brk.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

/* consider this code LGPL - davidm */

#include <unistd.h>
#include <sys/syscall.h>
#include <errno.h>

/* This must be initialized data because commons can't have aliases.  */
void * ___brk_addr = 0;

int brk (void *addr)
{
    void *newbrk;

	__asm__ volatile ("movel %2,%/d1\n\t"
			  "moveq %1,%/d0\n\t"
			  "trap  #0\n\t"
			  "movel %/d0,%0"
		:"=g" (newbrk)
		:"i" (__NR_brk),"g" (addr) : "%d0", "%d1");

    ___brk_addr = newbrk;

    if (newbrk < addr)
    {
	__set_errno (ENOMEM);
	return -1;
    }

    return 0;
}