Motorola MVME166IG/D2, MVME166D2 manual Bootbug, 166BBug Implementation

BOOTBUG

6.Power up the system. 166Bug executes some self-checks and displays the debugger prompt "166-Bug>" (if 166Bug is in Board Mode). However, if the ENV command (Appendix A) has put 166Bug in System Mode, the system performs a selftest and tries to autoboot. Refer to the ENV and MENU commands. They are listed in Table 4-3.

If the confidence test fails, the test is aborted when the first fault is encountered. If possible, an appropriate message is displayed, and control then returns to the menu.

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BOOTBUG

166BBug Implementation

The MVME166 board has a byte-wide EPROM in addition to the Flash memory used to contain the debugger and diagnostics firmware. The EPROM supplied contains the BootBug product (166BBug). Since Flash memory can be electronically erased, the firmware contained in this EPROM is a miniature version of the regular debugger product. It contains enough functionality to enable downloading of object code (by means of the VMEbus, serial port, SCSI bus, or the network) and reprogramming of the Flash memory.

The following table lists the the new commands available in the 166BBug product.

Command	Description
EXEC	Execute User Program
SETUP	Set "System" Parameters

Detailed descriptions of additional subset commands can be found in the Debugging Package for Motorola 68K CISC CPUs User’s Manual.

There is a jumper on the MVME166 board that controls the operation of the BootBug. If the jumper at J3 pins 7 and 8 is in place (GPI3), then the BootBug (which always executes at reset and powerup) will unconditionally jump to the debugger product contained in the Flash memory. If this jumper is removed, execution will continue in the (diminished functionality) BootBug.

Before using some of the features of the MVME166 BootBug, some parameters may need to be defined. For example, the SCSI ID, the Ethernet address, the clock speed of the board, or possibly the mapping of VMEbus. There is a new command provided for this purpose, the setup command. You should run this command and answer the prompts to be sure the board is configured properly before using any SCSI, VME, or Ethernet I/O.

MVME166IG/D2 3-7