ZCOM Tables and Data Structures

ZCOM Header Structure

This pointer contains the starting physical kernel memory address of the ZCOM subsystem memory. It is initialized to zero by TTGEN. ZMON initializes it with the memory address while loading the memory tables into kernel memory. It is a 64-bit value when used in a 64-bit kernel.

HSSIZE - Total runtime system size in bytes

This is the total size in bytes of the ZCOM subsystem memory, including all tables, queue headers, and the buffer pool.

HBPSIZE - Buffer pool size in bytes

This is the size in bytes of the ZCOM buffer pool. It is defined by the

Buffer-Poolparameter in the TTGEN configuration file.

HNDMAX - Number of node entries

This contains the maximum number of node entries which may exist in the node entries memory section. This value is defined by the Node-Entrykeyword in the TTGEN configuration file. Each Local-Nodeand Remote-Nodedefinition consumes one node table entry.

HZLMAX - Total number of ZLUs

Total number of terminal ZLUs and spare (i.e., program) ZLUs. That is, this is the combined values of the Program-ZLU and Terminal-ZLU parameters specified in the TTGEN configuration file.

HTMZLU - Number of terminal ZLUs

This is the number of ZLUs out of the total (HZLMAX) that are allocated to terminals. The terminal ZLU numbers are allocated from 1 up to the number specified in this field. The TTGEN Terminal-ZLUparameter is used to initialize this field.

HSPZLU - Number of program ZLUs

Total number of available program ZLUs. The TTGEN Program-ZLUparameter is used to initialize this field.

HSPZL1 - First program ZLU number

Number of the first ZLU not allocated to terminal ZLUs. This field is initialized to the value of the TTGEN parameter Terminal-ZLU+ 1. It indicates where the program ZLUs begin within the ZLU Table. Note that program ZLUs are assigned from the range (Terminal-ZLU+1) to (Terminal-ZLU+ Program-ZLU).

46

Chapter 3