xv6

port of xv6 to x86-64
git clone http://frotz.net/git/xv6.git
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kbd.c (925B)

      1 #include "types.h"
      2 #include "x86.h"
      3 #include "defs.h"
      4 #include "kbd.h"
      5 
      6 int
      7 kbdgetc(void)
      8 {
      9   static uint shift;
     10   static uchar *charcode[4] = {
     11     normalmap, shiftmap, ctlmap, ctlmap
     12   };
     13   uint st, data, c;
     14 
     15   st = inb(KBSTATP);
     16   if((st & KBS_DIB) == 0)
     17     return -1;
     18   data = inb(KBDATAP);
     19 
     20   if(data == 0xE0){
     21     shift |= E0ESC;
     22     return 0;
     23   } else if(data & 0x80){
     24     // Key released
     25     data = (shift & E0ESC ? data : data & 0x7F);
     26     shift &= ~(shiftcode[data] | E0ESC);
     27     return 0;
     28   } else if(shift & E0ESC){
     29     // Last character was an E0 escape; or with 0x80
     30     data |= 0x80;
     31     shift &= ~E0ESC;
     32   }
     33 
     34   shift |= shiftcode[data];
     35   shift ^= togglecode[data];
     36   c = charcode[shift & (CTL | SHIFT)][data];
     37   if(shift & CAPSLOCK){
     38     if('a' <= c && c <= 'z')
     39       c += 'A' - 'a';
     40     else if('A' <= c && c <= 'Z')
     41       c += 'a' - 'A';
     42   }
     43   return c;
     44 }
     45 
     46 void
     47 kbdintr(void)
     48 {
     49   consoleintr(kbdgetc);
     50 }