Motorola CPCI-6020 用户手册

33. Executes the configured boot routine, either ROMboot, Autoboot or Network Autoboot.

34. Executes the user interface (displays the PPC-Bug> or PPC-Diag> prompt).

PPCBug is command-driven. It performs its various operations in response to commands 
entered at the keyboard. When the PPC-Bug prompt appears on the screen, the debugger is 
ready to accept debugger commands. When the PPC-Diag prompt appears on the screen, the 
debugger is ready to accept diagnostic commands. To change from one mode to the other, 
enter SD.

Keyboard entries are stored in an internal buffer and only execute after the Return or Enter key 
is pressed. This feature provides time to correct entry errors, if necessary, with the control 
characters described in the PPCBug Firmware Package User’s Manual.

After the debugger executes the command, the prompt reappears. However, if the command 
causes execution of user target code (for example GO) then control may or may not return to 
the debugger, depending on what the user program does. For example, if a breakpoint is 
specified, control returns to the debugger when the breakpoint is encountered during execution 
of the user program. However, the user program can return to the debugger by means of the 
System Call Handler routine RETURN. For more about this, refer to the GD, GO and GT 
command descriptions in the PPCBug Firmware Package User’s Manual.

A debugger command is made up of the following parts:

z

The command name, either uppercase or lowercase (e.g., MD or md)

z

Any required arguments, as specified by command

z

At least one space before the first argument. Precede all other arguments with either a 
space or comma

z

One or more options, precede an option or a string of options with a semicolon (;). 
If no option is entered, the command’s default option conditions are used

The individual debugger commands are listed in the following table. The commands are 
described in detail in the PPCBug Firmware Package User’s Manual.

You can list all the available debugger commands by entering the Help (HE) command alone. 
You can view the syntax (description) for a particular command by entering HE followed by a 
space, followed by the particular command mnemonic (as listed below), followed by a carriage 
return. Remember that help is now available on both the BUG and DIAG side. In addition, 
issuing help on a DIAG test category gives more information about the tests in that category.