I have a 64 bit VM setup with Linux Mint, I'm trying to use a 32 bit program on this machine. This program has 3 parts.
- library.asm
- main.asm
- p2-main.c
I run these commands and 1 & 2 parts work together with expected results when I run Main.
nasm -f elf32 library.asm
nasm -f elf32 main.asm
gcc -m32 main.o library.o -o Main
Then I use this and run into issues with parts 1 & 3:
gcc -m32 p2-main.c library.o -o P2-Main
When I do this the first part of my .c program works, but when trying to pull the results from the original library I get a "Segmentation fault (core dumped)" error.
Am I doing something wrong with the commands?
Would I have to change something with the .c program to work on 64 bit?
I have confirmed with someone that has a 32 bit VM with Linux Mint that the code works. Any suggestions?
Here is my code for the 3 parts
library:
SECTION .DATA
Pint: db ' %d',0
Spaces: db ' ',0
num: db 'Number',0
total: db ' Runninig total',10,0
newline: db '',10,0
SECTION .text
global _sumAndPrintList ;printf use global main
global _replaceChar
extern printf
_replaceChar:
mov eax,0
mov edx,0
mov edx,[esp+16]
mov eax,[esp+12]
mov edi,[esp+4]
mov ecx,[esp+8]
;jmp exit
while:
mov bl,[edi]
cmp bl,al
jne skip
mov [edi],dl
skip:
inc edi
loop while
exit:
ret
_sumAndPrintList:
push num
call printf
add esp,4
push total
call printf
add esp,4
mov esi,[esp+8]
mov edi,[esp+4]
mov ebx,0
while1:
cmp esi,0
jle break
mov eax,[edi]
add ebx,eax
push eax
push Pint
call printf
add esp,8
push Spaces
call printf
add esp,4
push ebx
push Pint
call printf
add esp,8
push newline
call printf
add esp,4
add esi,-1
add edi,4
jmp while1
break:
mov eax,ebx
ret ; Return control
Main:
global main ;printf use global main
extern _replaceChar
extern printf
Section .data
Pint: db '%d',10,0
stat1: db 'Enter a character to Serach for:',10,0
stat2: db 'Enter a character to replace for:',10,0
stat3: db 'Enter lines of text:',10,0
section .bss
buffer resb 100 ;100B buffer
repChar resb 2
searchChar resb 2
SECTION .text
push stat1
call printf
add esp,4
mov eax, 3 ; 'read' system call = 3
mov ebx, 0 ; file descriptor 0 = STDOUT
mov ecx, searchChar ;adress of buffer to store input
mov edx, 2 ;max number of bytes to read
int 80h
push stat2
call printf
add esp,4
mov eax, 3 ; 'read' system call = 3
mov ebx, 0 ; file descriptor 0 = STDOUT
mov ecx, repChar ;adress of buffer to store input
mov edx, 2 ;max number of bytes to read
int 80h
push stat3
call printf
add esp,4
mov eax, 3 ; 'read' system call = 3
mov ebx, 0 ; file descriptor 0 = STDOUT
mov ecx, buffer ;adress of buffer to store input
mov edx, 100 ;max number of bytes to read
int 80h
mov ecx,0
mov edx,0
mov eax,buffer
mov ebx,100
mov esi,repChar
mov edi,searchChar
mov cl,[edi]
mov dl,[esi]
push edx
push ecx
push ebx
push eax
call _replaceChar
add esp,16
mov eax,4 ; 'write' system call = 4
mov ebx,1 ; file descriptor 1 = STDOUT
mov ecx,buffer ; string to write
mov edx,100 ; length of string to write
int 80h
exit:
;Terminate program
mov eax, 0x1
xor ebx, ebx
int 0x80
p2-main.c
/* example.c */
#include <stdio.h>
#include <string.h>
int _sumAndPrintList(int *list,int a);
int _replaceChar(char *text,int len,char ser,char rep);
int main(int argc, char *argv[]) {
char s[]="Hello";
int a=1;
int list[1000];
printf("This list will end on negative number input!\n");
int i=0;
while(a>0)
{
scanf("%d", &list[i]);
getchar();
a=list[i];
i++;
}
int len=i-1;
int b=_sumAndPrintList(list,len);
printf("The function returned a sum of %d, does that match the last number in the running total column?\n",b);
printf("------------------------------------------------------------\n");
printf("Enter Lines of text:\n");
char text[100];
len=strlen(text);
char serachChar=' ';
char replaceChar='_';
fgets(text,sizeof(text),stdin);
_replaceChar(text,100,serachChar,replaceChar);
printf("%s\n",text);
return 0;
}
