Debugger General Information

Network Boot

Network Auto Boot is a software routine contained in the 162Bug Flash/PROM that provides a mechanism for booting an operating system

3using a network (local Ethernet interface) as the boot device. The Network Auto Boot routine 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 a delay to allow you to abort the Auto Boot process if you wish. 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

You 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 your setup/operation parameters in NVRAM. This feature can be used in the event your setup/operation parameters are corrupted or do not meet a sanity check. Refer to the ENV command (Appendix A) for the ROM defaults.

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MVME162 Embedded Controller Installation Guide

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Motorola MVME162 manual Network Boot, Restarting the System