AREA calculator, CODE, READONLY ; assembly header

compute_asm
          IMPORT OPERAND_1 ; imports from C file
          IMPORT OPERAND_2 ; imports from C file
          IMPORT USER_OPERATION ; imports from C file
          ALIGN ; aligns memory

initial_values PROC
          LDR R1, =OPERAND_1; loads R1 with OPERAND_1
          LDR R2, =OPERAND_2; loads R2 with OPERAND_2

int OPERAND_1; //declares OPERAND_1 for Assembly use
int OPERAND_2; //declares OPERAND_2 for Assembly use
int USER_OPERATION; //declares USER_OPERATION for Assembly use

extern int add_number(); //links add_number function in Assembly
extern int subtract_number(); //links subtract_number function in Assembly