minux的源代码,一个非常小的操作系统

				#include 
				#define waitpid	_waitpid
				#include 
				
				PUBLIC pid_t waitpid(pid, status, options)
				pid_t pid;
				int *status;
				int options;
				{
				  message m;
				
				  m.m1_i1 = pid;
				  m.m1_i2 = options;
				  if (_syscall(MM, WAITPID, &m) < 0) return(-1);
				  if (status != 0) *status = m.m2_i1;
				  return m.m_type;
				}