Using Macro ICVEDT02 to Map the Extents Area

The ICVEDT02 mapping macro is used to map the extent area when you use the CVAFDSM macro and specify RTA4BYTE=YES for indexed VTOCs or nonindexed VTOCs.

The format of the ICVEDT02 mapping macro follows.

Table 1. Format of ICVEDT02 Mapping Macro
Offset	Bytes	Name	Description
0 (X'00')	8	DT2X7EYE	Identifier="ICVEDT02"
8 (X'08')	4	DT2X7LEN	Length of ICVEDT02.
12 (X'0C')	1	DT2X7LEV	Level number.
13 (X'0D')	1	DT2X7FLG	Flag byte.
14 (X'0E')	2	DT2X7NF0	Number of format-0 DSCBs created.
16 (X'10')	5	DT2X7CSR	CCHHR cursor field. Used by the system. Initialized to zero by caller—then do NOT modify.
21 (X'15')	3	DT2X7RES	Reserved.
24 (X'18')	4	DT2X7RTA	Relative Track Address (RTA) cursor field. Used by the system. Initialized to zero by caller—then do NOT modify.
28 (X'1C')	4	DT2X7RE2	Reserved.
32 (X'20')	4	DT2X7ENT	Number of extent descriptor entries.
-	-	-	Extent descriptor array.
36 (X'24')	8	DT2ENTRY	One entry for each extent.
-	4	DT2RTAST	RTA of start of extent
-	4	DT2RTAED	RTA+1 of end of extent