New to Assembly language, reading a book here. I'm trying to do an simple basic exercise. Using appropriate registers, I have to add 100, 200, 300, 400, 500. Don't know where to start with this program. This is the outline of the program, now I need to add the registers. This is what I have, from what I understand from the book. Don't know how to keep adding.
(AddSub.asm)
INCLUDE Irvine32.inc
.code
main PROC
mov eax, 100
add eax, 200
exit
main ENDP
END main
Answer
If you have experience with higher level languages like C, then these lines:
mov eax, 100
add eax, 200
Would do something akin to:
int eax;
eax = 100; /* mov 100 to EAX */
eax = eax + 200; /* add 200 to EAX */
If you want to add other numbers you keep adding to EAX like:
add eax, 300
add eax, 400
You can use other registers besides EAX (like EBX,ECX,EDX,ESI,EDI). You can also add these registers together. For example
mov eax, 100
mov ebx, 200
mov ecx, 300
add eax, ebx
add eax, ecx
This would be akin to:
int eax = 100;
int ebx = 200;
int ecx = 300;
eax = eax + ebx; /* add EBX to EAX */
eax = eax + ecx; /* add ECX to EAX */
Which would result in a value of 600 in EAX
Using Irvine32 library you can print the contents of EAX as a signed integer by calling the WriteInt function like so:
call WriteInt