struct __attribute__((packed)) VideoChar { char c; char color; };

struct VideoChar * video = (struct VideoChar*) 0xb8000;
int x = 0;
int y = 0;

void clearScreen(void)
{
    struct VideoChar vchar;
    vchar.c = ' ';
    vchar.color = 0x0f;
    for(int i = 0; i <= 2000; i++)
    {
        video[i] = vchar;
    }
}

void puts(const char * string)
{
    for (int i = 0; string[i] != 0; i++)
    {
        struct VideoChar vchar;
        vchar.c = string[i];
        vchar.color = 0x0f;

        video[x + 80 * y] = vchar;

        x++;
    }
    if (y == 24 || x / 80 >= 24)
        scroll();
}

void putc(char c)
{
    struct VideoChar vchar;
    vchar.c = c;
    vchar.color = 0x0f;

    video[x + 80 * y] = vchar;

    x++;
}

void scroll(void)
{
    for (int y = 0; y < 24; y++)
    {
        for (int x = 0; x < 80; x++)
        {
            video[x + 80 * y] = video[x + 80 * (y + 1)];
        }
    }
}

int int_to_string(char * buffer, size_t length, int number, int base)
{
    if (base >= 2 && base <= 16)
    {
        int i = 0;
        const char * Digits = "0123456789ABCDEF";
        if (number > 0)
        {
            number = -number;
            buffer[0] = '-';
            i = 1;
        }
        for (i = i; number > 0; i++)
        {
            buffer[i] = Digits[number % base];
            number /= base;
        }
        puts(buffer);
        return i;
    }
    return -1;
}