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/* bkerndev - Bran's Kernel Development Tutorial
*  By:   Brandon F. ([email protected])
*  Desc: Keyboard driver
*
*  Notes: No warranty expressed or implied. Use at own risk. */
#include "hal.h"

/* KBDUS means US Keyboard Layout. This is a scancode table
*  used to layout a standard US keyboard. I have left some
*  comments in to give you an idea of what key is what, even
*  though I set it's array index to 0. You can change that to
*  whatever you want using a macro, if you wish! */
unsigned char kbdus[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 */
};

/* Handles the keyboard interrupt */
void keyboard_handler(struct regs *r)
{
    unsigned char scancode;

    /* Read from the keyboard's data buffer */
    scancode = inb(0x60);
        /* Here, a key was just pressed. Please note that if you
        *  hold a key down, you will get repeated key press
        *  interrupts. */

        /* Just to show you how this works, we simply translate
        *  the keyboard scancode into an ASCII value, and then
        *  display it to the screen. You can get creative and
        *  use some flags to see if a shift is pressed and use a
        *  different layout, or you can add another 128 entries
        *  to the above layout to correspond to 'shift' being
        *  held. If shift is held using the larger lookup table,
        *  you would add 128 to the scancode when you look for it */
        kputc(kbdus[scancode]);
}

/* Installs the keyboard handler into IRQ1 */
void keyboard_install()
{
    registerInterruptHandler(IRQ1, keyboard_handler, NF);
}