上一篇中我们打印的只是扫描码而已,我们想根据扫描码打印出相应的字符,这就需要一个扫描码和相应字符的ASCII码的一个映射,这就需要建一章表。我们先来看看扫描码,Scan Code Set 1:
那么我们怎么把扫描码和相应ASCII对应起来呢,就是建立一张表,用Make Code的值当作数组的下标,相应下标的值就是对应的ASCII码,那么Break Code怎么跟ASCII码对应呢?从上表中看出一个规律,Make Code | 0x80 = Break Code,就可以先把Break Code转换为Make Code,再利用Make Code找到ASCII码。
在include文件夹下建立一个keymap.h文件,我直接copy作者的代码了,写这玩意太费神了:
- /*====================================================================
- keymap.h
- ====================================================================*/
- #ifndef _KEY_MAP_H_
- #define _KEY_MAP_H_
- /* Keymap for US MF-2 keyboard. */
- u32 Key_Map[NR_SCAN_CODES * MAP_COLS] = {
- /* scan-code !Shift Shift E0 XX */
- /* ==================================================================== */
- /* 0x00 - none */ 0, 0, 0,
- /* 0x01 - ESC */ ESC, ESC, 0,
- /* 0x02 - '1' */ '1', '!', 0,
- /* 0x03 - '2' */ '2', '@', 0,
- /* 0x04 - '3' */ '3', '#', 0,
- /* 0x05 - '4' */ '4', '$', 0,
- /* 0x06 - '5' */ '5', '%', 0,
- /* 0x07 - '6' */ '6', '^', 0,
- /* 0x08 - '7' */ '7', '&', 0,
- /* 0x09 - '8' */ '8', '*', 0,
- /* 0x0A - '9' */ '9', '(', 0,
- /* 0x0B - '0' */ '0', ')', 0,
- /* 0x0C - '-' */ '-', '_', 0,
- /* 0x0D - '=' */ '=', '+', 0,
- /* 0x0E - BS */ BACKSPACE, BACKSPACE, 0,
- /* 0x0F - TAB */ TAB, TAB, 0,
- /* 0x10 - 'q' */ 'q', 'Q', 0,
- /* 0x11 - 'w' */ 'w', 'W', 0,
- /* 0x12 - 'e' */ 'e', 'E', 0,
- /* 0x13 - 'r' */ 'r', 'R', 0,
- /* 0x14 - 't' */ 't', 'T', 0,
- /* 0x15 - 'y' */ 'y', 'Y', 0,
- /* 0x16 - 'u' */ 'u', 'U', 0,
- /* 0x17 - 'i' */ 'i', 'I', 0,
- /* 0x18 - 'o' */ 'o', 'O', 0,
- /* 0x19 - 'p' */ 'p', 'P', 0,
- /* 0x1A - '[' */ '[', '{', 0,
- /* 0x1B - ']' */ ']', '}', 0,
- /* 0x1C - CR/LF */ ENTER, ENTER, PAD_ENTER,
- /* 0x1D - l. Ctrl */ CTRL_L, CTRL_L, CTRL_R,
- /* 0x1E - 'a' */ 'a', 'A', 0,
- /* 0x1F - 's' */ 's', 'S', 0,
- /* 0x20 - 'd' */ 'd', 'D', 0,
- /* 0x21 - 'f' */ 'f', 'F', 0,
- /* 0x22 - 'g' */ 'g', 'G', 0,
- /* 0x23 - 'h' */ 'h', 'H', 0,
- /* 0x24 - 'j' */ 'j', 'J', 0,
- /* 0x25 - 'k' */ 'k', 'K', 0,
- /* 0x26 - 'l' */ 'l', 'L', 0,
- /* 0x27 - ';' */ ';', ':', 0,
- /* 0x28 - '/'' */ '/'', '"', 0,
- /* 0x29 - '`' */ '`', '~', 0,
- /* 0x2A - l. SHIFT */ SHIFT_L, SHIFT_L, 0,
- /* 0x2B - '/' */ '//', '|', 0,
- /* 0x2C - 'z' */ 'z', 'Z', 0,
- /* 0x2D - 'x' */ 'x', 'X', 0,
- /* 0x2E - 'c' */ 'c', 'C', 0,
- /* 0x2F - 'v' */ 'v', 'V', 0,
- /* 0x30 - 'b' */ 'b', 'B', 0,
- /* 0x31 - 'n' */ 'n', 'N', 0,
- /* 0x32 - 'm' */ 'm', 'M', 0,
- /* 0x33 - ',' */ ',', '<', 0,
- /* 0x34 - '.' */ '.', '>', 0,
- /* 0x35 - '/' */ '/', '?', PAD_SLASH,
- /* 0x36 - r. SHIFT */ SHIFT_R, SHIFT_R, 0,
- /* 0x37 - '*' */ '*', '*', 0,
- /* 0x38 - ALT */ ALT_L, ALT_L, ALT_R,
- /* 0x39 - ' ' */ ' ', ' ', 0,
- /* 0x3A - CapsLock */ CAPS_LOCK, CAPS_LOCK, 0,
- /* 0x3B - F1 */ F1, F1, 0,
- /* 0x3C - F2 */ F2, F2, 0,
- /* 0x3D - F3 */ F3, F3, 0,
- /* 0x3E - F4 */ F4, F4, 0,
- /* 0x3F - F5 */ F5, F5, 0,
- /* 0x40 - F6 */ F6, F6, 0,
- /* 0x41 - F7 */ F7, F7, 0,
- /* 0x42 - F8 */ F8, F8, 0,
- /* 0x43 - F9 */ F9, F9, 0,
- /* 0x44 - F10 */ F10, F10, 0,
- /* 0x45 - NumLock */ NUM_LOCK, NUM_LOCK, 0,
- /* 0x46 - ScrLock */ SCROLL_LOCK, SCROLL_LOCK, 0,
- /* 0x47 - Home */ PAD_HOME, '7', HOME,
- /* 0x48 - CurUp */ PAD_UP, '8', UP,
- /* 0x49 - PgUp */ PAD_PAGEUP, '9', PAGEUP,
- /* 0x4A - '-' */ PAD_MINUS, '-', 0,
- /* 0x4B - Left */ PAD_LEFT, '4', LEFT,
- /* 0x4C - MID */ PAD_MID, '5', 0,
- /* 0x4D - Right */ PAD_RIGHT, '6', RIGHT,
- /* 0x4E - '+' */ PAD_PLUS, '+', 0,
- /* 0x4F - End */ PAD_END, '1', END,
- /* 0x50 - Down */ PAD_DOWN, '2', DOWN,
- /* 0x51 - PgDown */ PAD_PAGEDOWN, '3', PAGEDOWN,
- /* 0x52 - Insert */ PAD_INS, '0', INSERT,
- /* 0x53 - Delete */ PAD_DOT, '.', DELETE,
- /* 0x54 - Enter */ 0, 0, 0,
- /* 0x55 - ??? */ 0, 0, 0,
- /* 0x56 - ??? */ 0, 0, 0,
- /* 0x57 - F11 */ F11, F11, 0,
- /* 0x58 - F12 */ F12, F12, 0,
- /* 0x59 - ??? */ 0, 0, 0,
- /* 0x5A - ??? */ 0, 0, 0,
- /* 0x5B - ??? */ 0, 0, GUI_L,
- /* 0x5C - ??? */ 0, 0, GUI_R,
- /* 0x5D - ??? */ 0, 0, APPS,
- /* 0x5E - ??? */ 0, 0, 0,
- /* 0x5F - ??? */ 0, 0, 0,
- /* 0x60 - ??? */ 0, 0, 0,
- /* 0x61 - ??? */ 0, 0, 0,
- /* 0x62 - ??? */ 0, 0, 0,
- /* 0x63 - ??? */ 0, 0, 0,
- /* 0x64 - ??? */ 0, 0, 0,
- /* 0x65 - ??? */ 0, 0, 0,
- /* 0x66 - ??? */ 0, 0, 0,
- /* 0x67 - ??? */ 0, 0, 0,
- /* 0x68 - ??? */ 0, 0, 0,
- /* 0x69 - ??? */ 0, 0, 0,
- /* 0x6A - ??? */ 0, 0, 0,
- /* 0x6B - ??? */ 0, 0, 0,
- /* 0x6C - ??? */ 0, 0, 0,
- /* 0x6D - ??? */ 0, 0, 0,
- /* 0x6E - ??? */ 0, 0, 0,
- /* 0x6F - ??? */ 0, 0, 0,
- /* 0x70 - ??? */ 0, 0, 0,
- /* 0x71 - ??? */ 0, 0, 0,
- /* 0x72 - ??? */ 0, 0, 0,
- /* 0x73 - ??? */ 0, 0, 0,
- /* 0x74 - ??? */ 0, 0, 0,
- /* 0x75 - ??? */ 0, 0, 0,
- /* 0x76 - ??? */ 0, 0, 0,
- /* 0x77 - ??? */ 0, 0, 0,
- /* 0x78 - ??? */ 0, 0, 0,
- /* 0x78 - ??? */ 0, 0, 0,
- /* 0x7A - ??? */ 0, 0, 0,
- /* 0x7B - ??? */ 0, 0, 0,
- /* 0x7C - ??? */ 0, 0, 0,
- /* 0x7D - ??? */ 0, 0, 0,
- /* 0x7E - ??? */ 0, 0, 0,
- /* 0x7F - ??? */ 0, 0, 0
- };
- #endif
此数组类似于二维数组,一个扫描码占一行,每一行有三列,分别是单独按某键,Shift+某键,有0xE0前缀的扫描码对应的字符。此头文件中还有许多宏,把它们定义在keyboard.h中,还是复制吧:
- /************************************************************************/
- /* Macros Declaration */
- /************************************************************************/
- #define KB_IN_BYTES 32 /* size of keyboard input buffer */
- #define MAP_COLS 3 /* Number of columns in keymap */
- #define NR_SCAN_CODES 0x80 /* Number of scan codes (rows in keymap) */
- #define FLAG_BREAK 0x0080 /* Break Code */
- #define FLAG_EXT 0x0100 /* Normal function keys */
- #define FLAG_SHIFT_L 0x0200 /* Shift key */
- #define FLAG_SHIFT_R 0x0400 /* Shift key */
- #define FLAG_CTRL_L 0x0800 /* Control key */
- #define FLAG_CTRL_R 0x1000 /* Control key */
- #define FLAG_ALT_L 0x2000 /* Alternate key */
- #define FLAG_ALT_R 0x4000 /* Alternate key */
- #define FLAG_PAD 0x8000 /* keys in num pad */
- #define MASK_RAW 0x01FF /* raw key value = code passed to tty & MASK_RAW
- the value can be found either in the keymap column 0
- or in the list below */
- /* Special keys */
- #define ESC (0x01 + FLAG_EXT) /* Esc */
- #define TAB (0x02 + FLAG_EXT) /* Tab */
- #define ENTER (0x03 + FLAG_EXT) /* Enter */
- #define BACKSPACE (0x04 + FLAG_EXT) /* BackSpace */
- #define GUI_L (0x05 + FLAG_EXT) /* L GUI */
- #define GUI_R (0x06 + FLAG_EXT) /* R GUI */
- #define APPS (0x07 + FLAG_EXT) /* APPS */
- /* Shift, Ctrl, Alt */
- #define SHIFT_L (0x08 + FLAG_EXT) /* L Shift */
- #define SHIFT_R (0x09 + FLAG_EXT) /* R Shift */
- #define CTRL_L (0x0A + FLAG_EXT) /* L Ctrl */
- #define CTRL_R (0x0B + FLAG_EXT) /* R Ctrl */
- #define ALT_L (0x0C + FLAG_EXT) /* L Alt */
- #define ALT_R (0x0D + FLAG_EXT) /* R Alt */
- /* Lock keys */
- #define CAPS_LOCK (0x0E + FLAG_EXT) /* Caps Lock */
- #define NUM_LOCK (0x0F + FLAG_EXT) /* Number Lock */
- #define SCROLL_LOCK (0x10 + FLAG_EXT) /* Scroll Lock */
- /* Function keys */
- #define F1 (0x11 + FLAG_EXT) /* F1 */
- #define F2 (0x12 + FLAG_EXT) /* F2 */
- #define F3 (0x13 + FLAG_EXT) /* F3 */
- #define F4 (0x14 + FLAG_EXT) /* F4 */
- #define F5 (0x15 + FLAG_EXT) /* F5 */
- #define F6 (0x16 + FLAG_EXT) /* F6 */
- #define F7 (0x17 + FLAG_EXT) /* F7 */
- #define F8 (0x18 + FLAG_EXT) /* F8 */
- #define F9 (0x19 + FLAG_EXT) /* F9 */
- #define F10 (0x1A + FLAG_EXT) /* F10 */
- #define F11 (0x1B + FLAG_EXT) /* F11 */
- #define F12 (0x1C + FLAG_EXT) /* F12 */
- /* Control Pad */
- #define PRINTSCREEN (0x1D + FLAG_EXT) /* Print Screen */
- #define PAUSEBREAK (0x1E + FLAG_EXT) /* Pause/Break */
- #define INSERT (0x1F + FLAG_EXT) /* Insert */
- #define DELETE (0x20 + FLAG_EXT) /* Delete */
- #define HOME (0x21 + FLAG_EXT) /* Home */
- #define END (0x22 + FLAG_EXT) /* End */
- #define PAGEUP (0x23 + FLAG_EXT) /* Page Up */
- #define PAGEDOWN (0x24 + FLAG_EXT) /* Page Down */
- #define UP (0x25 + FLAG_EXT) /* Up */
- #define DOWN (0x26 + FLAG_EXT) /* Down */
- #define LEFT (0x27 + FLAG_EXT) /* Left */
- #define RIGHT (0x28 + FLAG_EXT) /* Right */
- /* ACPI keys */
- #define POWER (0x29 + FLAG_EXT) /* Power */
- #define SLEEP (0x2A + FLAG_EXT) /* Sleep */
- #define WAKE (0x2B + FLAG_EXT) /* Wake Up */
- /* Num Pad */
- #define PAD_SLASH (0x2C + FLAG_EXT) /* / */
- #define PAD_STAR (0x2D + FLAG_EXT) /* * */
- #define PAD_MINUS (0x2E + FLAG_EXT) /* - */
- #define PAD_PLUS (0x2F + FLAG_EXT) /* + */
- #define PAD_ENTER (0x30 + FLAG_EXT) /* Enter */
- #define PAD_DOT (0x31 + FLAG_EXT) /* . */
- #define PAD_0 (0x32 + FLAG_EXT) /* 0 */
- #define PAD_1 (0x33 + FLAG_EXT) /* 1 */
- #define PAD_2 (0x34 + FLAG_EXT) /* 2 */
- #define PAD_3 (0x35 + FLAG_EXT) /* 3 */
- #define PAD_4 (0x36 + FLAG_EXT) /* 4 */
- #define PAD_5 (0x37 + FLAG_EXT) /* 5 */
- #define PAD_6 (0x38 + FLAG_EXT) /* 6 */
- #define PAD_7 (0x39 + FLAG_EXT) /* 7 */
- #define PAD_8 (0x3A + FLAG_EXT) /* 8 */
- #define PAD_9 (0x3B + FLAG_EXT) /* 9 */
- #define PAD_UP PAD_8 /* Up */
- #define PAD_DOWN PAD_2 /* Down */
- #define PAD_LEFT PAD_4 /* Left */
- #define PAD_RIGHT PAD_6 /* Right */
- #define PAD_HOME PAD_7 /* Home */
- #define PAD_END PAD_1 /* End */
- #define PAD_PAGEUP PAD_9 /* Page Up */
- #define PAD_PAGEDOWN PAD_3 /* Page Down */
- #define PAD_INS PAD_0 /* Ins */
- #define PAD_MID PAD_5 /* Middle key */
- #define PAD_DEL PAD_DOT /* Del */
头文件中还定义了许多暂时用不到的宏,等用到的时候再说明。
我们知道,按下某些键是能打印出可见的字符的,比如字符键和数字键,但有些键对应的不是可打印字符,这些键就不能直接打印的,而是需要做一些其它的工作。我们暂时先把可以打印的键先打印出来。修改一下Keyboard_Read函数:
- void Keyboard_Read()
- {
- u8 scan_code;
- int make;
- char disp[2];
- Memory_Set(&disp[0],2,0);
- if(kb_input_buffer.count > 0)
- {
- Disable_Int();
- scan_code = *(kb_input_buffer.p_head);
- kb_input_buffer.p_head++;
- kb_input_buffer.count--;
- if(kb_input_buffer.p_head >= kb_input_buffer.buffer + 256)
- {
- kb_input_buffer.p_head = kb_input_buffer.buffer;
- }
- Enable_Int();
- if(scan_code == 0xe1)
- {
- /* 暂时不做任何操作 */
- }
- else if(scan_code == 0xe0)
- {
- /* 暂时不做任何操作 */
- }
- else
- {
- make = (scan_code & NR_SCAN_CODES)? 0 : 1;
- if(make)
- {
- disp[0] = Key_Map[(scan_code & 0x7f) * MAP_COLS];
- Disp_Color_Str(disp,0xa);
- }
- }
- /* Disp_Int(scan_code); */
- }
- }
首先定义了一个局部变量来标识此扫描码是否是Make Code,再定义了一个两字节局部字符数组来作为待打印的空间,先用Memory_Set函数把次空间初始化为0,因为我们打印的串必须以0结尾。在从缓冲区取得扫描码之后,判断一下是否为0xE0和0xE1,是的话先不从处理,日后再说,不是的话,再判断一下是否是Make Code,不是的话就不打印了;是的话,从Key_Map取出相应的ASCII码来打印一下,有一个细节,在从Key_Map中取数据的时候进行了一次与操作,一方面,如果当前扫描码是Break Code,可以把它变成Make Code,这样似乎有点多余,因为已经在if里判断过了是否是Make Code了;另一方面,也是为了避免越界,Key_Map的大小为0x80。
由于新添了一个keymap.h,所以要修改MAKEFILE。
make,运行,按几个可打印的键,结果如下图所示:
嗯,很好的开始。下一步就弄复杂点,与shift键配合搞个组合键之类的。