port.c

来自「国内的一个小型操作系统」· C语言 代码 · 共 20 行

inline void outportb(unsigned int port, unsigned char value)  // Output a byte to a port
{
    asm volatile("outb %%al,%%dx"::"d"(port), "a"(value));
};

inline void outportw(unsigned int port,unsigned int value)  // Output a word to a port
{
    asm volatile("outw %%ax,%%dx"::"d"(port), "a"(value));
};

inline unsigned char inportb(unsigned short port)
{
    unsigned char ret_val;

    asm volatile("inb %1,%0"
                :"=a"(ret_val)
                :"d"(port));
    return ret_val;
};