Parameters for the IRXINITX exit

The parameter list for IRXINITX is the same as the parameter list for the IRXINIT initialization routine. TSO/E REXX passes the address of an environment block in register 0. In register 1, TSO/E REXX passes the address of a parameter list, which consists of a list of addresses. Each address in the parameter list points to a parameter.

TSO/E REXX passes the addresses of at least the first seven parameters. The addresses that point to parameter 8 and parameter 9 are optional. The high-order bit of the last address in the parameter list is set to 1 to indicate the end of the parameter list. Table 1 describes the parameter list that IRXINITX receives.

Table 1. Parameters for the IRXINITX exit
Parameter	Number of bytes	Description
Parameter 1	8	This parameter specifies the function to be performed: INITENVB -- to initialize a new environment. FINDENVB -- to obtain the address of the environment block for the current non-reentrant environment. FINDENVB returns the address of the environment block in register 0 and in parameter 6. It does not initialize a new environment.
Parameter 2	8	The name of the parameters module, which contains the values for initializing the new environment. On the call to the IRXINIT initialization routine, the caller may have passed a blank in this field. Therefore, IRXINIT assumes that all the fields in the parameters module are null. The parameters module is described in Characteristics for a language processor environment. IRXINIT provides two ways in which you can pass parameter values; the parameters module and the address of an in-storage parameter list, which is parameter 3.
Parameter 3	4	The address of an in-storage parameter list, which is an area in storage containing parameters that are equivalent to the parameters in the parameters module. The format of the in-storage list is identical to the format of the parameters module. This parameter may be 0. If the address is 0, IRXINIT assumes that all fields in the in-storage parameter list are null.
Parameter 4	4	The address of a user field. IRXINIT does not use or check this pointer or the field. You can use this field for your own processing.
Parameter 5	4	A 4-byte field that is reserved.
Parameter 6	4	This parameter is only used for output by IRXINIT and should not be altered by this exit. It contains the address of the environment block. If you use the FINDENVB parameter to locate an environment, this parameter contains the address of the environment block for the current non-reentrant environment. If you use INITENVB to initialize a new environment, IRXINIT returns the address of the environment block for the newly created environment in this parameter. For either FINDENVB or INITENVB, IRXINIT also returns the address of the environment block in register 0. This parameter lets higher-level languages obtain the environment block address to examine information in the environment block.
Parameter 7	4	This parameter is only used for output by IRXINIT and should not be altered by this exit. IRXINIT returns a reason code in this field, which indicates why the requested function did not complete successfully. describes the reason codes that may be returned.
Parameter 8	4	Parameter 8 is an optional parameter that lets you specify how REXX obtains storage in the language processor environment. Specify 0 if you want the system to reserve a default amount of storage workarea. If you want to pass a storage workarea to IRXINIT, specify the address of an extended parameter list. The extended parameter list consists of the address (a fullword) of the storage workarea and the length (a fullword) of the workarea, followed by X'FFFFFFFFFFFFFFFF'. For more information on how REXX obtains workarea storage, see .
Parameter 9	4	This parameter is only used for output by IRXINIT and should not be altered by this exit. It is a 4-byte field that IRXINIT uses to return the return code.