Question

I have a assembly file and a c file compiled to .o files (start.o and main.o) and is trying to link them with ld. I’m using this command:

ld -T link.ld -o kernel.bin start.o main.o 

where link.ld is a linker script, but when I run it, i get this error:

start.o:start.o:(.text+0x2d): undefined reference to `_main' 

in the assembly file, I call the c file with this function:

stublet: extern _main call _main  jmp $ 

Anybody can see what’s wrong?

Answer 1

Some compilers (like GCC for Linux) don’t add _ by default to C library exports. Try nm main.o to see the actual reference name. It might be main rather than _main.