breakpoint, which you can
confirm with the b( ) command. Resume the system using c( ) and wait for it to
enter the interrupt handler and hit the breakpoint.
-> b usrClock
value = 0 = 0x0
-> b
0x00022d9a: _usrClock Task: SYSTEM Count: 0
value = 0 = 0x0
-> c
value = 0 = 0x0
->
Break at 0x00022d9a: _usrClock
Task: SYSTEM
You can now debug the interrupt handler. For example, you can determine which
task was running when system mode was entered using taskIdCurrent( ) and i( ).
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