这两行代码非常重要,其实能把这些理解了也就和51没啥差别了,个人愚见<br />//打开内存空间<br />if((fd = open("/dev/mem", O_RDWR | O_SYNC)) == -1){<br /> DEBUGMSG(DEBUG_ERR, "gpio: Error opening /dev/mem
");<br /> exit(-1);<br /> }<br /> //map 0xffff<br />//获得AT91_SYS的虚拟地址<br />map_base = mmap(0, MAP_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, fd, AT91_SYS);//AT91_SYS = 0xffff f000
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