Motorola MVME162P-242, Installation And Use Manual

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Bringing up the Board
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Then remove the jumper from J16 (if you wish to disable
subsequent Flash writes) and slide switch S4 segment 5 back to
OFF
. (162Bug always executes from memory location FF800000;
the setting of S4 determines whether that location is in EPROM
or Flash.)
Autoboot
Autoboot is a software routine that is contained in the 162Bug
Flash/EPROM to provide an independent mechanism for booting an
operating system. This autoboot 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. Controllers, devices, and their LUNs
are listed in Appendix D.
At power-up, Autoboot is enabled and (provided that the drive and
controller numbers encountered are valid) the following message is
displayed upon the system console:
Autoboot in progress... To abort hit <BREAK>
A delay follows this message so that you can abort the Autoboot process if
you wish. Then the actual I/O begins: the program designated within the
volume ID of the media specified is loaded into RAM and control passes
to it. If you want to gain control without Autoboot during this time,
however, you can press the <BREAK> key or the software
ABORT
or
RESET
switches.
The Autoboot process is controlled by parameters contained in the ENV
command. These parameters allow the selection of specific boot devices
and files, and allow programming of the Boot delay. Refer to the ENV
command description in Chapter 3 for more details.