The save area is 128 bytes (
X'80') in length. The first
72 bytes of the save area matches the format of a traditional OS save
area and is provided to called routines for the purpose of saving
general registers. Certain fields are critical to this description
and are included here as well as documenting existing HPCJ usage of
some reserved fields. This existing usage occurs in OS/390® V1R1 and older code.
| Field location |
Field description |
|---|
| X'00' |
STKLANG - Language word |
| X'04' |
CEEDSABACK - Back chain pointer
to previous save area |
| X'08' |
CEEDSAFWD - Forward chain pointer
to next save area |
| X'0C' |
CEEDSASAVE - GPR save area (registers
14 through 12) |
| X'4C' |
CEEDSANAB - Next Available Byte |
| X'78' |
Used by C to save the parm list
address (r1) |
| X'7C' |
Reserved |