pdc(1M)pdc(1M)NAMEpdc - processor-dependent code (firmware)
DESCRIPTION
is the firmware that implements all processor-dependent functionality,
including initialization and self-test of the processor. Upon comple‐
tion, it loads and transfers control to the initial system loader
(isl(1M)). Firmware behavior varies somewhat, depending on the hard‐
ware as described below.
To load from an external medium, must know the particular device on
which resides. Typically the device is identified by the Primary Boot
Path that is maintained by 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 com‐
plete, reads the Console Path from Stable Storage, and attempts to ini‐
tialize the console device. If the initialization fails, attempts to
find and initialize a console device. Algorithms used to find a con‐
sole device are model-dependent. then announces the Primary Boot,
Alternate Boot, and Console Paths.
If (see isl(1M)) is enabled, provides a 10-second delay, during which
time the operator can override the sequence by typing any character on
the console. If the operator does not interrupt this process, initial‐
izes and reads from the Primary Boot Path. On models that support
autosearch, if this path is not valid and (see isl(1M)) is enabled,
then searches to find a bootable medium.
If allowed to complete, a list of potentially bootable devices is dis‐
played, 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 identi‐
fier, 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
If the sequence is unsuccessful, overridden by the operator, or not
enabled in the first place, 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 and
enable can be modified via
SEE ALSOboot(1M), isl(1M).
PA-RISC Systems Only pdc(1M)
