Motorola MVME162 User Manual
ROMboot
MVME162IG/D2
3-7
3
C
aution
Although streaming tape can be used to autoboot, the same
power supply must be connected to the streaming tape
drive, controller, and the MVME162. At power-up, the tape
controller will position the streaming tape to load point
where the volume ID can correctly be read and used.
power supply must be connected to the streaming tape
drive, controller, and the MVME162. At power-up, the tape
controller will position the streaming tape to load point
where the volume ID can correctly be read and used.
If, however, the MVME162 loses power but the controller
does not, and the tape happens to be at load point, the
sequences of commands required (attach and rewind)
cannot be given to the controller and autoboot will not be
successful.
does not, and the tape happens to be at load point, the
sequences of commands required (attach and rewind)
cannot be given to the controller and autoboot will not be
successful.
ROMboot
As shipped from the factory, 162Bug occupies the first half of the Flash
memory. This leaves the second half of the Flash memory and the PROM
socket (U47) available for your use. The 162Bug is also available in PROM if
your application requires all of the Flash memory. Contact your Motorola sales
office for assistance. This function is configured/enabled by the Environment
(ENV) command (refer to Appendix A) and executed at power-up (optionally
also at reset) or by the RB command assuming there is valid code in the
memory devices (or optionally elsewhere on the module or VMEbus) to
support it. If ROMboot code is installed, a user-written routine is given control
(if the routine meets the format requirements). One use of ROMboot might be
resetting SYSFAIL* on an unintelligent controller module. The NORB
command disables the function.
memory. This leaves the second half of the Flash memory and the PROM
socket (U47) available for your use. The 162Bug is also available in PROM if
your application requires all of the Flash memory. Contact your Motorola sales
office for assistance. This function is configured/enabled by the Environment
(ENV) command (refer to Appendix A) and executed at power-up (optionally
also at reset) or by the RB command assuming there is valid code in the
memory devices (or optionally elsewhere on the module or VMEbus) to
support it. If ROMboot code is installed, a user-written routine is given control
(if the routine meets the format requirements). One use of ROMboot might be
resetting SYSFAIL* on an unintelligent controller module. The NORB
command disables the function.
For a user’s ROMboot module to gain control through the ROMboot linkage,
four requirements must be met:
four requirements must be met:
a.
Power must have just been applied (but the ENV command can change
this to also respond to any reset).
this to also respond to any reset).
b. Your routine must be located within the MVME162 Flash/PROM memory
map (but the ENV command can change this to any other portion of the
onboard memory, or even offboard VMEbus memory).
onboard memory, or even offboard VMEbus memory).
c.
The ASCII string "BOOT" must be located within the specified memory
range.
range.
d. Your routine must pass a checksum test, which ensures that this routine
was really intended to receive control at power-up.
For complete details on how to use ROMboot, refer to the Debugging Package
for Motorola 68K CISC CPUs User’s Manual.
for Motorola 68K CISC CPUs User’s Manual.