/*
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/*
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* disk.c -- disk simulation
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* disk.c -- disk simulation
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*/
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*/
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#include <stdio.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <stdlib.h>
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#include <string.h>
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#include <string.h>
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#include <setjmp.h>
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#include <setjmp.h>
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#include "common.h"
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#include "common.h"
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#include "console.h"
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#include "console.h"
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#include "error.h"
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#include "error.h"
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#include "except.h"
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#include "except.h"
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#include "cpu.h"
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#include "cpu.h"
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#include "timer.h"
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#include "timer.h"
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#include "disk.h"
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#include "disk.h"
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static Bool debug = false;
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static Bool debug = false;
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static FILE *diskImage;
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static FILE *diskImage;
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static long totalSectors;
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static long totalSectors;
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static Word diskCtrl;
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static Word diskCtrl;
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static Word diskCnt;
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static Word diskCnt;
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static Word diskSct;
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static Word diskSct;
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static Word diskCap;
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static Word diskCap;
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static Byte diskBuffer[8 * SECTOR_SIZE];
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static Byte diskBuffer[8 * SECTOR_SIZE];
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static long lastSct;
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static long lastSct;
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static Word readWord(Byte *p) {
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static Word readWord(Byte *p) {
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Word data;
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Word data;
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data = ((Word) *(p + 0)) << 24 |
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data = ((Word) *(p + 0)) << 24 |
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((Word) *(p + 1)) << 16 |
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((Word) *(p + 1)) << 16 |
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((Word) *(p + 2)) << 8 |
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((Word) *(p + 2)) << 8 |
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((Word) *(p + 3)) << 0;
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((Word) *(p + 3)) << 0;
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return data;
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return data;
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}
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}
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static void writeWord(Byte *p, Word data) {
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static void writeWord(Byte *p, Word data) {
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*(p + 0) = (Byte) (data >> 24);
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*(p + 0) = (Byte) (data >> 24);
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*(p + 1) = (Byte) (data >> 16);
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*(p + 1) = (Byte) (data >> 16);
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*(p + 2) = (Byte) (data >> 8);
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*(p + 2) = (Byte) (data >> 8);
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*(p + 3) = (Byte) (data >> 0);
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*(p + 3) = (Byte) (data >> 0);
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}
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}
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static void diskCallback(int n) {
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static void diskCallback(int n) {
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int numScts;
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int numScts;
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if (debug) {
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if (debug) {
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cPrintf("\n**** DISK CALLBACK, n = %d ****\n", n);
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cPrintf("\n**** DISK CALLBACK, n = %d ****\n", n);
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}
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}
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if (n == 0) {
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if (n == 0) {
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/* startup time expired */
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/* startup time expired */
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diskCap = totalSectors;
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diskCap = totalSectors;
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diskCtrl |= DISK_READY;
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diskCtrl |= DISK_READY;
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return;
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return;
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}
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}
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/* disk read or write */
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/* disk read or write */
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numScts = ((diskCnt - 1) & 0x07) + 1;
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numScts = ((diskCnt - 1) & 0x07) + 1;
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if (diskCap != 0 &&
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if (diskCap != 0 &&
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diskSct < diskCap &&
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diskSct < diskCap &&
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diskSct + numScts <= diskCap) {
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diskSct + numScts <= diskCap) {
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/* do the transfer */
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/* do the transfer */
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if (fseek(diskImage, diskSct * SECTOR_SIZE, SEEK_SET) != 0) {
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if (fseek(diskImage, diskSct * SECTOR_SIZE, SEEK_SET) != 0) {
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error("cannot position to sector in disk image");
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error("cannot position to sector in disk image");
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}
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}
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if (diskCtrl & DISK_WRT) {
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if (diskCtrl & DISK_WRT) {
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/* buffer --> disk */
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/* buffer --> disk */
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if (fwrite(diskBuffer, SECTOR_SIZE, numScts, diskImage) != numScts) {
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if (fwrite(diskBuffer, SECTOR_SIZE, numScts, diskImage) != numScts) {
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error("cannot write to disk image");
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error("cannot write to disk image");
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}
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}
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} else {
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} else {
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/* disk --> buffer */
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/* disk --> buffer */
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if (fread(diskBuffer, SECTOR_SIZE, numScts, diskImage) != numScts) {
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if (fread(diskBuffer, SECTOR_SIZE, numScts, diskImage) != numScts) {
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error("cannot read from disk image");
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error("cannot read from disk image");
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}
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}
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}
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}
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lastSct = (long) diskSct + (long) numScts - 1;
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lastSct = (long) diskSct + (long) numScts - 1;
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} else {
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} else {
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/* sectors requested exceed disk capacity */
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/* sectors requested exceed disk capacity */
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/* or we have no disk at all */
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/* or we have no disk at all */
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diskCtrl |= DISK_ERR;
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diskCtrl |= DISK_ERR;
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}
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}
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diskCtrl &= ~DISK_STRT;
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diskCtrl &= ~DISK_STRT;
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diskCtrl |= DISK_DONE;
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diskCtrl |= DISK_DONE;
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if (diskCtrl & DISK_IEN) {
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if (diskCtrl & DISK_IEN) {
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/* raise disk interrupt */
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/* raise disk interrupt */
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cpuSetInterrupt(IRQ_DISK);
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cpuSetInterrupt(IRQ_DISK);
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}
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}
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}
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}
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Word diskRead(Word addr) {
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Word diskRead(Word addr) {
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Word data;
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Word data;
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if (debug) {
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if (debug) {
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cPrintf("\n**** DISK READ from 0x%08X", addr);
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cPrintf("\n**** DISK READ from 0x%08X", addr);
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}
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}
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if (addr == DISK_CTRL) {
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if (addr == DISK_CTRL) {
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data = diskCtrl;
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data = diskCtrl;
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} else
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} else
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if (addr == DISK_CNT) {
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if (addr == DISK_CNT) {
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data = diskCnt;
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data = diskCnt;
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} else
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} else
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if (addr == DISK_SCT) {
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if (addr == DISK_SCT) {
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data = diskSct;
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data = diskSct;
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} else
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} else
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if (addr == DISK_CAP) {
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if (addr == DISK_CAP) {
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data = diskCap;
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data = diskCap;
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} else
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} else
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if (addr & 0x80000) {
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if (addr & 0x80000) {
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/* buffer access */
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/* buffer access */
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data = readWord(diskBuffer + (addr & 0x0FFC));
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data = readWord(diskBuffer + (addr & 0x0FFC));
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} else {
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} else {
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/* illegal register */
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/* illegal register */
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throwException(EXC_BUS_TIMEOUT);
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throwException(EXC_BUS_TIMEOUT);
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}
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}
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if (debug) {
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if (debug) {
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cPrintf(", data = 0x%08X ****\n", data);
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cPrintf(", data = 0x%08X ****\n", data);
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}
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}
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return data;
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return data;
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}
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}
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void diskWrite(Word addr, Word data) {
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void diskWrite(Word addr, Word data) {
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long delta;
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long delta;
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if (debug) {
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if (debug) {
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cPrintf("\n**** DISK WRITE to 0x%08X, data = 0x%08X ****\n",
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cPrintf("\n**** DISK WRITE to 0x%08X, data = 0x%08X ****\n",
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addr, data);
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addr, data);
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}
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}
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if (addr == DISK_CTRL) {
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if (addr == DISK_CTRL) {
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if (data & DISK_WRT) {
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if (data & DISK_WRT) {
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diskCtrl |= DISK_WRT;
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diskCtrl |= DISK_WRT;
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} else {
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} else {
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diskCtrl &= ~DISK_WRT;
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diskCtrl &= ~DISK_WRT;
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}
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}
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if (data & DISK_IEN) {
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if (data & DISK_IEN) {
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diskCtrl |= DISK_IEN;
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diskCtrl |= DISK_IEN;
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} else {
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} else {
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diskCtrl &= ~DISK_IEN;
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diskCtrl &= ~DISK_IEN;
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}
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}
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if (data & DISK_STRT) {
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if (data & DISK_STRT) {
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diskCtrl |= DISK_STRT;
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diskCtrl |= DISK_STRT;
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diskCtrl &= ~DISK_ERR;
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diskCtrl &= ~DISK_ERR;
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diskCtrl &= ~DISK_DONE;
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diskCtrl &= ~DISK_DONE;
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/* only start a disk operation if disk is present */
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/* only start a disk operation if disk is present */
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if (diskCap != 0) {
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if (diskCap != 0) {
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delta = labs((long) diskSct - lastSct);
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delta = labs((long) diskSct - lastSct);
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if (delta > diskCap) {
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if (delta > diskCap) {
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delta = diskCap;
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delta = diskCap;
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}
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}
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timerStart(DISK_DELAY + (delta * DISK_SEEK) / diskCap,
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timerStart(DISK_DELAY_USEC + (delta * DISK_SEEK_USEC) / diskCap,
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diskCallback, 1);
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diskCallback, 1);
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}
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}
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} else {
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} else {
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diskCtrl &= ~DISK_STRT;
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diskCtrl &= ~DISK_STRT;
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if (data & DISK_ERR) {
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if (data & DISK_ERR) {
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diskCtrl |= DISK_ERR;
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diskCtrl |= DISK_ERR;
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} else {
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} else {
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diskCtrl &= ~DISK_ERR;
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diskCtrl &= ~DISK_ERR;
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}
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}
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if (data & DISK_DONE) {
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if (data & DISK_DONE) {
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diskCtrl |= DISK_DONE;
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diskCtrl |= DISK_DONE;
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} else {
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} else {
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diskCtrl &= ~DISK_DONE;
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diskCtrl &= ~DISK_DONE;
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}
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}
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}
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}
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if ((diskCtrl & DISK_IEN) != 0 &&
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if ((diskCtrl & DISK_IEN) != 0 &&
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(diskCtrl & DISK_DONE) != 0) {
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(diskCtrl & DISK_DONE) != 0) {
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/* raise disk interrupt */
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/* raise disk interrupt */
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cpuSetInterrupt(IRQ_DISK);
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cpuSetInterrupt(IRQ_DISK);
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} else {
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} else {
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/* lower disk interrupt */
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/* lower disk interrupt */
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cpuResetInterrupt(IRQ_DISK);
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cpuResetInterrupt(IRQ_DISK);
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}
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}
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} else
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} else
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if (addr == DISK_CNT) {
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if (addr == DISK_CNT) {
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diskCnt = data;
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diskCnt = data;
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} else
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} else
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if (addr == DISK_SCT) {
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if (addr == DISK_SCT) {
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diskSct = data;
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diskSct = data;
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} else
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} else
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if (addr == DISK_CAP) {
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if (addr == DISK_CAP) {
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/* this register is read-only */
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/* this register is read-only */
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throwException(EXC_BUS_TIMEOUT);
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throwException(EXC_BUS_TIMEOUT);
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} else
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} else
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if (addr & 0x80000) {
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if (addr & 0x80000) {
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/* buffer access */
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/* buffer access */
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writeWord(diskBuffer + (addr & 0x0FFC), data);
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writeWord(diskBuffer + (addr & 0x0FFC), data);
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} else {
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} else {
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/* illegal register */
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/* illegal register */
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throwException(EXC_BUS_TIMEOUT);
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throwException(EXC_BUS_TIMEOUT);
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}
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}
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}
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}
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void diskReset(void) {
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void diskReset(void) {
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cPrintf("Resetting Disk...\n");
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cPrintf("Resetting Disk...\n");
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diskCtrl = 0;
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diskCtrl = 0;
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diskCnt = 0;
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diskCnt = 0;
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diskSct = 0;
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diskSct = 0;
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diskCap = 0;
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diskCap = 0;
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lastSct = 0;
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lastSct = 0;
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if (totalSectors != 0) {
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if (totalSectors != 0) {
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cPrintf("Disk of size %ld sectors (%ld bytes) installed.\n",
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cPrintf("Disk of size %ld sectors (%ld bytes) installed.\n",
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totalSectors, totalSectors * SECTOR_SIZE);
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totalSectors, totalSectors * SECTOR_SIZE);
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timerStart(DISK_STARTUP, diskCallback, 0);
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timerStart(DISK_START_USEC, diskCallback, 0);
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}
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}
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}
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}
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void diskInit(char *diskImageName) {
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void diskInit(char *diskImageName) {
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long numBytes;
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long numBytes;
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if (diskImageName == NULL) {
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if (diskImageName == NULL) {
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/* do not install disk */
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/* do not install disk */
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diskImage = NULL;
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diskImage = NULL;
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totalSectors = 0;
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totalSectors = 0;
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} else {
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} else {
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/* try to install disk */
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/* try to install disk */
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diskImage = fopen(diskImageName, "r+b");
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diskImage = fopen(diskImageName, "r+b");
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if (diskImage == NULL) {
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if (diskImage == NULL) {
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error("cannot open disk image '%s'", diskImageName);
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error("cannot open disk image '%s'", diskImageName);
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}
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}
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fseek(diskImage, 0, SEEK_END);
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fseek(diskImage, 0, SEEK_END);
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numBytes = ftell(diskImage);
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numBytes = ftell(diskImage);
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fseek(diskImage, 0, SEEK_SET);
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fseek(diskImage, 0, SEEK_SET);
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if (numBytes % SECTOR_SIZE != 0) {
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if (numBytes % SECTOR_SIZE != 0) {
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error("disk image '%s' does not contain an integral number of sectors",
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error("disk image '%s' does not contain an integral number of sectors",
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diskImageName);
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diskImageName);
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}
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}
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totalSectors = numBytes / SECTOR_SIZE;
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totalSectors = numBytes / SECTOR_SIZE;
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}
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}
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diskReset();
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diskReset();
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}
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}
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void diskExit(void) {
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void diskExit(void) {
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if (diskImage == NULL) {
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if (diskImage == NULL) {
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/* disk not installed */
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/* disk not installed */
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return;
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return;
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}
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}
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fclose(diskImage);
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fclose(diskImage);
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}
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}
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