SVC 120

GETMAIN (options RU, RC, VRC and VRU), FREEMAIN (options R, RU, RC, VRC and VRU), and STORAGE

INPUT
Register 0 Number of bytes of memory to obtain or free.
Register 1 Address of memory to free (zero for GETMAIN)
Register 15
Byte Meaning:
0 Zero
1 Key of memory to obtain or free (not supported)
2 Subpool number of memory to obtain or free
3 Option byte: 00 Conditional GETMAIN

01 Conditional FREEMAIN

02 Unconditional GETMAIN

03 Unconditional FREEMAIN

04 Page boundary bit (not supported)

OUTPUT
Register 1 Address of allocated storage if GETMAIN

Register 15 Return code:

0= Memory obtained or freed

4= Memory not obtained or freed