#define SYS_halt 0 /* Halts the operating system. */
#define SYS_exit 1 /* Terminates this process. */
#define SYS_exec 2 /* Start another process. */
#define SYS_halt 0 /* Halts the operating system. */
#define SYS_exit 1 /* Terminates this process. */
#define SYS_exec 2 /* Start another process. */