bios.c

/*
 * bios.c - BIOS services
 *
 * author: luke8086
 * license: GPL-2
 */

#include "intr.h"
#include "bios.h"

void
toggle_cursor(int visible)
{
    struct regs regs = {
        .ah = 0x01,
        .ch = (visible ? 0x06 : 0x20 ),
        .cl = (visible ? 0x07 : 0x00 ),
    };

    intr(0x10, &regs);
}

void
move_cursor(int x, int y)
{
    struct regs regs = {
        .ah = 0x02,
        .bh = 0x00,
        .dh = y,
        .dl = x,
    };

    intr(0x10, &regs);
}

void
put_char(char ascii)
{
    struct regs regs = {
        .ah = 0x0e,
        .al = ascii,
        .bh = 0x00,
    };
 
    intr(0x10, &regs);
}

int
check_keystroke(void)
{
    struct regs regs = { .ah = 0x01 };

    intr(0x16, &regs);

    return !(regs.eflags & 0x0040);
}

struct keystroke
get_keystroke(void)
{
    struct regs regs = { .ah = 0x00 };

    intr(0x16, &regs);

    struct keystroke ret = {
        .scancode = regs.ah,
        .ascii    = regs.al,
    };

    return ret;
}

uint32_t
get_time(void)
{
    struct regs regs = { .ah = 0x00 };

    intr(0x1a, &regs);

    return ((regs.cx << 16) | regs.dx);
}