Tornado

Tornado 2.0
User’s Guide
5.2.6 Using the Shell for System Mode Debugging
The bulk of this chapter discusses the shell in its most frequent style of use:
attached to a normally running VxWorks system, through a target agent running
in task mode. You can also use the shell with a system-mode agent. Entering
system mode stops the entire target system: all tasks, the kernel, and all ISRs.
Similarly, breakpoints affect all tasks. One major shell feature is not available in
system mode: you cannot execute expressions that call target-resident routines.
You can still spawn tasks, but bear in mind that, because the entire system is
stopped, a newly-spawned task can only execute when you allow the kernel to run
long enough to schedule that task.
Depending on how the target agent is configured, you may be able to switch
between system mode and task mode; see 4.6 Configuring the Target-Host
Communication Interface, p.137. When the agent supports mode switching, the
following WindSh commands control system mode:
sysSuspend( )
Enter system mode and stop the target system.
sysResume( )
Return to task mode and resume execution of the target system.
The following commands are to determine the state of the system and the agent:
agentModeShow( )
Show the agent mode (system or task).
sysStatusShow( )
Show the system context status (suspended or running).
The following shell commands behave differently in system mode:
b( )
Set a system-wide breakpoint; the system stops when this breakpoint is
encountered by any task, or the kernel, or an ISR.
c( )
Resume execution of the entire system (but remain in system mode).
i( )
Display the state of the system context and the mode of the agent.
s( )
Single-step the entire system.
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