Personal Computer User Manual

Debugger General Information
3-6 Installation Guide
3
automatically scans for controllers and devices in a specified sequence until a
valid bootable device containing a boot media is found or the list is exhausted.
If a valid bootable device is found, a boot from that device is started. The
controller scanning sequence goes from the lowest controller Logical Unit
Number (LUN) detected to the highest LUN detected. (Refer to Appendix C
for default LUNs).
At power-up, Network Boot is enabled, and providing the drive and controller
numbers encountered are valid, the following message is displayed upon the
system console:
“Network Boot in progress... To abort hit <BREAK>”
Following this message there is approximately a thirty-second delay while the
debug firmware waits for the various controllers and drives to come up to
speed. Then the actual I/O is begun: the program pointed to within the
volume ID of the media specified is loaded into RAM and control passed to it.
If, however, during this time you want to gain control without Network Boot,
you can press the <BREAK> key or the software ABORT or RESET switches.
Network Auto Boot is controlled by parameters contained in the NIOT and
ENV commands. These parameters allow the selection of specific boot devices,
systems, and files, and allow programming of the Boot delay. Refer to the ENV
command in Appendix A for more details.
Restarting the System
The user can initialize the system to a known state in three different ways:
reset, abort, and break. Each has characteristics which make it more
appropriate than the others in certain situations.
The debugger has a special feature upon a reset condition. This feature is
activated by depressing the RESET and ABORT switches at the same time.
This feature instructs the debugger to use the default setup/operation
parameters in ROM versus the user’s setup/operation parameters in NVRAM.
This feature can be used in the event the user’s setup/operation parameters
are corrupted or do not meet a sanity check. Refer to the ENV command
(Appendix A) for the ROM defaults.
Reset
Pressing and releasing the MVME197LE front panel RESET switch initiates a
system reset. COLD and WARM reset modes are available and are selected by
using the RESET command. By default, 197Bug is in COLD mode. During
COLD reset, a total system initialization takes place, as if the MVME197LE had