I am working on x86 assembly language. I want to get two parameters that one is column and other one is row, using randomrange within the interval [0,5]. Here I tried to adjust the interval by dividing the random number by 6, and getting the number remains in DL which is remainder of the division.
I also implemented an array that holds the numbers that randomized before and jumps back to randomization if the element is already 1, which uses row*6+col to check the index, but this array is not effective yet.
I get a segmentation fault, what could be the problem?
TITLE Program Template (template.asm)
INCLUDE Irvine32.inc
INCLUDE macros.inc
.data
onezero BYTE 36 DUP(0)
row BYTE 0
col BYTE 0
.code
main PROC
_again:
call randomrange
mov bx, 6
div bx
mov row, dl
call randomrange
div bx
mov col, dl
movzx eax, row
mov ebx, 6
mul ebx
movzx ecx, col
add eax, ecx
mov edi, eax
mov al, 1
cmp al, onezero[edi]
je _again
movzx eax, row
call writeint
movzx eax, col
call writeint
main ENDP
END main
The irvine RandomRange function already has this functionality:
; Returns an unsigned pseudo-random 32-bit integer
; in EAX, between 0 and n-1. Input parameter:
; EAX = n.
Also note that div bx is dividing the 32 bit number formed from dx:ax and not eax.
As for the segfault, use a debugger and see where the crash is.