/* Write an assembly function that performs the sum of four constants 10, 20, 30 and 40, and returns the result.
Function name:
int my_asm_add_four_constants(void) */
#include <stdio.h>
#include <stdlib.h>

void myPrint(char * fnName, unsigned int result);
extern "C"{
  unsigned int my_asm_add_four_constants(void);
}
void setup() {
  // put your setup code here, to run once:
  Serial1.begin(9600);
  pinMode(LED_BUILTIN,OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  unsigned int asm_ret_val;
  asm_ret_val = my_asm_add_four_constants();
  myPrint("my_asm_add_four_constants()",asm_ret_val);
  digitalWrite(LED_BUILTIN,HIGH);
  delay(1000);
  digitalWrite(LED_BUILTIN,LOW);
  delay(1000);
}

void myPrint(char * fnName, unsigned int result)
{
  Serial1.print("The value returned from the assembly fn ");
  Serial1.print(fnName);
  Serial1.print(" : ");
  Serial1.println(result);
}
/* NOTE : ONLY THE VALUE IN R0 GETS RETURNED --> EITHER MOVE THE VALUE TO R0. */