When IRXINIT initializes a language processor environment, IRXINIT
creates several control blocks that contain information about the
environment. One of the control blocks is the parameter block (PARMBLOCK).
The parameter block contains
the parameter values that IRXINIT used to define the environment,
that is, the parameter block contains the characteristics that define
the environment. The block also contains the addresses of the module
name table, the host command environment table, and the function package
table, which contain additional characteristics for the environment.
TSO/E provides three default
parameters modules, which are
load modules that contain the values for initializing
language processor environments. The
three default modules are IRXPARMS (MVS™),
IRXTSPRM (TSO/E), and
IRXISPRM (ISPF).
Values provided in the three default parameters modules shows
the default values that TSO/E provides in each of these modules.
A parameters module consists of the parameter block (PARMBLOCK), the
module name table, the host command environment table, and the
function package table.
Figure 1 shows
the format of the parameters module.
Table 1 shows the format
of PARMBLOCK. Each
field is described in more detail following the table. The end of
the PARMBLOCK must be indicated by X'FFFFFFFFFFFFFFFF'.
The format of the module name table, host command environment table,
and function package table are described in subsequent topics.
The following information describes each field in the PARMBLOCK.
If you change any of the default parameters modules that TSO/E provides
or you use IRXINIT to initialize a language processor environment, read Changing the default values for initializing an environment, which provides information about
changing the different values that define an environment.
- ID
- An 8-byte character field that is used only to identify the parameter
block that IRXINIT creates. The field name is ID.
The value that
TSO/E provides in the three default parameters modules is IRXPARMS.
You must not change the value in the ID field in any of the parameters
modules.
- Version
- A 4-byte character field that identifies the version of the parameter
block for a particular release and level of TSO/E. The field name
is VERSION.
The value that TSO/E provides in the three default
parameters modules is 0200. You must not change the Version field
in any of the parameters modules.
- Language Code
- A 3-byte field that contains a language code. The
field name is LANGUAGE.
The language code identifies
the language in which REXX messages are displayed. The default that
TSO/E provides in all three parameters modules is ENU, which is the
language code for US English in mixed case (upper and lowercase).
The possible values are:
- CHS – Simplified Chinese
- CHT – Traditional Chinese
- DAN – Danish
- DEU – German
- ENP – US English in uppercase
- ENU – US English in mixed case (upper and lowercase)
- ESP – Spanish
- FRA – French
- JPN – Japanese (Kanji)
- KOR – Korean
- PTB – Brazilian Portuguese
- Reserved
- A 1-byte field that is reserved.
- Module Name Table
- A 4-byte field that contains the address of the module name table.
The field name is MODNAMET.
The table contains the ddnames for
reading and writing data and for loading REXX execs, the names of
several replaceable routines, and the names of several exit routines.
Module name table describes the table in detail.
- Host Command Environment Table
- A 4-byte field that contains the address of the host command environment
table. The field name is SUBCOMTB.
The table contains the names
of the host command environments for processing host commands. These
are the environments that REXX execs can specify using the ADDRESS
instruction. Commands to external environments describes
how to issue host commands from a REXX exec and the different environments
TSO/E provides for command processing.
The table also contains
the names of the routines that are invoked to handle the processing
of commands that are issued in each host command environment. Host command environment table describes the table in detail.
- Function Package Table
- A 4-byte field that contains the address of the function package
table for function packages. The field name is PACKTB. Function package table describes the table in detail.
- Token for PARSE SOURCE
- An 8-byte character string that contains the
value of a token that the PARSE SOURCE instruction uses. The field
name is PARSETOK. The default that TSO/E provides in all three parameters
modules is a blank.
This token is the last token of the string
that PARSE SOURCE returns. Every PARSE SOURCE instruction processed
in the environment returns the token.
- Flags
- A
fullword of bits that IRXINIT uses as flags. The field name is FLAGS.
The flags define certain characteristics for the new language processor environment and how
the environment and execs running in the environment operate.
In
addition to the flags field, the parameter following the flags is
a mask field that works together with the flags. The mask
field is a string that has the same length as the flags field. Each
bit position in the mask field corresponds to a bit position in the
flags field. IRXINIT uses the mask field to determine whether it
should use or ignore the corresponding flag bit.
See Mask for
a description of the bit settings for the mask field and how the value
for each flag is determined.
Table 2 summarizes
each flag. Flags and corresponding masks describes each
of the flags in more detail and the bit settings for each flag. The
mapping of the parameter block (PARMBLOCK) includes the mapping of
the flags. TSO/E provides a mapping macro IRXPARMB for the parameter
block. The mapping macro is
in SYS1.MACLIB.
- Mask
- A fullword of bits that IRXINIT uses as a mask for
the setting of the flag
bits. SeeFlags for a description of the flags field.
The
field name is MASKS. The mask field is a string that has the same
length as the flags field. Each bit position in the mask field corresponds
to a bit in the same position in the flags field. IRXINIT uses the
mask field to determine whether it should use or ignore the corresponding
flag bit. For a given bit position, if the value in the mask field
is:
- 0 — the corresponding bit in the flags field is ignored (that
is, the bit is considered null)
- 1 — the corresponding bit in the flags field is used.
- Subpool Number
- A fullword that specifies the number of the subpool (in binary)
in which storage is allocated
for the entire language processor environment.
The field name is SUBPOOL. The default value in the IRXPARMS module
is 0. The value can be from 0 to 127 in decimal.
In the IRXTSPRM
and IRXISPRM modules, the default is 78 (in decimal). For environments
that are integrated into TSO/E (see Types of environments - integrated and not integrated into TSO/E),
the subpool number must be 78.
- Address Space Name
- An 8-byte character field that specifies the name
of the address space.
The field name is ADDRSPN. TSO/E provides the following defaults:
- IRXPARMS module – MVS
- IRXTSPRM module – TSO/E
- IRXISPRM module – ISPF
- X'FFFFFFFFFFFFFFFF'
- The end of the parameter block is indicated by X'FFFFFFFFFFFFFFFF'.