/* * This file was a very early example, written by consulting [1]. It was * useful primarily to see how the GNU assembler handles these opcodes, to * better understand the encoding. * * [1] https://www.muppetlabs.com/~breadbox/software/tiny/teensy.html * * * gcc -o exit-code -nostartfiles -nostdlib exit-code.gnu.asm && ./exit-code ; echo $? * * or * * as -o exit-code.o exit-code.gnu.asm && ld -s -o exit-code exit-code.o && ./exit-code; echo $? * * Can't use nasm, nasm is 32-bit only. * * Since you get a nice clean file, you can then do: * * objdump --disassemble exit-code */ .text .global _start _start: mov $60, %eax mov $42, %edi syscall