NASM - The Netwide Assembler

NASM Forum => Programming with NASM => Topic started by: rostomdz on May 28, 2011, 10:18:57 AM

Title: Problem with linking obj files !!
Post by: rostomdz on May 28, 2011, 10:18:57 AM

good morning every one  :D

i'm trying to write a simple kernel using gcc 64bit for C and C++, and nasm for assembly.
well, i tried to compile a simple code for the kernel , but the problem is in linking!!!!
when i link the objs files the linker tells me that the (nasm) object file format doesn't recognized :


C:\nasm\Nouveaudossier>gcc -c video.cpp -ffreestanding -nostdlib -fno-builtin -fno-rtti -fno-exceptions -o Video.obj

C:\nasm\Nouveaudossier>gcc -c kernel.cpp -ffreestanding -nostdlib -fno-builtin -fno-rtti -fno-exceptions -o Kernel.obj

C:\nasm\Nouveaudossier>nasm -f aout k_init.asm -o k_init.obj

C:\nasm\Nouveaudossier>ld -T Link.ld -o KRNL.BIN Kernel.obj Video.obj K_init.obj
K_init.obj: file not recognized: File format not recognized

C:\nasm\Nouveaudossier>pause
Appuyez sur une touche pour continuer...

K_init.obj: file not recognized: File format not recognized     :-X

i think the problem is that nasm that i use is 32bit and the linker and gcc compiler is 64bit, so form where can i download the nasm 64bit , help me please.

sorry for my English  ;D .     

Title: Re: Problem with linking obj files !!
Post by: Keith Kanios on May 28, 2011, 10:43:54 AM

Quote from: rostomdz on May 28, 2011, 10:18:57 AM

when i link the objs files the linker tells me that the (nasm) object file format doesn't recognized

Try ELF (-f elf64) instead.

Title: Re: Problem with linking obj files !!
Post by: rostomdz on May 28, 2011, 11:14:08 AM

thnx brother it's work  :D
the linker still doesn't work but when i invoke it form gcc, it work clearly without using the link script. i like this awesome forum. ::)


C:\nasm\Nouveaudossier>gcc -c video.cpp -ffreestanding -nostdlib -fno-builtin -fno-rtti -fno-exceptions -o Video.obj

C:\nasm\Nouveaudossier>gcc -c kernel.cpp -ffreestanding -nostdlib -fno-builtin -fno-rtti -fno-exceptions -o Kernel.obj

C:\nasm\Nouveaudossier>nasm -f elf64 k_init.asm -o k_init.obj

C:\nasm\Nouveaudossier>ld -T Link.ld -o KRNL.BIN Kernel.obj Video.obj K_init.obj
ld: cannot perform PE operations on non PE output file 'KRNL.BIN'.

C:\nasm\Nouveaudossier>gcc -o KENL.EXE Kernel.obj Video.obj K_init.obj
coooool that Done  :) :)  
C:\nasm\Nouveaudossier>pause
Appuyez sur une touche pour continuer...

Title: Re: Problem with linking obj files !!
Post by: Frank Kotler on May 28, 2011, 01:47:38 PM

The references to ".exe" and "PE operations" make me think you may want "-f win64" instead of "-f elf64". Just guessing, but try that.

Best,
Frank

Title: Re: Problem with linking obj files !!
Post by: Rob Neff on May 28, 2011, 03:33:42 PM

You mention previously that you are building a kernel.  You are doing this on a Windows machine, apparently using a MingW gcc, with nasm.  You are outputting a Windows executable ( .exe ).
You do realize that you will not be able to issue kernel-type operations unless you are running within a VM where you have also written the loader.
Finally, if the machine you are building on, and the tools you are using, are 64-bit, but you need 32-bits - try adding the command line option -m32 to gcc.
This may, or may not, help you.