kb.c

#include "asmhelpers.h"
#include "kb.h"

extern char START_BSS[], END_BSS[];



u16
scancode_to_ascii(u8 scancode){

    static const unsigned char kbdus[128] = {
      0,ESC,'1','2','3','4','5','6','7','8','9','0','-','=',BKSP,          // 00-0E
      TAB,'q','w','e','r','t','y','u','i','o','p','[',']',ENTER,           // 0F-1C
      0/*CTRL*/,'a','s','d','f','g','h','j','k','l',';','\'','`',          // 1D-29
      0/*LSHIFT*/,'\\','z','x','c','v','b','n','m',',','.','/',0/*RSHIFT*/,// 2A-36
      0/*PTSCR*/,0/*ALT*/,' ', CAPSLK,                                     // 37-3A
      F1,F2,F3,F4,F5,F6,F7,F8,F9,F10,NUMLK,SCRLLK,                         // 3B-46
      PAD7,PAD8,PAD9,'-', PAD4,PAD5,PAD6,'+', PAD1,PAD2,PAD3,PAD0,DEL,     // 47-53
      0,0,0,F11,F12,                                                       // 54-58
      0, /* All other keys are undefined */
    };


    static const unsigned char kbdus_shift[128] = {
      0,ESC,'!','@','#','$','%','^','&','*','(',')','_','+',BKSP,          // 00-0E
      TAB,'Q','W','E','R','T','Y','U','I','O','P','{','}',ENTER,           // 0F-1C
      0/*CTRL*/,'A','S','D','F','G','H','J','K','L',':','\"','~',          // 1D-29
      0/*LSHIFT*/,'\\','Z','X','C','V','B','N','M','<','>','?',0/*RSHIFT*/,// 2A-36
      0/*PTSCR*/,0/*ALT*/,' ', CAPSLK,                                     // 37-3A
      F1,F2,F3,F4,F5,F6,F7,F8,F9,F10,NUMLK,SCRLLK,                         // 3B-46
      '7','8','9','-', '4','5','6','+', '1','2','3','0','.',               // 47-53
      0,0,0,F11,F12,                                                       // 54-58
      0,
    };
    static int depressed[256] = { 0 }; // currently depressed keys
    static int extended = 0;
    if (scancode == 0) {
        return 0;
    } else if (scancode == 0xe0) {
        extended = 1;
        return 0;
    } else if (scancode & 0x80) { // released
        depressed[scancode & 0x7f] = 0;
        extended = 0;
        return 0;
    }

    depressed[scancode] = 1;

    int shifts = 0;

    if (depressed[CTRL]) shifts |= CTRL_FLAG;
    if (depressed[ALT]) shifts |= ALT_FLAG;
    if (depressed[LSHIFT] || depressed[RSHIFT]) shifts |= SHIFT_FLAG;


    u16 ch = 0;

    if (extended) {
        switch (scancode) {
        case 0x47: ch = HOME; break;
        case 0x48: ch = UP; break;
        case 0x49: ch = PGUP; break;
    //            case 0x4a: ch = ???; break;
        case 0x4b: ch = LEFT; break;
        case 0x4c: ch = CENTER; break;
        case 0x4d: ch = RIGHT; break;
    //            case 0x4e: ch = ???; break;
        case 0x4f: ch = END; break;
        case 0x50: ch = DOWN; break;
        case 0x51: ch = PGDN; break;
        case 0x52: ch = INS; break;
        case 0x53: ch = DEL; break;
        default: break;
        };
    } else {
        if (depressed[LSHIFT] || depressed[RSHIFT]) {
            ch = kbdus_shift[scancode];
        } else {
            ch = kbdus[scancode];
        }
    }

    if (ch > 0){
        return  ch | shifts;
    }

    return 0;
}