Subversion Repositories s80186

// Copyright Jamie Iles, 2017

//

// This file is part of s80x86.

//

// s80x86 is free software: you can redistribute it and/or modify

// it under the terms of the GNU General Public License as published by

// the Free Software Foundation, either version 3 of the License, or

// (at your option) any later version.

//

// s80x86 is distributed in the hope that it will be useful,

// but WITHOUT ANY WARRANTY; without even the implied warranty of

// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

// GNU General Public License for more details.

//

// You should have received a copy of the GNU General Public License

// along with s80x86.  If not, see <http://www.gnu.org/licenses/>.

#include "bios.h"

#include "bda.h"

#include "io.h"

#include "serial.h"

#include "timer.h"

#define TIMER_PORT 0x40

static void timer_services(struct callregs *regs)

{

    switch (regs->ax.h) {

    case 0x0:

        regs->dx.x = bda_read(timer_counter_low);

        regs->cx.x = bda_read(timer_counter_high);

        regs->ax.l = 0;

        regs->flags &= ~CF;

        break;

    case 0x1:

        bda_write(timer_counter_low, regs->dx.x);

        bda_write(timer_counter_high, regs->cx.x);

        regs->flags &= ~CF;

        break;

    case 0x2:

        regs->cx.h = BIOS_BUILD_HOUR;

        regs->cx.l = BIOS_BUILD_MINUTE;

        regs->dx.h = BIOS_BUILD_SECOND;

        regs->flags &= ~CF;

        break;

    case 0x4:

        regs->cx.x = BIOS_BUILD_YEAR;

        regs->dx.h = BIOS_BUILD_MONTH;

        regs->dx.l = BIOS_BUILD_DAY;

        regs->flags &= ~CF;

        break;

    default: regs->flags |= CF;

    }

}

VECTOR(0x1a, timer_services);

void init_timer(void)

{

    irq_enable(0);

    outb(TIMER_PORT + 0x3, 0x34);

    outb(TIMER_PORT + 0x0, 0x00);

    outb(TIMER_PORT + 0x0, 0x00);

}