U-Boot Command 架構

Ex:

int setGpioA(u32 pin, u32 value);
int unknown_GPIO(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]) //argc 參數個數
{
   
    if((strcmp(argv[1], "on") == 0) || (strcmp(argv[1], "ON") == 0))
    {
         setGpioA(10, 0);
    }
    else if((strcmp(argv[1], "off") == 0) || (strcmp(argv[1], "OFF") == 0))
    {
         setGpioA(10, 1);
    }
    return 0;
}

int setGpioA(u32 pin, u32 value)
{
    volatile unsigned int reg = 0x01 << pin;
    if(value == 1)
    {
        *((volatile unsigned int *)0x74000000) |= reg;  //取暫存器位址之值
        printf("ndlndsnlk 0x74000000 %X\n" , reg);
       
    }
    else
    {
        *((volatile unsigned int *)0x74000000) &= ~reg;
    }
    return 0;
}
   
U_BOOT_CMD(
        unknown,      2,     4,      unknown_GPIO,
        "Unknown GPIO \n",
        ""
        "input on/off \n"
);