Linux 中的key code and scan code

我們知道i8042會將keyboard 送過來的scan code(不管是屬於set2 or set3)轉換成set 1,而linux再keyboard driver(drivers/input/keyboard/atkbd.c)中會將該scan code轉換成對應的key code 或是i8042沒有進行set 1的轉換則 keyboard driver會依據keyboard支援set轉換成對應的key code，該程式碼片斷如下所示：


static const unsigned short atkbd_unxlate_table[128] = {
0,118, 22, 30, 38, 37, 46, 54, 61, 62, 70, 69, 78, 85,102, 13,
21, 29, 36, 45, 44, 53, 60, 67, 68, 77, 84, 91, 90, 20, 28, 27,
35, 43, 52, 51, 59, 66, 75, 76, 82, 14, 18, 93, 26, 34, 33, 42,
50, 49, 58, 65, 73, 74, 89,124, 17, 41, 88, 5, 6, 4, 12, 3,
11, 2, 10, 1, 9,119,126,108,117,125,123,107,115,116,121,105,
114,122,112,113,127, 96, 97,120, 7, 15, 23, 31, 39, 47, 55, 63,
71, 79, 86, 94, 8, 16, 24, 32, 40, 48, 56, 64, 72, 80, 87,111,
19, 25, 57, 81, 83, 92, 95, 98, 99,100,101,103,104,106,109,110
};
static unsigned char atkbd_set2_keycode[512] = {
0, 67, 65, 63, 61, 59, 60, 88, 0, 68, 66, 64, 62, 15, 41,117,
0, 56, 42, 93, 29, 16, 2, 0, 0, 0, 44, 31, 30, 17, 3, 0,
0, 46, 45, 32, 18, 5, 4, 95, 0, 57, 47, 33, 20, 19, 6,183,
0, 49, 48, 35, 34, 21, 7,184, 0, 0, 50, 36, 22, 8, 9,185,
0, 51, 37, 23, 24, 11, 10, 0, 0, 52, 53, 38, 39, 25, 12, 0,
0, 89, 40, 0, 26, 13, 0, 0, 58, 54, 28, 27, 0, 43, 0, 85,
0, 86, 91, 90, 92, 0, 14, 94, 0, 79,124, 75, 71,121, 0, 0,
82, 83, 80, 76, 77, 72, 1, 69, 87, 78, 81, 74, 55, 73, 70, 99,

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
217,100,255, 0, 97,165, 0, 0,156, 0, 0, 0, 0, 0, 0,125,
173,114, 0,113, 0, 0, 0,126,128, 0, 0,140, 0, 0, 0,127,
159, 0,115, 0,164, 0, 0,116,158, 0,150,166, 0, 0, 0,142,
157, 0, 0, 0, 0, 0, 0, 0,155, 0, 98, 0, 0,163, 0, 0,
226, 0, 0, 0, 0, 0, 0, 0, 0,255, 96, 0, 0, 0,143, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0,107, 0,105,102, 0, 0,112,
110,111,108,112,106,103, 0,119, 0,118,109, 0, 99,104,119, 0,

0, 0, 0, 65, 99,

};

static unsigned char atkbd_set3_keycode[512] = {

0, 0, 0, 0, 0, 0, 0, 59, 1,138,128,129,130, 15, 41, 60,
131, 29, 42, 86, 58, 16, 2, 61,133, 56, 44, 31, 30, 17, 3, 62,
134, 46, 45, 32, 18, 5, 4, 63,135, 57, 47, 33, 20, 19, 6, 64,
136, 49, 48, 35, 34, 21, 7, 65,137,100, 50, 36, 22, 8, 9, 66,
125, 51, 37, 23, 24, 11, 10, 67,126, 52, 53, 38, 39, 25, 12, 68,
113,114, 40, 43, 26, 13, 87, 99, 97, 54, 28, 27, 43, 43, 88, 70,
108,105,119,103,111,107, 14,110, 0, 79,106, 75, 71,109,102,104,
82, 83, 80, 76, 77, 72, 69, 98, 0, 96, 81, 0, 78, 73, 55,183,

184,185,186,187, 74, 94, 92, 93, 0, 0, 0,125,126,127,112, 0,
0,139,150,163,165,115,152,150,166,140,160,154,113,114,167,168,
148,149,147,140
};

/*
* atkbd_set_keycode_table() initializes keyboard's keycode table
* according to the selected scancode set
*/

static void atkbd_set_keycode_table(struct atkbd *atkbd)
{
int i, j;

memset(atkbd->keycode, 0, sizeof(atkbd->keycode));

if (atkbd->translated) {
//這裡執行的就是一般接到i8042所傳過來的set1 scancode的key code轉換
for (i = 0; i <>keycode[i] = atkbd_set2_keycode[atkbd_unxlate_table[i]];
atkbd->keycode[i | 0x80] = atkbd_set2_keycode[atkbd_unxlate_table[i] | 0x80];
if (atkbd->scroll)
for (j = 0; j <>keycode[i | 0x80] = atkbd_scroll_keys[j].keycode;
}
} else if (atkbd->set == 3) {
memcpy(atkbd->keycode, atkbd_set3_keycode, sizeof(atkbd->keycode));
} else {
memcpy(atkbd->keycode, atkbd_set2_keycode, sizeof(atkbd->keycode));

if (atkbd->scroll)
for (i = 0; i <>keycode[atkbd_scroll_keys[i].set2] = atkbd_scroll_keys[i].keycode;
}

atkbd->keycode[atkbd_compat_scancode(atkbd, ATKBD_RET_HANGEUL)] = KEY_HANGUEL;
atkbd->keycode[atkbd_compat_scancode(atkbd, ATKBD_RET_HANJA)] = KEY_HANJA;
}


-------------------------------------------------------------------------------
//由該程式可以證明上述所言不假

#include <&stdio.h&>


static const unsigned short atkbd_unxlate_table[128] = {
0,118, 22, 30, 38, 37, 46, 54, 61, 62, 70, 69, 78, 85,102, 13,
21, 29, 36, 45, 44, 53, 60, 67, 68, 77, 84, 91, 90, 20, 28, 27,
35, 43, 52, 51, 59, 66, 75, 76, 82, 14, 18, 93, 26, 34, 33, 42,
50, 49, 58, 65, 73, 74, 89,124, 17, 41, 88, 5, 6, 4, 12, 3,
11, 2, 10, 1, 9,119,126,108,117,125,123,107,115,116,121,105,
114,122,112,113,127, 96, 97,120, 7, 15, 23, 31, 39, 47, 55, 63,
71, 79, 86, 94, 8, 16, 24, 32, 40, 48, 56, 64, 72, 80, 87,111,
19, 25, 57, 81, 83, 92, 95, 98, 99,100,101,103,104,106,109,110
};
static unsigned char atkbd_set2_keycode[512] = {
0, 67, 65, 63, 61, 59, 60, 88, 0, 68, 66, 64, 62, 15, 41,117,
0, 56, 42, 93, 29, 16, 2, 0, 0, 0, 44, 31, 30, 17, 3, 0,
0, 46, 45, 32, 18, 5, 4, 95, 0, 57, 47, 33, 20, 19, 6,183,
0, 49, 48, 35, 34, 21, 7,184, 0, 0, 50, 36, 22, 8, 9,185,
0, 51, 37, 23, 24, 11, 10, 0, 0, 52, 53, 38, 39, 25, 12, 0,
0, 89, 40, 0, 26, 13, 0, 0, 58, 54, 28, 27, 0, 43, 0, 85,
0, 86, 91, 90, 92, 0, 14, 94, 0, 79,124, 75, 71,121, 0, 0,
82, 83, 80, 76, 77, 72, 1, 69, 87, 78, 81, 74, 55, 73, 70, 99,

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
217,100,255, 0, 97,165, 0, 0,156, 0, 0, 0, 0, 0, 0,125,
173,114, 0,113, 0, 0, 0,126,128, 0, 0,140, 0, 0, 0,127,
159, 0,115, 0,164, 0, 0,116,158, 0,150,166, 0, 0, 0,142,
157, 0, 0, 0, 0, 0, 0, 0,155, 0, 98, 0, 0,163, 0, 0,
226, 0, 0, 0, 0, 0, 0, 0, 0,255, 96, 0, 0, 0,143, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0,107, 0,105,102, 0, 0,112,
110,111,108,112,106,103, 0,119, 0,118,109, 0, 99,104,119, 0,

0, 0, 0, 65, 99,

};
unsigned char keycode[512];
void fuc();
int main(){
fuc();
//include/linux/input.h定義KEY_F1為59(0x3b)
printf("%d\n",keycode[0x3B]);//output is 59
printf("%d\n",atkbd_set2_keycode[0x05]);//output is 59

}

void fuc(){
int i,scancode;
for (i = 0; i < 128; i++) {
scancode = atkbd_unxlate_table[i];
keycode[i] = atkbd_set2_keycode[scancode];
keycode[i | 0x80] = atkbd_set2_keycode[scancode | 0x80];
}
}