Here's the entire assembly program:
.model small .stack 256 .code start: call printer mov ax, 3 ; store 3 into ax mov ah, 76 ; back to DOS mov al, 0 ; no errors int 21h ; interupt -> DOS end start And this is where I define the C function printer
#include <stdio.h> void printer() { printf("Hello!\n"); } When compiling the assembly code, I get an error: undefined symbol: printer. In C I would do an #include "file.h", how do I achieve the same result here?
The problem is not compilation, it's linking. You must link (using ld if on Unix/Linux) your executable including the object file with the assembly code and the object file with the C code.
Or put your assembly code into your C file using an "asm" block.
undefined symbol.You should add something like
extern _printer on the top of your assembly and use call with this name
call _printer Correct name of function depends on naming convention of your C compiler. Compiler may add some characters to the C name of the function.
Correct "extern" keyword depends on your assembler and it could be ".extern" or so.
Edit 1: In Turbo Assembler and for that case with function without parameter, it should be just
extrn printer or
extrn printer:NEAR I am not familiar with TASM.
extern or .extern as a keyword. So I keep getting Illegal instruction. Any other ideas?
EXTRN? stackoverflow.com/questions/14893969/…