avr: added Heap_AllocAndZero

avr/modules/heap/main.asm

@@ -86,6 +86,39 @@ Heap_Alloc:
 
 
 
+; ---------------------------------------------------------------------------
+; @routine Heap_AllocAndZero
+;
+; Allocates data on the heap and presets all bytes with zero.
+;
+; @param r25:r24 number of bytes to alloc
+; @return CFLAG set of okay, cleared otherwise
+; @return X start of allocated memory
+; @clobbers r16, r17, r18, r19, r24, r25, X
+
+Heap_AllocAndZero:
+  push r24
+    push r25
+      rcall heapAllocFirstFit
+    pop r25
+  pop r24
+  brcc Heap_AllocAndZero_ret
+  push xl
+    push xh
+      clr r18
+Heap_AllocAndZero_loop:
+        st X+, r18
+        sbiw r25:r24, 1
+      brne Heap_AllocAndZero_loop
+    pop xh
+  pop xl
+  sec
+Heap_AllocAndZero_ret:
+  ret
+; @end
+
+
+
 
 ; ---------------------------------------------------------------------------
 ; @routine heapAllocFirstFit