src/linux-start.s

.section .text
.globl _start
.type _start, @function
_start:
	xorq %rbp, %rbp # frame ptr (%rbp) = null. marks stack bottom.
 
	movq (%rsp), %rdi # argc = first 4 bytes of stack.
	leaq 8(%rsp), %rsi # argv = address of first arg ptr.
 
	call main
 
	movl %eax, %edi # status = ret val.
	movl $60, %eax # SYS_exit = 60.
	syscall
 
	hlt # if syscall fails hang.