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--- qdosmsq:vectors:rchp [2008/06/27 20:26]
norman created
+++ qdosmsq:vectors:rchp [2008/06/27 20:29] (current)
norman Fixed bugs in three lines of code!
@@ Line 1: / Line 1: @@
+====== MM_RECHP/MEM_RCHP - Vector $C2 ======
+This vector deallocates memory on the common heap. It should only be called in supervisor mode. The vector is atomic. The memory being deallocated should have been allocated using [[qdosmsq:vectors:achp|MM_ALCHP/MEM_ACHP]].
+^Call Parameters^^Return Parameters^^
+|D1.L|Unused. |D1.L|Corrupted.|
+|D2.L|Unused. |D2.L|Corrupted.|
+|D3.L|Unused. |D3.L|Corrupted.|
+|A0.L|Address of area to deallocate. |A0.L|Corrupted.|
+|A1.L|Unused. |A1.L|Corrupted.|
+|A2.L|Unused. |A2.L|Corrupted.|
+|A3.L|Unused. |A3.L|Corrupted.|
+|A6.L|System variables address |A6.L|Preserved.|
+===== Errors =====
+No errors are returned by this vector call.
+===== Notes =====
+  * All registers not shown above are not used on entry and are preserved on exit.
+  * **Must** be called in supervisor mode only.
+  * Mainly used in device driver 'close' routines to deallocate space used for channel definition blocks and so on.
+  * This vector call is //atomic//.
+===== Example =====
+The example below shows the use of this vector to deallocate a previously allocated chunk of memory. For the sake of the example, the start address of the area is assumed to be on the top of the stack.
+<code>
+Kill_hp move.w  MM_RECHP,A2     ; MM_RECHP vector address.
+        movea.l (a7)+,a0        ; Unstack the start of the allocated area.
+                                ; Assume A6 is correct already.
+        jsr      (a2)           ; Make the call.
+        ...                     ; Carry on here.
+</code>