HP-UX Reference (11i v1 00/12) - 1M System Administration Commands N-Z (vol 4)

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STANDARD Printed by: Nora Chuang [nchuang] STANDARD
/build/1111/BRICK/man1m/naaagt.1m
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p
pdc(1M) pdc(1M)
NAME
pdc - processor-dependent code (firmware)
DESCRIPTION
pdc is the firmware that implements all processor-dependent functionality, including initialization and self-
test of the processor. Upon completion, it loads and transfers control to the initial system loader (isl(1M)).
Firmware behavior varies somewhat, depending on the hardware series as described below.
Series 800 Behavior
To load isl from an external medium, pdc must know the particular device on which isl resides. Typically
the device is identified by the Primary Boot Path that is maintained by pdc in Stable Storage. A path
specification is a series of decimal numbers each suffixed by ’/’, indicating bus converters, followed by a
series of decimal numbers separated by ’.’, indicating the various card and slot numbers and addresses. The
first number, not specifying a bus converter, is the MID-BUS module number (that is, slot number times
four) and followed by the CIO slot number. If the CIO slot contains a terminal card, the next number is the
port number, which must be zero for the console.
When the processor is reset after initialization and self-test complete, pdc reads the Console Path from
Stable Storage, and attempts to initialize the console device. If the initialization fails, pdc attempts to find
and initialize a console device. Algorithms used to find a console device are model-dependent. pdc then
announces the Primary Boot, Alternate Boot, and Console Paths.
If autoboot (see isl(1M)) is enabled, pdc provides a 10-second delay, during which time the operator can
override the autoboot sequence by typing any character on the console. If the operator does not interrupt
this process, pdc initializes and reads isl from the Primary Boot Path. On models that support autosearch,
if this path is not valid and autosearch (see isl(1M)) is enabled, pdc then searches through the
MID-BUS
modules and CIO slots to find a bootable medium. Currently, autosearch is only implemented on the model
825.
If the autoboot sequence is unsuccessful, overridden by the operator, or not enabled in the first place, pdc
interactively prompts the operator for the Boot Path to use. Any required path components that are not
supplied default to zero.
The Primary Boot, Alternate Boot, and Console Paths as well as autoboot and autosearch enable can be
modified via isl.
Series 700 Behavior
To load isl from an external medium, pdc must know the particular device on which isl resides. Typically
the device is identified by the Primary Boot Path that is maintained by pdc in Stable Storage. A path
specification is an
I/O subsystem mnemonic that varies according to hardware model.
When the processor is reset after initialization and self-test complete, pdc reads the Console Path from
Stable Storage, and attempts to initialize the console device. If the initialization fails, pdc attempts to find
and initializea console device. Algorithms used to find a console device vary according to hardware model.
If autoboot and autosearch (see isl(1M)) are enabled, pdc waits for approximately 10 seconds during which
time the operator can override the autoboot sequence pressing and holding the
ESC (escape) key on the con-
sole.
The system then begins a search for potentially bootable devices. If allowed to complete, a list of poten-
tially bootable devices is displayed, labeled with abbreviated path identifiers (P0, P1, etc). A simple menu is
then displayed where the user can:
• Boot a specific device, using the abbreviated path identifier, or the full mnemonic.
• Start a device search where the contents are searched for IPL images (note the first search only
identified devices and did not check the contents).
• Enter the boot administration level.
• Exit the menu and return to autobooting
• Get help on choices
The search of potentially bootable devices can be aborted by pressing and holding the escape key. The
search for device contents can also be aborted by pressing and holding the escape key.
If the operator does not interrupt the search process, pdc initializes and reads isl from the Primary Boot
Path.
HP-UX Release 11i: December 2000 − 1 − Section 1M−−629
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