lab1：kern/console.c：键盘码映射

        'B', 'N', 'M', '<', '>', '?', NO, '*', // 0x30

        NO, ' ', NO, NO, NO, NO, NO, NO,
        NO, NO, NO, NO, NO, NO, NO, '7', // 0x40

        '8', '9', '-', '4', '5', '6', '+', '1',
        '2', '3', '0', '.', NO, NO, NO, NO, // 0x50

        [0xC7] KEY_HOME, [0x9C] '\n' /*KP_Enter*/,
        [0xB5] '/' /*KP_Div*/, [0xC8] KEY_UP,
        [0xC9] KEY_PGUP, [0xCB] KEY_LF,
        [0xCD] KEY_RT, [0xCF] KEY_END,
        [0xD0] KEY_DN, [0xD1] KEY_PGDN,
        [0xD2] KEY_INS, [0xD3] KEY_DEL
};

#define C(x) (x - '@')

static uint8_t ctlmap[256] =
{
        NO, NO, NO, NO, NO, NO, NO, NO,
        NO, NO, NO, NO, NO, NO, NO, NO,
        C('Q'), C('W'), C('E'), C('R'), C('T'), C('Y'), C('U'), C('I'),
        C('O'), C('P'), NO, NO, '\r', NO, C('A'), C('S'),
        C('D'), C('F'), C('G'), C('H'), C('J'), C('K'), C('L'), NO,
        NO, NO, NO, C('\\'), C('Z'), C('X'), C('C'), C('V'),
        C('B'), C('N'), C('M'), NO, NO, C('/'), NO, NO,
        [0x97] KEY_HOME,
        [0xB5] C('/'), [0xC8] KEY_UP,
        [0xC9] KEY_PGUP, [0xCB] KEY_LF,
        [0xCD] KEY_RT, [0xCF] KEY_END,
        [0xD0] KEY_DN, [0xD1] KEY_PGDN,
        [0xD2] KEY_INS, [0xD3] KEY_DEL
};

static uint8_t *charcode[4] = {
        normalmap,
        shiftmap,
        ctlmap,
        ctlmap
};