Booting Operating Systems; Boot System Selection; Unattended Operation; Attended Operation - HP 9000 Series 310 Service Information Manual

Booting Operating Systems
Boot System Selection
The Boot ROM provides two modes of operation, attended and unattended. These two modes
allow a user to either select from multiple operating systems on multiple boot devices or to
automatically boot an operating system with no user intervention.
Unattended Operation
In an Unattended situation, the first operating system found will be loaded and given control.
To find an OS, the Boot ROM will search a boot list of prioritized devices. The first OS system
found on one of these devices will be booted. If none is found, the boot list will be searched
again until a one is found. This allows discs not present at power-up to be found after their
initialization is complete.
Once a device has been successfully accessed, it will never be accessed again until re-power-up
or a reset. This mininlizes wear on mass storage devices and limits the confusion of operating
systems disappearing and re-appearing on shared resource management systems.
To force the boot of a particular system when the machine is unattended, the user has the
following options:
• Make sure that the OS to be booted is the first to be found according to the boot list
search. This is quite easy to do sirnply by changing device addresses, select codes, or OS
names, or by moving OSs. The prioritized boot list is discussed in detail latter in this
section .
• On an SRM with multiple OSs, make the first OS to be found one that looks at the host's
SRM node address and uses the node address to decide what secondary OS to boot. (The
Boot ROM can then be called to boot a particular OS.)
Attended Operation
To force the boot of an OS not chosen by the boot list, the user must enter Attended Operation
Mode. This mode is entered by pressing the space bar,
I
RETURN
I,
or any letter or number during
power-up after the input portion of the hurnan interface (i.e., the keyboard or terminal) has been
initialized but before a default OS is booted. A good way to do this is to hold down the space
bar until the OS selection menu is seen. This will cause a boot selection menu to be displayed.
A user can be sure that the input human interface has been initialized when one of the following
(depending on the hurnan interface provided) is displayed in the self-test list:
Keyboard
Console Keyboard at XX
HP 986XX at X
w here XX is the lowest select code of key board electronics
in an I/O slot.
w here the Xs are the type and select code of the remote
human interface.
Boot Rom Functions
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