86Box/src/nvr.c

#include <stdio.h>
#include "ibm.h"
#include "io.h"
#include "nvr.h"
#include "pic.h"
#include "timer.h"
#include "rtc.h"

int oldromset;
int nvrmask=63;
uint8_t nvrram[128];
int nvraddr;

int nvr_dosave = 0;

static int nvr_onesec_time = 0, nvr_onesec_cnt = 0;

void getnvrtime()
{
        time_get(nvrram);
}

void nvr_recalc()
{
        int c;
        int newrtctime;
        c=1<<((nvrram[RTCREGA]&(RTCRS0|RTCRS1|RTCRS2|RTCRS3))-1);
        newrtctime=(int)(RTCCONST * c * (1 << TIMER_SHIFT));
        if (rtctime>newrtctime) rtctime=newrtctime;
}

void nvr_rtc(void *p)
{
        int c;
        if (!(nvrram[RTCREGA]&(RTCRS0|RTCRS1|RTCRS2|RTCRS3)))
        {
                rtctime=0x7fffffff;
                return;
        }
        c=1<<((nvrram[RTCREGA]&(RTCRS0|RTCRS1|RTCRS2|RTCRS3))-1);
        rtctime += (int)(RTCCONST * c * (1 << TIMER_SHIFT));
//        pclog("RTCtime now %f\n",rtctime);
        nvrram[RTCREGC] |= RTCPF;
        if (nvrram[RTCREGB]&RTCPIE)
        {
                nvrram[RTCREGC]|=RTCIRQF;
                if (AMSTRAD) picint(2);
                else         picint(0x100);
//                pclog("RTC int\n");
        }
}

int nvr_update_status = 0;

#define ALARM_DONTCARE	0xc0

int nvr_check_alarm(int nvraddr)
{
        return (nvrram[nvraddr + 1] == nvrram[nvraddr] || (nvrram[nvraddr + 1] & ALARM_DONTCARE) == ALARM_DONTCARE);
}

void nvr_onesec(void *p)
{
        nvr_onesec_cnt++;
        if (nvr_onesec_cnt >= 32768)
        {
                nvr_onesec_cnt = 0;

                /* If sync is disabled, move internal clock ahead by 1 second. */
                if (!(nvrram[RTCREGB] & RTCSET))
                {
                        nvr_update_status = RTCUIP;
                        if (!enable_sync)  rtc_tick();
                }
        }
        else if (nvr_onesec_cnt == 73)	/* 73 of our cycles means 244+1984 us = update in progress time per the specification. */
        {
                if (!(nvrram[RTCREGB] & RTCSET))
                {
                        getnvrtime();
                        /* Clear update status. */
                        nvr_update_status = 0;

                        if (nvr_check_alarm(RTCSECONDS) && nvr_check_alarm(RTCMINUTES) && nvr_check_alarm(RTCHOURS))
                        {
                                nvrram[RTCREGC] |= RTCAF;
                                if (nvrram[RTCREGB] & RTCAIE)
                                {
                                        nvrram[RTCREGC] |= RTCIRQF;
	        	                if (AMSTRAD) picint(2);
        		                else         picint(0x100);
                                }
                        }

                        /* The flag and interrupt should be issued on update ended, not started. */
                        nvrram[RTCREGC] |= RTCUF;
                        if (nvrram[RTCREGB] & RTCUIE)
                        {
                                nvrram[RTCREGC] |= RTCIRQF;
                                if (AMSTRAD) picint(2);
                                else         picint(0x100);
                        }
//                pclog("RTC onesec\n");
                }
        }
        /* This is correct! The real RTC's one second timer operates at 32768 Hz, not 100 Hz! */
        nvr_onesec_time += (int)((1000000.0 / 32768.0) * TIMER_USEC);
}

void writenvr(uint16_t addr, uint8_t val, void *priv)
{
        int c, old;
//        printf("Write NVR %03X %02X %02X %04X:%04X %i\n",addr,nvraddr,val,cs>>4,pc,ins);
        if (addr&1)
        {
                if (nvraddr==RTCREGC || nvraddr==RTCREGD)  return; /* Registers C and D are read-only. There's no reason to continue. */
//                if (nvraddr == 0x33) pclog("NVRWRITE33 %02X %04X:%04X %i\n",val,CS,pc,ins);
                if (nvraddr > RTCREGD && nvrram[nvraddr] != val)
                   nvr_dosave = 1;
                
		old = nvrram[nvraddr];
                nvrram[nvraddr]=val;

                if (nvraddr==RTCREGA)
                {
//                        pclog("NVR rate %i\n",val&0xF);
                        if (val&(RTCRS0|RTCRS1|RTCRS2|RTCRS3))
                        {
                                c=1<<((val&(RTCRS0|RTCRS1|RTCRS2|RTCRS3))-1);
                                rtctime += (int)(RTCCONST * c * (1 << TIMER_SHIFT));
                        }
                        else
                           rtctime = 0x7fffffff;
                }
		else
		{
                        if (nvraddr==RTCREGB)
                        {
                                if (((old ^ val) & RTCSET) && (val & RTCSET))
                                {
                                        nvrram[RTCREGA] &= ~RTCUIP;             /* This has to be done according to the datasheet. */
                                        nvrram[RTCREGB] &= ~RTCUIE;             /* This also has to happen per the specification. */
                                }
                        }

                        if ((nvraddr < RTCREGA) || (nvraddr == RTCCENTURY))
                        {
                                if ((nvraddr != 1) && (nvraddr != 3) && (nvraddr != 5))
                                {
                                        if ((old != val) && !enable_sync)
                                        {
                                                time_update(nvrram, nvraddr);
                                                nvr_dosave = 1;
                                        }
                                }
                        }
                }
        }
        else        nvraddr=val&nvrmask;
}

uint8_t readnvr(uint16_t addr, void *priv)
{
        uint8_t temp;
//        printf("Read NVR %03X %02X %02X %04X:%04X\n",addr,nvraddr,nvrram[nvraddr],cs>>4,pc);
        if (addr&1)
        {
                if (nvraddr==RTCREGA) return ((nvrram[RTCREGA] & 0x7F) | nvr_update_status);
                if (nvraddr==RTCREGD) nvrram[RTCREGD]|=RTCVRT;
                if (nvraddr==RTCREGC)
                {
                        if (AMSTRAD) picintc(2);
                        else         picintc(0x100);
                        temp=nvrram[RTCREGC];
                        nvrram[RTCREGC]=0; /* All flags in register C are unused (always 0) or cleared on read */
                        return temp;
                }
//                if (AMIBIOS && nvraddr==0x36) return 0;
//                if (nvraddr==0xA) nvrram[0xA]^=0x80;
                return nvrram[nvraddr];
        }
        return nvraddr;
}

void loadnvr()
{
        FILE *f;
        int c;
        nvrmask=63;
        oldromset=romset;
        switch (romset)
        {
                case ROM_PC1512:      f = romfopen("nvr/pc1512.nvr",      "rb"); break;
                case ROM_PC1640:      f = romfopen("nvr/pc1640.nvr",      "rb"); break;
                case ROM_PC200:       f = romfopen("nvr/pc200.nvr",       "rb"); break;
                case ROM_PC2086:      f = romfopen("nvr/pc2086.nvr",      "rb"); break;
                case ROM_PC3086:      f = romfopen("nvr/pc3086.nvr",      "rb"); break;                
                case ROM_IBMAT:       f = romfopen("nvr/at.nvr",          "rb"); break;
                case ROM_IBMPS1_2011: f = romfopen("nvr/ibmps1_2011.nvr", "rb"); /*nvrmask = 127; */break;
                case ROM_IBMPS1_2121: f = romfopen("nvr/ibmps1_2121.nvr", "rb"); nvrmask = 127; break;
                case ROM_CMDPC30:     f = romfopen("nvr/cmdpc30.nvr",     "rb"); nvrmask = 127; break;
                case ROM_AMI286:      f = romfopen("nvr/ami286.nvr",      "rb"); nvrmask = 127; break;
                case ROM_AWARD286:    f = romfopen("nvr/award286.nvr",    "rb"); nvrmask = 127; break;
                case ROM_DELL200:     f = romfopen("nvr/dell200.nvr",     "rb"); nvrmask = 127; break;
                case ROM_IBMAT386:    f = romfopen("nvr/at386.nvr",       "rb"); nvrmask = 127; break;
                case ROM_DESKPRO_386: f = romfopen("nvr/deskpro386.nvr",  "rb"); break;
                case ROM_ACER386:     f = romfopen("nvr/acer386.nvr",     "rb"); nvrmask = 127; break;
                case ROM_MEGAPC:      f = romfopen("nvr/megapc.nvr",      "rb"); nvrmask = 127; break;
                case ROM_AMI386:      f = romfopen("nvr/ami386.nvr",      "rb"); nvrmask = 127; break;
                case ROM_AMI486:      f = romfopen("nvr/ami486.nvr",      "rb"); nvrmask = 127; break;
                case ROM_WIN486:      f = romfopen("nvr/win486.nvr",      "rb"); nvrmask = 127; break;
                case ROM_PCI486:      f = romfopen("nvr/hot-433.nvr",     "rb"); nvrmask = 127; break;
                case ROM_SIS496:      f = romfopen("nvr/sis496.nvr",      "rb"); nvrmask = 127; break;
                case ROM_430VX:       f = romfopen("nvr/430vx.nvr",       "rb"); nvrmask = 127; break;
                case ROM_REVENGE:     f = romfopen("nvr/revenge.nvr",     "rb"); nvrmask = 127; break;
                case ROM_ENDEAVOR:    f = romfopen("nvr/endeavor.nvr",    "rb"); nvrmask = 127; break;
                case ROM_PX386:       f = romfopen("nvr/px386.nvr",       "rb"); nvrmask = 127; break;
                case ROM_DTK386:      f = romfopen("nvr/dtk386.nvr",      "rb"); nvrmask = 127; break;
                case ROM_DTK486:      f = romfopen("nvr/dtk486.nvr",      "rb"); nvrmask = 127; break;
                case ROM_R418:        f = romfopen("nvr/r418.nvr",        "rb"); nvrmask = 127; break;
                case ROM_586MC1:      f = romfopen("nvr/586mc1.nvr",      "rb"); nvrmask = 127; break;
                case ROM_PLATO:       f = romfopen("nvr/plato.nvr",       "rb"); nvrmask = 127; break;
                case ROM_MB500N:      f = romfopen("nvr/mb500n.nvr",      "rb"); nvrmask = 127; break;
                case ROM_P54TP4XE:    f = romfopen("nvr/p54tp4xe.nvr",    "rb"); nvrmask = 127; break;
                case ROM_ACERM3A:     f = romfopen("nvr/acerm3a.nvr",     "rb"); nvrmask = 127; break;
                case ROM_ACERV35N:    f = romfopen("nvr/acerv35n.nvr",    "rb"); nvrmask = 127; break;
                case ROM_P55T2P4:     f = romfopen("nvr/p55t2p4.nvr",     "rb"); nvrmask = 127; break;
                case ROM_P55TVP4:     f = romfopen("nvr/p55tvp4.nvr",     "rb"); nvrmask = 127; break;
                case ROM_P55VA:       f = romfopen("nvr/p55va.nvr",       "rb"); nvrmask = 127; break;
                case ROM_440FX:       f = romfopen("nvr/440fx.nvr",       "rb"); nvrmask = 127; break;
                case ROM_KN97:        f = romfopen("nvr/kn97.nvr",        "rb"); nvrmask = 127; break;
                default: return;
        }
        if (!f)
        {
                memset(nvrram,0xFF,128);
                if (!enable_sync)
                {
                        nvrram[RTCSECONDS] = nvrram[RTCMINUTES] = nvrram[RTCHOURS] = 0;
                        nvrram[RTCDOM] = nvrram[RTCMONTH] = 1;
                        nvrram[RTCYEAR] = BCD(80);
                        nvrram[RTCCENTURY] = BCD(19);
                        nvrram[RTCREGB]=RTC2412;
                }
                return;
        }
        fread(nvrram,128,1,f);
        if (!enable_sync)  time_update(nvrram, 0xFF);        /* Update the internal clock state based on the NVR registers. */
        fclose(f);
        nvrram[RTCREGA]=(RTCRS1|RTCRS2);
        nvrram[RTCREGB]=RTC2412;
        c=1<<((nvrram[RTCREGA]&(RTCRS0|RTCRS1|RTCRS2|RTCRS3))-1);
        rtctime += (int)(RTCCONST * c * (1 << TIMER_SHIFT));
}
void savenvr()
{
        FILE *f;
        switch (oldromset)
        {
                case ROM_PC1512:      f = romfopen("nvr/pc1512.nvr",      "wb"); break;
                case ROM_PC1640:      f = romfopen("nvr/pc1640.nvr",      "wb"); break;
                case ROM_PC200:       f = romfopen("nvr/pc200.nvr",       "wb"); break;
                case ROM_PC2086:      f = romfopen("nvr/pc2086.nvr",      "wb"); break;
                case ROM_PC3086:      f = romfopen("nvr/pc3086.nvr",      "wb"); break;
                case ROM_IBMAT:       f = romfopen("nvr/at.nvr",          "wb"); break;
                case ROM_IBMPS1_2011: f = romfopen("nvr/ibmps1_2011.nvr", "wb"); break;
                case ROM_IBMPS1_2121: f = romfopen("nvr/ibmps1_2121.nvr", "wb"); break;
                case ROM_CMDPC30:     f = romfopen("nvr/cmdpc30.nvr",     "wb"); break;                
                case ROM_AMI286:      f = romfopen("nvr/ami286.nvr",      "wb"); break;
                case ROM_AWARD286:    f = romfopen("nvr/award286.nvr",    "wb"); break;
                case ROM_DELL200:     f = romfopen("nvr/dell200.nvr",     "wb"); break;
                case ROM_IBMAT386:    f = romfopen("nvr/at386.nvr",       "wb"); break;
                case ROM_DESKPRO_386: f = romfopen("nvr/deskpro386.nvr",  "wb"); break;
                case ROM_ACER386:     f = romfopen("nvr/acer386.nvr",     "wb"); break;
                case ROM_MEGAPC:      f = romfopen("nvr/megapc.nvr",      "wb"); break;
                case ROM_AMI386:      f = romfopen("nvr/ami386.nvr",      "wb"); break;
                case ROM_AMI486:      f = romfopen("nvr/ami486.nvr",      "wb"); break;
                case ROM_WIN486:      f = romfopen("nvr/win486.nvr",      "wb"); break;
                case ROM_PCI486:      f = romfopen("nvr/hot-433.nvr",     "wb"); break;
                case ROM_SIS496:      f = romfopen("nvr/sis496.nvr",      "wb"); break;
                case ROM_430VX:       f = romfopen("nvr/430vx.nvr",       "wb"); break;
                case ROM_REVENGE:     f = romfopen("nvr/revenge.nvr",     "wb"); break;
                case ROM_ENDEAVOR:    f = romfopen("nvr/endeavor.nvr",    "wb"); break;
                case ROM_PX386:       f = romfopen("nvr/px386.nvr",       "wb"); break;
                case ROM_DTK386:      f = romfopen("nvr/dtk386.nvr",      "wb"); break;
                case ROM_DTK486:      f = romfopen("nvr/dtk486.nvr",      "wb"); break;
                case ROM_R418:        f = romfopen("nvr/r418.nvr",        "wb"); break;
                case ROM_586MC1:      f = romfopen("nvr/586mc1.nvr",      "wb"); break;
                case ROM_PLATO:       f = romfopen("nvr/plato.nvr",       "wb"); break;
                case ROM_MB500N:      f = romfopen("nvr/mb500n.nvr",      "wb"); break;
                case ROM_P54TP4XE:    f = romfopen("nvr/p54tp4xe.nvr",    "wb"); break;
                case ROM_ACERM3A:     f = romfopen("nvr/acerm3a.nvr",     "wb"); break;
                case ROM_ACERV35N:    f = romfopen("nvr/acerv35n.nvr",    "wb"); break;
                case ROM_P55T2P4:     f = romfopen("nvr/p55t2p4.nvr",     "wb"); break;
                case ROM_P55TVP4:     f = romfopen("nvr/p55tvp4.nvr",     "wb"); break;
                case ROM_P55VA:       f = romfopen("nvr/p55va.nvr",       "wb"); break;
                case ROM_440FX:       f = romfopen("nvr/440fx.nvr",       "wb"); break;
                case ROM_KN97:        f = romfopen("nvr/kn97.nvr",        "wb"); break;
                default: return;
        }
        fwrite(nvrram,128,1,f);
        fclose(f);
}

void nvr_init()
{
        io_sethandler(0x0070, 0x0002, readnvr, NULL, NULL, writenvr, NULL, NULL,  NULL);
        timer_add(nvr_rtc, &rtctime, TIMER_ALWAYS_ENABLED, NULL);
        timer_add(nvr_onesec, &nvr_onesec_time, TIMER_ALWAYS_ENABLED, NULL);
}