The ASCRE macro creates an address space. Parameters on the macro
allow you to:
- Name the address space and specify the first program that is to
run in the address space (ASNAME or STPARM parameter).
- Specify an address space initialization routine that ASCRE processing
calls (INIT parameter).
- Provide a routine to control the termination of the address space
(TRMEXIT parameter).
- Provide the termination routine with user data (UTOKEN parameter).
- Pass a parameter list from the creating program to a program in
the new address space (ASPARM or STPARM parameter).
- Assign various attribute to the new address space (ATTR parameter).
- Set up cross memory linkages between the creating address space
and the new address space (AXLIST, TKLIST, and LXLIST parameters).
- Provide an address where ASCRE will return output data (ODA parameter).
The required parameters on the ASCRE macro are ASNAME or STPARM,
INIT, and ODA. Some comments about these parameters are:
- Specify either ASNAME or STPARM.
- ASNAME specifies the address space name, which is also the name
of the procedure that identifies the first program to run in the new
address space.
- STPARM specifies a parameter string. Although the system does
not actually issue a START command, the parameter string consists
of START command parameters. This parameter string must begin with
the name of the address space.
An operator can use the name of the address space on the
DISPLAY A command to display information about the address space.
For the syntax of the DISPLAY command, see z/OS MVS System Commands.
- Output data from the macro appears at the location specified on
the ODA parameter. This data includes two identifiers of the new
address space: the ASCB and the STOKEN. The STOKEN is an identifier
that is unique within the lifetime of an IPL. The format of the output
data area is a 24-byte area that the macro IHAASEO maps as follows:
Offset |
Length |
Description |
---|
X‘00’ |
8 bytes |
The STOKEN of the new address space |
X‘08’ |
4 bytes |
The ASCB of the new address space |
X‘0C’ |
4 bytes |
Basing for IEZEAECB, the mapping macro for the
two ECBs, EAERIMWT and EAEASWT |
X‘10’ |
8 bytes |
Reserved |
For the format of IHAASEO, see the ASEO data area in
See z/OS MVS™ Data Areas in the z/OS® Internet Library: &zosliburl;.
- Although INIT is a required parameter, you might not need to write
an initialization routine. The address space initialization routine can
help you decide whether you need an initialization routine.
Issue the ASCRE macro in a supervisor state program that is executing
in primary or AR address space control (ASC) mode. The caller must
be in enabled and unlocked TCB mode and must not have an enabled unlocked
task (EUT) functional recovery routine (FRR) established. Issue the
ASCRE macro only after system initialization is complete.