Ok so basically I was just writing a C program to build my object files and then create executeables from them by using nasm and ld respectively
The program I wrote makes the correct calls to nasm and ld but I either compile fine with -f win32/win64 ( I'm on a 64 bit windows 7 machine ) or fail with the other options which is fine though... right? If the program compiles and creates the exe it runs and immediately crashes without printing the Hello World message. I'd Really like to jump into assembly. Some Help ?
section .text
global _start ;must be declared for linker (ld)
_start: ;tells linker entry point
mov edx,len ;message length
mov ecx,msg ;message to write
mov ebx,1 ;file descriptor (stdout)
mov eax,4 ;system call number (sys_write)
int 0x80 ;call kernel
mov ah,00
int 16h
mov eax,1 ;system call number (sys_exit)
int 0x80 ;call kernel
section .data
msg db 'Hello, world!', 0xa ;our dear string
len equ $ - msg ;length of our dear string
I also happen to have a kali system ; I don't suppose I could compile for both operating systems without using Wine?
So my C program is working nicely! I can't find any examples of code to assemble though. Well I can... but it all fails. Does anyone have a link?
#include <stdio.h>
#include <stdlib.h>
#include <CustomHeader_Small.h>
void Assemble(void);
void PrintMenu(void);
void LoadOptions(void);
void SaveOptions(void);
char TempBuff[255];
char Format[30];
void SaveOptions(void)
{
FILE *Source = fopen("Settings.ini","w");
if(Source)
{
printf("%s","Enter A Format Type ->");
scanf("%s",Format); //Save Format
fprintf(Source,"Format:%s",Format);
fclose(Source);
puts("Settings Updated!");
LoadOptions();
}
return;
}
void LoadOptions(void)
{
FILE *Source = fopen("Settings.ini","r");
if(Source)
{
char ch;
int i;
char Line[50];
fscanf(Source,"%s",Line);
CCopy(Line,CPos(Line,":",0)+1,CLen(Line),Format,0,1);
free(Line);
}
else
{
Source = fopen("Settings.ini","w");
fprintf(Source,"%s","Format:Win32");
fclose(Source);
}
PrintMenu();
LoadOptions();
return;
}
void PrintMenu(void)
{
printf("%s","Menu:\n________\n1.) [C]reate A New Project.\n2.) [O]pen A Project.\n3.) [A]ssemble A Project.\n4.) [E]dit Settings\n");
printf("%s","5.) [Q]uit\n");
return;
}
void Assemble(void)
{
char *File=malloc(256);
printf("Note : Compiling In %s Mode\n",Format);
printf("%s","Enter A Project Name -> ");
scanf("%s",File);
char *Command;
int ch;
while((ch=getchar())!='S')
{
Command=malloc(1024);
strcpy(Command,"H:\\Users\\Grim\\AppData\\Local\\nasm\\nasm.exe -f ");
strcat(Command,Format);
strcat(Command," ");
strcat(Command,File);
strcat(Command,"\\");
strcat(Command,File);
strcat(Command,".asm ");
strcat(Command,"-o ");
strcat(Command,File);
strcat(Command,"\\");
strcat(Command,File);//This Creates The Object File Using Nasm ( Not Just Yet But Were Well On Our Way!
strcat(Command,".o");
system(Command); //Calls Nasm.
free(Command);
Command=malloc(1024);
strcpy(Command,"H:\\MinGW\\bin\\ld.exe ");
strcat(Command,File);
strcat(Command,"\\");
strcat(Command,File);
strcat(Command,".o ");
strcat(Command,"-o ");
strcat(Command,File);//This Creates The Executable File Using Nasm ( Not Just Yet But Were Well On Our Way!
strcat(Command,"\\");
strcat(Command,File);
strcat(Command,".exe");
system(Command); //Calls Nasm.
free(Command);
puts("Press Enter To Compile Again But Enter An [S] Followed By Enter To [S]top.");
}
free(File);
puts("NasmWrapper Assembly Done!");
printf("%s","\n\n\n");
PrintMenu();
return;
}
int main()
{
LoadOptions();
char ch;
while((ch = getchar())!='Q')
{
if(ch=='A') Assemble();
if(ch=='E') SaveOptions();
}
return 0;
}
Also any comments on the C program would be nice :D Thanks for explaining how to use the [Code] thing.
