Methods to Invoke HCD Functions

You can select from the following alternatives to invoke the HCD functions:

  1. You can use the CBDMGHCP command together with an input parameter string that specifies the desired function and other required parameters. The format of this command is as follows:
    HCD Function Invocation
    Read syntax diagramSkip visual syntax diagramOSRUNCBDMGHCPPARM='Input Parameter String'

    However, before you can launch this command, you have to specify the required FILEDEF statements. For formats of the input parameter strings and the used FILEDEF DD names see the sections where each HCD function is described in more detail.

    Note: For the HCD function Generate CP I/O configuration file from active system configuration (see Generate I/O Configuration File from Control Blocks (CBDSRDEV)), CBDMGHCP is not invoked.
  2. Another possibility for invoking the HCD functions is to use an ATTACH or LINK module programming statement to invoke the module CBDMGHCP.

    When you invoke the module, register 1 must contain the address of a two-word parameter list.

    Word 1
    Address of input parameter (see Input Parameter String), preceded by a two byte length field.
    Word 2
    Address of a list of alternate DD names. If not used, the address must be binary zero. For the list format of alternate DD names see List of Alternate DD Names.

    You may overwrite standard DD names listed in Table 1 as desired before invoking HCD.

    Note: Trailing commas in the parameter string can be omitted.
  3. For the available HCD functions, a REXX utility is shipped with z/VM HCD which you can use on your z/VM system to invoke the desired HCD functions (see List of Available HCD Functions). The provided REXX utilities can be customized to fit your needs, but this is not recommended. The invocation interface for these utilities is included in the sections where the single HCD functions are described.

    The advantage of the utilities is that they compose the OSRUN statement with the appropriate input parameter string for the desired function. Also, the utilities establish the appropriate FILEDEF statements and clear them after completion.