Date: Tue, 30 Aug 2005 13:37:02 +0300 From: Giorgos Keramidas <keramida@ceid.upatras.gr> To: Jonathon McKitrick <jcm@FreeBSD-uk.eu.org> Cc: freebsd-questions@freebsd.org Subject: Re: Linking standalone NASM binary with libc Message-ID: <20050830103702.GA80388@orion.daedalusnetworks.priv> In-Reply-To: <20050830032917.GA39730@dogma.freebsd-uk.eu.org> References: <20050830032917.GA39730@dogma.freebsd-uk.eu.org>
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On 2005-08-30 04:29, Jonathon McKitrick <jcm@FreeBSD-uk.eu.org> wrote:
>
> I'm doing some experimentation with assembly code based on the int80h.org
> tutorials. But since I am going to use malloc and some other functions,
> I need to make my code link with libc rather than stand totally on its own.
>
> ld -s -o foo foo.o -lc
>
> leaves 'environ' and '__progname' undefined. What is the correct way to link
> standalone asm code with needed libraries?
That depends on what the ``standalone'' code contains. If your foo.o
object file defines a 'main' function, then you can just use cc(1):
% tesla:/tmp/foo$ cat -n foo.asm
% 1 global main
% 2 main:
% 3 mov eax,1 ; exit() syscall
% 4 mov ebx,1 ; exit code
% 5 int 0x80 ; trap into kernel
% tesla:/tmp/foo$ nasm -f elf -o foo.o foo.asm
==> % tesla:/tmp/foo$ cc -o foo foo.o
% tesla:/tmp/foo$ ./foo
% tesla:/tmp/foo$ echo $?
% 1
% tesla:/tmp/foo$
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