Data General AViiON 4600 Series, Customer Documentation

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Using the System Control Monitor
B-12
014–002091
BOOT (cont)
Specifying Nonstandard Boot Devices
AViiON device drivers use a particular memory address (or addresses) to access each
device controller. The device specification you use when booting a device includes this
memory location, either explicitly or via device tables. Since the devices supplied by
Data General are preconfigured to default memory-mapped I/O addresses, you do not
explicitly name their addresses. In this appendix, we call these devices at default
addresses
standard boot devices. This Arguments" section of this command
description explains the syntax for booting standard devices.
If you configure devices that are
not listed in Table B-3 or if you do not use the
DG/UX operating system's device drivers, standard device specifications apply only to
the first-stage boot and may not apply at all. This section describes an extended
format for specifying boot devices.
There are several reasons for using the extended, nonstandard-device format for boot
device specifications. You may need to configure a device controller at a different I/O
address than the current Data General convention, or you may have more devices
configured than can be named by the current defaults. You may want to change device
configurations to accommodate your operating system or to configure additional
devices not supplied by Data General.
Without the default parameter values used for standard devices, a boot path
specification is even more complex. The extended format for an SCM boot path
includes information you do not need when specifying standard boot devices. (Your
operating system may store device information in this extended format, however.)
When you use nonstandard boot devices, you need to set configuration jumpers on the
device and include its I/O address as the first parameter (
param1 ) in device
specifications.
The following is the format for an expanded or nonstandard disk or tape boot path
argument:
dev[@vector] [param1],[param2],[param3]
Where Means
dev() The name of the device driver that supports the device.
[@vector] The interrupt vector number, or device code.
[param1] The memory-mapped I/O address of the controller.
[param2] and [param3] Additional parameters, defined by the device driver, to fully
identify the device.
For example: specifies an executable image
called in directory located on the logical disk , the second physical
disk connected to a SCSI adapter at the nonstandard base address FFFFE000; its
device code (interrupt vector) is 70
16
. This example assumes that the device driver
is present, and that it defines each parameter as described.