HP UX 11i v1 I/O Cards manual Zcom Kernel Data, Ncard

ZCOM Tables and Data Structures

ZCOM Kernel Data

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.

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