SVC 99, DYNALLOC

INPUT
Register 1

Address of request parameter block pointer

OUTPUT
Register 15

Return code:

0=Successful

Any other value indicates an error. For further details see the IBM manual MVS Programming: Authorized Assembler Services Guide GC28-1763.

Request parameter block pointer (S99RBPTR): Holds the 31-bit address of the request parameter block). High-order bit must be set on.

Request parameter block (S99RB), 20 bytes in length.

Bytes Description
0 Length of request block (always 20 bytes)
1

One-byte verb code:

x'01' Data set name allocation

x'02' Data set name deallocation

x'03' Not supported

x'04' Not supported

x'05' Not supported

x'06' Not supported

x'07' DD name allocation

2-3 2-byte flag field
4-5 2-byte error code field
6-7 2-byte information code field
8-9 Address of text unit parameter list
12-15 Address of request block extension
16-19 4-byte flag field

Text unit parameter list (S99TUPL): array of 31-bit addresses with each address pointing to one text unit. Last address must have high-order bit set.

Text unit (S99TUNIT): data structure containing the following fields:

Bytes Field Description
0-1 Key Contains hexadecimal code indicating which function is being requested
2-3 Number Number of length and parameter combinations in the text unit (the next two fields)
Length The length of the following parameter field
Parameter A variable-length field containing input information specific to the particular key function being requested

Request parameter block extension (S99RBX), 34 bytes in length.

Bytes Description
0-5 Identifier string ' S99RBX'
6 Version number
7 Processing options
8 Message block subpool number
9 Storage key
10 Severity level
11 Severity level
12 Number of message blocks
13-16 CPPL address
17-18 Reserved
19 Message processing reason code
20 Message block freeing reason code
21-24 PUTLINE or WTO return code
25-28 Message block chain address
29-30 Information retrieval error code
31-32 Erroneous information retrieval key
33 SMS reason code
Note: You should use the equates and DSECTs provided by the IBM macros IEFZB4D0 and IEFZB4D2 to construct the SVC99 parameter structures.