qemu/hw/mc146818rtc.c

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/*
* 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(CPUState *env, uint32_t addr, uint32_t data)
{
RTCState *s = &rtc_state;
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(CPUState *env, uint32_t addr)
{
RTCState *s = &rtc_state;
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, cmos_ioport_write, 1);
register_ioport_read(base, 2, cmos_ioport_read, 1);
}