MacIIROMDiskDriver/rdisk.c
2021-06-09 19:15:40 -04:00

355 lines
11 KiB
C

#include <Memory.h>
#include <Devices.h>
#include <Files.h>
#include <Disks.h>
#include <Errors.h>
#include <Events.h>
#include <OSUtils.h>
#include "rdisk.h"
// Decode keyboard/PRAM settings
static void RDDecodeSettings(Ptr unmountEN, Ptr mountEN, Ptr ramEN, Ptr dbgEN, Ptr cdrEN) {
// Sample R and A keys repeatedly
char r = 0, a = 0;
long tmax = TickCount() + 60;
for (long i = 0; i < 1000000; i++) {
r |= RDiskIsRPressed();
a |= RDiskIsAPressed();
if (r && a) { break; }
if (TickCount() > tmax) { break; }
}
// Read PRAM
char legacy_startup, legacy_ram;
RDiskReadXPRAM(1, 4, &legacy_startup);
RDiskReadXPRAM(1, 5, &legacy_ram);
// Decode settings: unmount (don't boot), mount (after boot), RAM disk
if (r) { // R boots from ROM disk
*unmountEN = 0; // Don't unmount so we boot from this drive
*mountEN = 0; // No need to mount later since we are boot disk
*ramEN = a; // A enables RAM disk
*dbgEN = 0;
*cdrEN = 1;
} else {
if (legacy_startup & 0x01) { // Boot from ROM disk
*unmountEN = 0; // Don't unmount so we boot from this drive
*mountEN = 0; // No need to mount later since we are boot disk
*ramEN = legacy_ram & 0x01; // Allocate RAM disk if bit 0 == 1
*dbgEN = legacy_startup & 0x04; // MacsBug enabled if bit 2 == 1
*cdrEN = !(legacy_startup & 0x08); // CD-ROM enabled if bit 3 == 0
} else if (legacy_startup & 0x02) { // Mount ROM disk
*unmountEN = 1; // Unmount to not boot from our disk
*mountEN = 1; // Mount in accRun
*ramEN = legacy_ram & 0x01; // Allocate RAM disk if bit 0 == 1
*dbgEN = 1; // CD-ROM ext. always enabled in mount mode
*cdrEN = 1; // MacsBug always enabled in mount mode
} else {
*unmountEN = 1; // Unmount
*mountEN = 0; // Don't mount again
*ramEN = 0; // Don't allocate RAM disk
*dbgEN = 1; // CD-ROM ext. always enabled in unmount mode
*cdrEN = 1; // MacsBug always enabled in unmount mode
}
}
}
// Switch to 32-bit mode and copy
#pragma parameter C24(__A0, __A1, __D0)
void __attribute__ ((noinline)) C24(Ptr sourcePtr, Ptr destPtr, unsigned long byteCount) {
signed char mode = true32b;
SwapMMUMode(&mode);
BlockMove(sourcePtr, destPtr, byteCount);
SwapMMUMode(&mode);
}
// Switch to 32-bit mode and get
#pragma parameter __D0 G24(__A2)
char __attribute__ ((noinline)) G24(Ptr pos) {
long ret;
signed char mode = true32b;
SwapMMUMode(&mode);
ret = *pos; // Peek
SwapMMUMode(&mode);
return ret;
}
// Switch to 32-bit mode and set
#pragma parameter S24(__A2, __D3)
void __attribute__ ((noinline)) S24(Ptr pos, char patch) {
signed char mode = true32b;
SwapMMUMode(&mode);
*pos = patch; // Poke
SwapMMUMode(&mode);
}
// Figure out the first available drive number >= 5
static int RDFindDrvNum() {
DrvQElPtr dq;
int drvNum = 5;
for (dq = (DrvQElPtr)(GetDrvQHdr())->qHead; dq; dq = (DrvQElPtr)dq->qLink) {
if (dq->dQDrive >= drvNum) { drvNum = dq->dQDrive + 1; }
}
return drvNum;
}
#pragma parameter __D0 RDOpen(__A0, __A1)
OSErr RDOpen(IOParamPtr p, DCtlPtr d) {
int drvNum;
RDiskStorage_t *c;
char legacy_startup;
// Do nothing if already opened
if (d->dCtlStorage) { return noErr; }
// Do nothing if inhibited
RDiskReadXPRAM(1, 4, &legacy_startup);
if (legacy_startup & 0x80) { return noErr; }
// Allocate storage struct
d->dCtlStorage = NewHandleSysClear(sizeof(RDiskStorage_t));
if (!d->dCtlStorage) { return openErr; }
// Lock our storage struct and get master pointer
HLock(d->dCtlStorage);
c = *(RDiskStorage_t**)d->dCtlStorage;
// Find first available drive number
drvNum = RDFindDrvNum();
// Set drive status
//c->status.track = 0;
c->status.writeProt = -1; // nonzero is write protected
c->status.diskInPlace = 8; // 8 is nonejectable disk
c->status.installed = 1; // drive installed
//c->status.sides = 0;
//c->status.qType = 1;
c->status.dQDrive = drvNum;
//c->status.dQFSID = 0;
c->status.dQRefNum = d->dCtlRefNum;
c->status.driveSize = RDiskSize / 512;
//c->status.driveS1 = (RDiskSize / 512) >> 16;
// Decompress icon
#ifdef RDISK_COMPRESS_ICON_ENABLE
char *src = &RDiskIconCompressed[0];
char *dst = &c->icon[0];
UnpackBits(&src, &dst, RDISK_ICON_SIZE);
#endif
// Add drive to drive queue and return
RDiskAddDrive(c->status.dQRefNum, drvNum, (DrvQElPtr)&c->status.qLink);
return noErr;
}
// Init is called at beginning of first prime (read/write) call
static void RDInit(IOParamPtr p, DCtlPtr d, RDiskStorage_t *c) {
char unmountEN, mountEN, ramEN, dbgEN, cdrEN;
// Mark init done
c->initialized = 1;
// Decode settings
RDDecodeSettings(&unmountEN, &mountEN, &ramEN, &dbgEN, &cdrEN);
// If RAM disk enabled, try to allocate RAM disk buffer if not already
if (ramEN & !c->ramdisk) {
if (*MMU32bit) { // 32-bit mode
unsigned long minBufPtr, newBufPtr;
// Compute if there is enough high memory
minBufPtr = ((unsigned long)*MemTop / 2) + 1024;
newBufPtr = (unsigned long)*BufPtr - RDiskSize;
if (newBufPtr > minBufPtr && (unsigned long)*BufPtr > newBufPtr) {
// Allocate RAM disk buffer by lowering BufPtr
*BufPtr = (Ptr)newBufPtr;
// Set RAM disk buffer pointer.
c->ramdisk = *BufPtr;
// Copy ROM disk image to RAM disk
BlockMove(RDiskBuf, c->ramdisk, RDiskSize);
// Clearing write protect marks RAM disk enabled
c->status.writeProt = 0;
}
} else { // 24-bit mode
// Put RAM disk just past 8MB
c->ramdisk = (Ptr)(8 * 1024 * 1024);
// Copy ROM disk image to RAM disk
//FIXME: what if we don't have enough RAM?
// Will this wrap around and overwrite low memory?
// That's not the worst, since the system would just crash,
// but it would be better to switch to read-only status
copy24(RDiskBuf, c->ramdisk, RDiskSize);
// Clearing write protect marks RAM disk enabled
c->status.writeProt = 0;
}
}
// Get debug and CD-ROM disable settings from ROM table
c->dbgDisPos = *(long*)0x40851D98;
c->cdrDisPos = *(long*)0x40851D9C;
c->dbgDisByte = *(char*)0x40851DA8;
c->cdrDisByte = *(char*)0x40851DA9;
// Patch
if (c->dbgDisPos < RDiskSize) {
if (c->ramdisk && !dbgEN) {
poke24(c->ramdisk + c->dbgDisPos, c->dbgDisByte);
} else if (dbgEN) {
peek24(RDiskBuf + c->dbgDisPos, c->dbgDisByte);
}
}
if (c->cdrDisPos < RDiskSize) {
if (c->ramdisk && !cdrEN) {
poke24(c->ramdisk + c->cdrDisPos, c->cdrDisByte);
} else if (cdrEN) {
peek24(RDiskBuf + c->cdrDisPos, c->cdrDisByte);
}
}
// Unmount if not booting from ROM disk
if (unmountEN) { c->status.diskInPlace = 0; }
// If mount enabled, enable accRun to post disk inserted event later
if (mountEN) {
d->dCtlDelay = 150; // Set accRun delay (150 ticks is 2.5 sec.)
d->dCtlFlags |= dNeedTimeMask; // Enable accRun
}
}
#pragma parameter __D0 RDPrime(__A0, __A1)
OSErr RDPrime(IOParamPtr p, DCtlPtr d) {
RDiskStorage_t *c;
char cmd;
Ptr disk;
// Return disk offline error if dCtlStorage null
if (!d->dCtlStorage) { return notOpenErr; }
// Dereference dCtlStorage to get pointer to our context
c = *(RDiskStorage_t**)d->dCtlStorage;
// Initialize if this is the first prime call
if (!c->initialized) { RDInit(p, d, c); }
// Return disk offline error if virtual disk not inserted
if (!c->status.diskInPlace) { return offLinErr; }
// Get pointer to RAM or ROM disk buffer
disk = (c->ramdisk ? c->ramdisk : RDiskBuf) + d->dCtlPosition;
// Bounds checking
if (d->dCtlPosition >= RDiskSize || p->ioReqCount >= RDiskSize ||
d->dCtlPosition + p->ioReqCount >= RDiskSize) { return paramErr; }
// Service read or write request
cmd = p->ioTrap & 0x00FF;
if (cmd == aRdCmd) { // Read
// Read from disk into buffer.
if (*MMU32bit) { BlockMove(disk, p->ioBuffer, p->ioReqCount); }
else { copy24(disk, StripAddress(p->ioBuffer), p->ioReqCount); }
if (!c->ramdisk && c->dbgDisPos >= d->dCtlPosition &&
c->dbgDisPos < d->dCtlPosition + p->ioReqCount) {
p->ioBuffer[c->dbgDisPos - d->dCtlPosition] = c->dbgDisByte;
}
if (!c->ramdisk && c->cdrDisPos >= d->dCtlPosition &&
c->cdrDisPos < d->dCtlPosition + p->ioReqCount) {
p->ioBuffer[c->cdrDisPos - d->dCtlPosition] = c->cdrDisByte;
}
} else if (cmd == aWrCmd) { // Write
// Fail if write protected or RAM disk buffer not set up
if (c->status.writeProt || !c->ramdisk) { return wPrErr; }
// Write from buffer into disk.
if (*MMU32bit) { BlockMove(p->ioBuffer, disk, p->ioReqCount); }
else { copy24(StripAddress(p->ioBuffer), disk, p->ioReqCount); }
} else { return noErr; } //FIXME: Fail if cmd isn't read or write?
// Update count and position/offset, then return
d->dCtlPosition += p->ioReqCount;
p->ioActCount = p->ioReqCount;
return noErr;
}
#pragma parameter __D0 RDCtl(__A0, __A1)
OSErr RDCtl(CntrlParamPtr p, DCtlPtr d) {
RDiskStorage_t *c;
// Fail if dCtlStorage null
if (!d->dCtlStorage) { return notOpenErr; }
// Dereference dCtlStorage to get pointer to our context
c = *(RDiskStorage_t**)d->dCtlStorage;
// Handle control request based on csCode
switch (p->csCode) {
case killCode:
return noErr;
case kFormat:
if (!c->status.diskInPlace || c->status.writeProt ||
!c->ramdisk) { return controlErr; }
long long z = 0;
Ptr pz;
if (*MMU32bit) { pz = (Ptr)&z; }
else { pz = StripAddress((Ptr)&z); }
for (int i = 0; i < 4095; i++) {
copy24(c->ramdisk + i * sizeof(z), pz, sizeof(z));
}
return noErr;
case kVerify:
if (!c->status.diskInPlace) { return controlErr; }
return noErr;
case kEject:
// "Reinsert" disk if ejected illegally
if (c->status.diskInPlace) {
PostEvent(diskEvt, c->status.dQDrive);
}
return controlErr; // Eject not allowed so return error
case accRun:
d->dCtlFlags &= ~dNeedTimeMask; // Disable accRun
c->status.diskInPlace = 8; // 8 is nonejectable disk
PostEvent(diskEvt, c->status.dQDrive); // Post disk inserted event
return noErr;
case kDriveIcon: case kMediaIcon: // Get icon
#ifdef RDISK_COMPRESS_ICON_ENABLE
*(Ptr*)p->csParam = (Ptr)c->icon;
#else
*(Ptr*)p->csParam = (Ptr)RDiskIcon;
#endif
return noErr;
case kDriveInfo:
// high word (bytes 2 & 3) clear
// byte 1 = primary + fixed media + internal
// byte 0 = drive type (0x10 is RAM disk) / (0x11 is ROM disk)
if (c->status.writeProt) { *(long*)p->csParam = 0x00000411; }
else { *(long*)p->csParam = 0x00000410; }
return noErr;
case 24: // Return SCSI partition size
*(long*)p->csParam = RDiskSize / 512;
return noErr;
case 2351: // Post-boot
c->initialized = 1; // Skip initialization
d->dCtlDelay = 30; // Set accRun delay (30 ticks is 0.5 sec.)
d->dCtlFlags |= dNeedTimeMask; // Enable accRun
return noErr;
default: return controlErr;
}
}
#pragma parameter __D0 RDStat(__A0, __A1)
OSErr RDStat(CntrlParamPtr p, DCtlPtr d) {
//RDiskStorage_t *c;
// Fail if dCtlStorage null
if (!d->dCtlStorage) { return notOpenErr; }
// Dereference dCtlStorage to get pointer to our context
//c = *(RDiskStorage_t**)d->dCtlStorage;
// Handle status request based on csCode
switch (p->csCode) {
case kDriveStatus:
BlockMove(*d->dCtlStorage, &p->csParam, sizeof(DrvSts2));
return noErr;
default: return statusErr;
}
}
#pragma parameter __D0 RDClose(__A0, __A1)
OSErr RDClose(IOParamPtr p, DCtlPtr d) {
// If dCtlStorage not null, dispose of it
if (!d->dCtlStorage) { return noErr; }
//RDiskStorage_t *c = *(RDiskStorage_t**)d->dCtlStorage;
HUnlock(d->dCtlStorage);
DisposeHandle(d->dCtlStorage);
d->dCtlStorage = NULL;
return noErr;
}