Archipelago » qemu

/*

 * QEMU MC146818 RTC emulation

 * 

 * Copyright (c) 2003-2004 Fabrice Bellard

 * 

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to deal

 * in the Software without restriction, including without limitation the rights

 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL

 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

 * THE SOFTWARE.

 */

#include <stdlib.h>

#include <stdio.h>

#include <stdarg.h>

#include <string.h>

#include <getopt.h>

#include <inttypes.h>

#include <unistd.h>

#include <sys/mman.h>

#include <fcntl.h>

#include <signal.h>

#include <time.h>

#include <sys/time.h>

#include <malloc.h>

#include <termios.h>

#include <sys/poll.h>

#include <errno.h>

#include <sys/wait.h>

#include <netinet/in.h>

#include "cpu.h"

#include "vl.h"

//#define DEBUG_CMOS

#define RTC_SECONDS             0

#define RTC_SECONDS_ALARM       1

#define RTC_MINUTES             2

#define RTC_MINUTES_ALARM       3

#define RTC_HOURS               4

#define RTC_HOURS_ALARM         5

#define RTC_ALARM_DONT_CARE    0xC0

#define RTC_DAY_OF_WEEK         6

#define RTC_DAY_OF_MONTH        7

#define RTC_MONTH               8

#define RTC_YEAR                9

#define RTC_REG_A               10

#define RTC_REG_B               11

#define RTC_REG_C               12

#define RTC_REG_D               13

/* PC cmos mappings */

#define REG_IBM_CENTURY_BYTE        0x32

#define REG_IBM_PS2_CENTURY_BYTE    0x37

RTCState rtc_state;

static void cmos_ioport_write(void *opaque, uint32_t addr, uint32_t data)

{

    RTCState *s = opaque;

    if ((addr & 1) == 0) {

        s->cmos_index = data & 0x7f;

    } else {

#ifdef DEBUG_CMOS

        printf("cmos: write index=0x%02x val=0x%02x\n",

               s->cmos_index, data);

#endif        

        switch(addr) {

        case RTC_SECONDS_ALARM:

        case RTC_MINUTES_ALARM:

        case RTC_HOURS_ALARM:

            /* XXX: not supported */

            s->cmos_data[s->cmos_index] = data;

            break;

        case RTC_SECONDS:

        case RTC_MINUTES:

        case RTC_HOURS:

        case RTC_DAY_OF_WEEK:

        case RTC_DAY_OF_MONTH:

        case RTC_MONTH:

        case RTC_YEAR:

            s->cmos_data[s->cmos_index] = data;

            break;

        case RTC_REG_A:

        case RTC_REG_B:

            s->cmos_data[s->cmos_index] = data;

            break;

        case RTC_REG_C:

        case RTC_REG_D:

            /* cannot write to them */

            break;

        default:

            s->cmos_data[s->cmos_index] = data;

            break;

        }

    }

}

static inline int to_bcd(int a)

{

    return ((a / 10) << 4) | (a % 10);

}

static void cmos_update_time(RTCState *s)

{

    struct tm *tm;

    time_t ti;

    ti = time(NULL);

    tm = gmtime(&ti);

    s->cmos_data[RTC_SECONDS] = to_bcd(tm->tm_sec);

    s->cmos_data[RTC_MINUTES] = to_bcd(tm->tm_min);

    s->cmos_data[RTC_HOURS] = to_bcd(tm->tm_hour);

    s->cmos_data[RTC_DAY_OF_WEEK] = to_bcd(tm->tm_wday);

    s->cmos_data[RTC_DAY_OF_MONTH] = to_bcd(tm->tm_mday);

    s->cmos_data[RTC_MONTH] = to_bcd(tm->tm_mon + 1);

    s->cmos_data[RTC_YEAR] = to_bcd(tm->tm_year % 100);

    s->cmos_data[REG_IBM_CENTURY_BYTE] = to_bcd((tm->tm_year / 100) + 19);

    s->cmos_data[REG_IBM_PS2_CENTURY_BYTE] = s->cmos_data[REG_IBM_CENTURY_BYTE];

}

static uint32_t cmos_ioport_read(void *opaque, uint32_t addr)

{

    RTCState *s = opaque;

    int ret;

    if ((addr & 1) == 0) {

        return 0xff;

    } else {

        switch(s->cmos_index) {

        case RTC_SECONDS:

        case RTC_MINUTES:

        case RTC_HOURS:

        case RTC_DAY_OF_WEEK:

        case RTC_DAY_OF_MONTH:

        case RTC_MONTH:

        case RTC_YEAR:

        case REG_IBM_CENTURY_BYTE:

        case REG_IBM_PS2_CENTURY_BYTE:

            cmos_update_time(s);

            ret = s->cmos_data[s->cmos_index];

            break;

        case RTC_REG_A:

            ret = s->cmos_data[s->cmos_index];

            /* toggle update-in-progress bit for Linux (same hack as

               plex86) */

            s->cmos_data[RTC_REG_A] ^= 0x80; 

            break;

        case RTC_REG_C:

            ret = s->cmos_data[s->cmos_index];

            pic_set_irq(s->irq, 0);

            s->cmos_data[RTC_REG_C] = 0x00; 

            break;

        default:

            ret = s->cmos_data[s->cmos_index];

            break;

        }

#ifdef DEBUG_CMOS

        printf("cmos: read index=0x%02x val=0x%02x\n",

               s->cmos_index, ret);

#endif

        return ret;

    }

}

void rtc_timer(void)

{

    RTCState *s = &rtc_state;

    if (s->cmos_data[RTC_REG_B] & 0x50) {

        pic_set_irq(s->irq, 1);

    }

}

void rtc_init(int base, int irq)

{

    RTCState *s = &rtc_state;

    cmos_update_time(s);

    s->irq = irq;

    s->cmos_data[RTC_REG_A] = 0x26;

    s->cmos_data[RTC_REG_B] = 0x02;

    s->cmos_data[RTC_REG_C] = 0x00;

    s->cmos_data[RTC_REG_D] = 0x80;

    register_ioport_write(base, 2, 1, cmos_ioport_write, s);

    register_ioport_read(base, 2, 1, cmos_ioport_read, s);

}