Motorola MVME187 User Manual

4-8

Debugger General Information

For a user's ROMboot module to gain control through the 
ROMboot linkage, four requirements must be met: 

For complete details on how to use ROMboot, refer to the 
Debugging Package for Motorola 88K RISC CPUs User's Manual. 

Network Auto Boot is a software routine contained in the 187Bug 
EPROMs that provides a mechanism for booting an operating 
system using a network (local Ethernet interface) as the boot device.

1. 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. 

2. 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.) 

Power must have just been 
applied.

Change this to respond to any reset.

Your routine must be located 
within the MVME187 ROM 
memory map.

Change this to any other portion of the onboard 
memory, or even offboard VMEbus memory.

The ASCII string ÒBOOTÓ must be located within the speciÞed memory range.

Your routine must pass a checksum test, which ensures that this routine was really 
intended to receive control at powerup.