qdosmsq:vectors:alhp
Table of Contents
MM_ALLOC/MEM_ALHP - Vector $D8
This vector allocates space in a user heap.
| Call Parameters | Return Parameters | ||
|---|---|---|---|
| D0.L | Unused | D0.L | Error code. |
| D1.L | Number of bytes required. | D1.L | Number of bytes allocated. |
| D2.L | Unused | D2.L | Corrupted. |
| D3.L | Unused | D3.L | Corrupted. |
| A0.L | Pointer to pointer to free space | A0.L | Address of allocated area. |
| A1.L | Unused | A1.L | Corrupted. |
| A2.L | Unused | A2.L | Corrupted. |
| A3.L | Unused | A3.L | Corrupted. |
Errors
| ERR_OM | Out of memory. |
Notes
- All registers not shown above are not used on entry and are preserved on exit.
- The space allocated contains in its first long word the size of the space. Provided the user has a copy of this size the whole of the space can be used.
Example
The example below shows how to obtain space from a user heap.
It is assumed that A6 points to the data space and that the address of the pointer to free space is in heapad(a6). See MM_LNKFR/MEM_REHP.
move.l #504,d1 ; Number of bytes needed
lea heapad(a6),a0 ; Pointer to pointer to free space
movea.w MM_ALLOC,a2 ; address of MM_ALLOC
jsr (a2) ; Make the call
bne.s Error_handler ; Oops!
qdosmsq/vectors/alhp.txt · Last modified: 2009/02/12 14:46 by george.gwilt
