fork.c

它通过提供glibc兼容使得应用程序移植到较小的c 库时相当得容易. 它能够应用到带虚拟存储的Linux和uClinux上.在大多数带MMU部件的平台上为使它更加紧凑,它也能够编译成共享库.uClib

#include <sysdep.h>

SYSCALL__ (fork, 0)
	/* R1 is now 0 for the parent and 1 for the child.  Decrement it to
	   make it -1 (all bits set) for the parent, and 0 (no bits set)
	   for the child.  Then AND it with R0, so the parent gets
	   R0&-1==R0, and the child gets R0&0==0.  */
     /* i dunno what the blurb above is useful for. we just return. */
__asm__("ret\n\tnop");