/*
 * Copyright 2004-2011, Axel Dörfler, axeld@pinc-software.de.
 * Distributed under the terms of the MIT License.
 */


#include "keyboard.h"
#include "bios.h"

#include <boot/platform.h>


/*!     Note, checking for keys doesn't seem to work in graphics
        mode, at least in Bochs.
*/
static uint16
check_for_key(void)
{
        bios_regs regs;
        regs.eax = 0x0100;
        call_bios(0x16, &regs);

        // the zero flag is set when there is no key stroke waiting for us
        if (regs.flags & ZERO_FLAG)
                return 0;

        // remove the key from the buffer
        regs.eax = 0;
        call_bios(0x16, &regs);

        return regs.eax & 0xffff;
}


extern "C" void
clear_key_buffer(void)
{
        while (check_for_key() != 0)
                ;
}


extern "C" union key
wait_for_key(void)
{
        union key key;
        do {
                key.ax = check_for_key();
        } while (key.ax == 0);

        return key;
}


extern "C" uint32
check_for_boot_keys(void)
{
        bios_regs regs;
        uint32 options = 0;
        uint32 keycode = 0;
        regs.eax = 0x0200;
        call_bios(0x16, &regs);
                // Read Keyboard flags. bit 0 LShift, bit 1 RShift
        if ((regs.eax & 0x03) != 0) {
                // LShift or RShift - option menu
                options |= BOOT_OPTION_MENU;
        } else {
                keycode = boot_key_in_keyboard_buffer();
                if (keycode == 0x3920) {
                        // space - option menu
                        options |= BOOT_OPTION_MENU;
                } else if (keycode == 0x011B) {
                        // ESC - debug output
                        options |= BOOT_OPTION_DEBUG_OUTPUT;
                }
        }

        dprintf("options = %d\n", options);
        return options;
}