Apple

hello.s:

.global start

.data

.equ stdout, 1

.equ sys_write, 4
.equ sys_exit, 1

.equ kernel, 0x80

msg: .asciz "Hello World!\n"
.equ len, .-msg

.text

start:
	push $len
	push $msg
	push $stdout
	mov $sys_write, �x
	sub $4, %esp
	int $kernel
	add $4 + $4 * $3, %esp

	push $0
	mov $sys_exit, �x
	sub $4, %esp
	int $kernel

Trace:

$ clang -c -o hello.o hello.s

$ ld -o hello -macosx_version_min 10.6 hello.o

$ ./hello

Bus error: 10

$ gdb hello

(gdb) run

Starting program: /Users/andrew/Desktop/src/mcandre/gas/hello/freebsd/hello

Program received signal EXC_BAD_ACCESS, Could not access memory.

Reason: KERN_PROTECTION_FAILURE at address: 0x0000000000002000

0x0000000000002000 in msg ()

I'm basing my code off of a couple things:

I took the semantics from NASM / Mac OS X and the syntax from Gas / Linux.

I also tried the example program on the GNU Assembler Wikipedia page, but it also bus error's.

I filed a bug report with Apple due to its GNU assembler being horribly out of date (as 1.38). They said to use clang instead, so here I am.

What am I doing wrong?

Specs:

* ld64-134.9

* clang 4.1

* Xcode 4.5

* Mac OS X 10.8.2

* MacBook Pro 2009