Reference Guide

ZCOM Tables and Data Structures
ZCOM Kernel Data
Chapter 3124
ZCOM Kernel Data
This is a kernel data structure shared by the LDM and DAM. Unlike the
ZCOM subsystem memory tables (which are set up when ZCOM
subsystem is started), this data structure is generated into the HP-UX
operating system with the LDM and always exists even when the ZCOM
subsystem is not started up. The kernel entry point for this data
structure is Zcom which consists of four components, NCARD, HPATBL,
SYS, and HP. These components are described below.
NCARD
NCARD (Number of Mux interface cards installed in the system) is a
counter used to indicate the number of Mux interface cards in the host
computer. It is updated by the DAM when the Mux interface cards are
bound to the DAM during system boot-up.
HPA Table
The Hard Physical Address (HPA) table is built by the DAM; for HP-PB
standard systems it provides a cross reference between the hardware
address and software tables and addresses. The DAM creates a row in
this table for each interface card that is bound by the system at bootup or
reconfiguration. When the ZCOM subsystem is initialized, the LDM uses
the information provided by TTGEN in the ZCOM interface table
(INHPA field) to match the actual HPA value. If the LDM is able to find
the matching HPA, it inserts the ZCOM interface table address in the
HPA table.
Each row in the table has entries of the form (zhpa_type) shown in
Table 3-44.
Table 3-44 HPA Table Entries
Field Name Field Description
Field
Type
Size
(Bytes)
hpano HPA value of this interface long 8
resrvd1 Reserved for future use. int 4