kb.c

 #include "isr.h"

#define RSHIFT 54;
#define LSHIFT 42;

unsigned char US_KEYBOARD_LAYOUT[128] =
{
    0,  27, '1', '2', '3', '4', '5', '6', '7', '8',	/* 9 */
  '9', '0', '-', '=', '\b',	/* Backspace */
  '\t',			/* Tab */
  'q', 'w', 'e', 'r',	/* 19 */
  't', 'y', 'u', 'i', 'o', 'p', '[', ']', '\n',	/* Enter key */
    0,			/* 29   - Control */
  'a', 's', 'd', 'f', 'g', 'h', 'j', 'k', 'l', ';',	/* 39 */
 '\'', '`',   0,		/* Left shift */
 '\\', 'z', 'x', 'c', 'v', 'b', 'n',			/* 49 */
  'm', ',', '.', '/',   0,				/* Right shift */
  '*',
    0,	/* Alt */
  ' ',	/* Space bar */
    0,	/* Caps lock */
    0,	/* 59 - F1 key ... > */
    0,   0,   0,   0,   0,   0,   0,   0,
    0,	/* < ... F10 */
    0,	/* 69 - Num lock*/
    0,	/* Scroll Lock */
    0,	/* Home key */
    0,	/* Up Arrow */
    0,	/* Page Up */
  '-',
    0,	/* Left Arrow */
    0,
    0,	/* Right Arrow */
  '+',
    0,	/* 79 - End key*/
    0,	/* Down Arrow */
    0,	/* Page Down */
    0,	/* Insert Key */
    0,	/* Delete Key */
    0,   0,   0,
    0,	/* F11 Key */
    0,	/* F12 Key */
    0,	/* All other keys are undefined */
};

unsigned char US_KEYBOARD_LAYOUT_UPPER[128] =
{
0,  0, '!', '"', '£', '$', '%', '^', '&', '*',   /* 9 */
  '(', ')', '_', '+', '\b', '\t',
  'Q', 'W', 'E', 'R',
  'T', 'Y', 'U', 'I', 'O', 'P', '{', '}', '\n',      /* Enter key */
    0,         /* 29   - Control */
  'A', 'S', 'D', 'F', 'G', 'H', 'J', 'K', 'L', ';',   /* 39 */
'|', '¬',   42,      /* Left shift */
'\\', 'Z', 'X', 'C', 'V', 'B', 'N',         /* 49 */
  'M', '<', '>', '?',   0,               /* Right shift */
  0,
    0,   /* Alt */
  ' ',   /* Space bar */
    58,   /* Caps lock */
    0,   /* 59 - F1 key ... > */
    0,   0,   0,   0,   0,   0,   0,   0,
    0,   /* < ... F10 */
    0,   /* 69 - Num lock*/
    0,   /* Scroll Lock */
    0,   /* Home key */
    0,   /* Up Arrow */
    0,   /* Page Up */
  '-',
    0,   /* Left Arrow */
    0,
    0,   /* Right Arrow */
  '+',
    0,   /* 79 - End key*/
    0,   /* Down Arrow */
    0,   /* Page Down */
    0,   /* Insert Key */
    0,   /* Delete Key */
    0,   0,   0,
    0,   /* F11 Key */
    0,   /* F12 Key */
    0,   /* All other keys are undefined */
};



static void keydown_callback(registers_t regs)
{
    /* Declared volatile to prevent caching of the variable value in memory.  That would be bad and this loop would never break...*/
   volatile unsigned char scancode;
   unsigned char statuscode;
   scancode = inportb(0x60);
   statuscode = inportb(0x64);
   volatile unsigned int scanint = scancode;
   unsigned int uppercase = 0;
   /*   This is crude but mostly for testing.
        If we read a shift, busywait until we get a non-shift character and set our uppercase flag to true */
   while(scanint == 54 || scanint == 42)
   {
        uppercase = 1;
        scancode = inportb(0x60);
        statuscode = inportb(0x64);
        scanint = scancode;
   }
   if(scancode & 0x80)
   {
        /* Ignore this for now */
   }
   else
   {
       if(uppercase == 1)
       {
           putch(US_KEYBOARD_LAYOUT_UPPER[scancode]);
       }
       else
       {
	        putch(US_KEYBOARD_LAYOUT[scancode]);
       }
   }
}

void init_kb(unsigned int frequency)
{
   register_interrupt_handler(IRQ1, &keydown_callback);

}