/*
 * gcc -nostdlib bouzin.c -o bouzin
 */

#define __NR_exit	1
#define __NR_write	4

#define STDOUT_FILENO	1

unsigned int write (int fd, const char *buf, unsigned int len);
void exit (unsigned int code);

int _start (void) {
	char buffer[] = "Hello world !\n", *ptr = buffer;

	while (*++ptr);
	write(STDOUT_FILENO, buffer, ptr - buffer);
	exit(0);
}

unsigned int write (int fd, const char *buf, unsigned int len) {
	unsigned int result;

	__asm__ volatile (
		"int $0x80\n"
		: "=a" (result)
		: "0" (__NR_write),
		  "b" ((long) (fd)),
		  "c" ((long) (buf)),
		  "d" ((long) (len))
		: "memory"
	);
	return result;
}

void exit (unsigned int code) {
	__asm__ volatile ( "int $0x80\n" : : "a" (__NR_exit), "b" ((long) (code)));
}