Mainframe Access uses the IBM utility module IGZERRE to set up the COBOL environment when working with Mainframe Call Generator.
On entry to IGZERRE, the following register contents must exist:
| Register | Contents |
|---|---|
| 1 | If initializing, a function code of 1. If terminating, a function code of 2 If parm list form, the address of a pointer to a word containing the function code as above. |
| 13 | Pointer to standard register save area. |
| 14 | Return address. |
| 15 | IGZERRE's entry address. |
On return, register 15 contains one of the following return codes:
| Return Code | Explanation |
|---|---|
| 0 | Function completed successfully. |
| 4 | COBOL already initialized. This code can only be returned following the use of the initialization function. |
| 8 | Invalid function code in register 1 or parameter list . The function code must be 1 or 2. |
| 12 | ILBOSTP0 not part of load module. This code can only be returned following the initialization of NORES. |
| 16 | COBOL was not previously initialized. This code can only be returned following the use of the termination function. |
| 20 | 20 COBTEST is being used. This code can only be returned following the termination of RES. |
The originally requested function is performed only when the return code is 0.