Initial import.

avr/utils.asm

@@ -0,0 +1,51 @@
+
+
+
+; ***************************************************************************
+; Utils_FillSram
+;
+; IN:
+; - x: pointer to SRAM to fill
+; - r16: value to fill the SRAM with
+; - r17: size of area to fill
+; OUT:
+; - nothing
+; MODIFIED REGISTERS: r17, x
+
+Utils_FillSram:
+  tst r17
+  breq Utils_FillSram_end
+
+Utils_FillSram_loop:
+    st x+, r16
+    dec r17
+  brne Utils_FillSram_loop
+Utils_FillSram_end:
+  ret
+
+
+
+; ***************************************************************************
+; Increment a 32 bit counter at the address given by X.
+; IN:
+; - X: Address of the 4 byte counter (1. byte is LSB)
+; OUT:
+; - nothing
+; MODIFIED REGISTERS: r18, r19, r20, r21, 22
+
+Utils_IncrementCounter32:
+  ld r18, x+
+  ld r19, x+
+  ld r20, x+
+  ld r21, x
+  clr r22
+  inc r18
+  adc r19, r22
+  adc r20, r22
+  adc r21, r22
+  st x, r21
+  st -x, r20
+  st -x, r19
+  st -x, r18
+  ret
+