MacIIROMDiskDriver/rdisk.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"

#ifdef RDISK_COMPRESS_ICON
#include <Quickdraw.h>
const char const RDiskIconCompressed[92] = {
	-1 * (76 - 1), 0b00000000, /*
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000, */
	-1 * (4 - 1), 0b11111111, /*
	0b11111111, 0b11111111, 0b11111111, 0b11111111, */
	(40 - 1),
	0b11111111, 0b11111111, 0b11111111, 0b11111111,
	0b10000000, 0b00000000, 0b00000000, 0b00000001,
	0b10001111, 0b00011110, 0b00111100, 0b01111001,
	0b10001001, 0b00010010, 0b00100100, 0b01001001,
	0b10001001, 0b00010010, 0b00100100, 0b01001001,
	0b10001001, 0b00010010, 0b00100100, 0b01001001,
	0b10001111, 0b00011110, 0b00111100, 0b01111001,
	0b11000000, 0b00000000, 0b00000000, 0b00000001,
	0b01010101, 0b01010101, 0b11010101, 0b01010101,
	0b01111111, 0b11111111, 0b01111111, 0b11111111,
	-1 * (12 - 1), 0b00000000, /*
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000, */
	
	-1 * (76 - 1), 0b00000000, /*
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000, */
	-1 * (32 - 1), 0b11111111, /*
	0b11111111, 0b11111111, 0b11111111, 0b11111111,
	0b11111111, 0b11111111, 0b11111111, 0b11111111,
	0b11111111, 0b11111111, 0b11111111, 0b11111111,
	0b11111111, 0b11111111, 0b11111111, 0b11111111,
	0b11111111, 0b11111111, 0b11111111, 0b11111111,
	0b11111111, 0b11111111, 0b11111111, 0b11111111,
	0b11111111, 0b11111111, 0b11111111, 0b11111111,
	0b11111111, 0b11111111, 0b11111111, 0b11111111, */
	(8 - 1),
	0b01111111, 0b11111111, 0b11111111, 0b11111111,
	0b01111111, 0b11111111, 0b11111111, 0b11111111,
	-1 * (12 - 1), 0b00000000, /*
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000, */
	(29 - 1),
	27, 'G', 'a', 'r', 'r', 'e', 't', 't', '\'', 's', ' ', 
	'W', 'o', 'r', 'k', 's', 'h', 'o', 'p', ' ', 
	'R', 'O', 'M', ' ', 'D', 'i', 's', 'k', 0
};
#else
const char const RDiskIcon[285] = {
	// Icon
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b11111111, 0b11111111, 0b11111111, 0b11111111,
	0b10000000, 0b00000000, 0b00000000, 0b00000001,
	0b10001111, 0b00011110, 0b00111100, 0b01111001,
	0b10001001, 0b00010010, 0b00100100, 0b01001001,
	0b10001001, 0b00010010, 0b00100100, 0b01001001,
	0b10001001, 0b00010010, 0b00100100, 0b01001001,
	0b10001111, 0b00011110, 0b00111100, 0b01111001,
	0b11000000, 0b00000000, 0b00000000, 0b00000001,
	0b01010101, 0b01010101, 0b11010101, 0b01010101,
	0b01111111, 0b11111111, 0b01111111, 0b11111111,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	// Mask
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b11111111, 0b11111111, 0b11111111, 0b11111111,
	0b11111111, 0b11111111, 0b11111111, 0b11111111,
	0b11111111, 0b11111111, 0b11111111, 0b11111111,
	0b11111111, 0b11111111, 0b11111111, 0b11111111,
	0b11111111, 0b11111111, 0b11111111, 0b11111111,
	0b11111111, 0b11111111, 0b11111111, 0b11111111,
	0b11111111, 0b11111111, 0b11111111, 0b11111111,
	0b11111111, 0b11111111, 0b11111111, 0b11111111,
	0b01111111, 0b11111111, 0b11111111, 0b11111111,
	0b01111111, 0b11111111, 0b11111111, 0b11111111,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	0b00000000, 0b00000000, 0b00000000, 0b00000000,
	27, 'G', 'a', 'r', 'r', 'e', 't', 't', '\'', 's', ' ', 
	'W', 'o', 'r', 'k', 's', 'h', 'o', 'p', ' ', 
	'R', 'O', 'M', ' ', 'D', 'i', 's', 'k', 0
};
#endif

static void RDiskDecodeSettings(RDiskStorage_t *c, Ptr unmount, Ptr mount, Ptr ram) {
	// Decode settings
	if (c->postBoot) {
		*unmount = 0;
		*mount = 1;
		*ram = 0;
	} else if (RDiskIsRPressed()) { // R boots from ROM disk
		*unmount = 0;
		*mount = 0;
		*ram = RDiskIsAPressed(); // A enables RAM disk
	} else {
		// Read PRAM
		char legacy_startup, legacy_ram;
		RDiskReadXPRAM(1, 4, &legacy_startup);
		RDiskReadXPRAM(1, 5, &legacy_ram);
		if (legacy_startup == 1) {
			*unmount = 0;
			*mount = 0;
			*ram = legacy_ram;
		} else if (legacy_startup == 2 || legacy_startup == 3 || 
				   legacy_startup == 4 || legacy_startup == 5 || 
				   legacy_startup == 6 || legacy_startup == 7) {
			*unmount = 1;
			*mount = 1;
			*ram = legacy_ram & 1;
		} else {
			*unmount = 1;
			*mount = 0;
			*ram = 0;
		}
	}
}

// Switch to 24-bit mode and copy
void RDiskCopy24(Ptr sourcePtr, Ptr destPtr, unsigned long byteCount) {
	char mode = true32b;
	SwapMMUMode(&mode);
	BlockMove(sourcePtr, destPtr, byteCount);
	SwapMMUMode(&mode);
}

// Figure out the first available drive number >= 5
static int RDiskFindDrvNum() {
	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 RDiskOpen(__A0, __A1)
OSErr RDiskOpen(IOParamPtr p, DCtlPtr d) {
	int drvNum;
	RDiskStorage_t *c;
	char legacy_startup, legacy_ram;

	// Do nothing if already opened
	if (d->dCtlStorage) { 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 = RDiskFindDrvNum();

	// 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; // drive installed
	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;

	#ifdef RDISK_COMPRESS_ICON
	// Decompress icon
	char *src = &RDiskIconCompressed[0];
	char *dst = &c->icon[0];
	UnpackBits(&src, &dst, 285);
	#endif

	// Add drive to drive queue and return
	RDiskAddDrive(c->status.dQRefNum, drvNum, (DrvQElPtr)&c->status.qLink);
	return noErr;
}

static void RDiskInit(IOParamPtr p, DCtlPtr d, RDiskStorage_t *c) {
	char unmountEN, mountEN, ramEN;

	// Mark init done
	c->initialized = 1;

	// Decode settings
	RDiskDecodeSettings(c, &unmountEN, &mountEN, &ramEN);

	// 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
			// Get address of copy24 routine 
			RDiskCopy_t copy24 = (RDiskCopy_t)RDiskCopy24;
			// Put RAM disk just past 8MB
			c->ramdisk = (Ptr)(8 * 1024 * 1024);
			// Copy ROM disk image to RAM disk
			copy24(RDiskBuf, c->ramdisk, RDiskSize);
			// Clearing write protect marks RAM disk enabled
			c->status.writeProt = 0;
			//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
		}
	}

	// Unmount if not booting from ROM disk
	if (unmountEN) {
		c->status.diskInPlace = 0; // 0 == no disk in drive
	}

	// If mount enabled, enable accRun to post disk inserted event later
	if (mountEN) { 
		d->dCtlFlags |= dNeedTimeMask; // Enable accRun
		d->dCtlDelay = 150; // Set accRun delay (150 ticks is 2.5 sec.)
	}
}

#pragma parameter __D0 RDiskPrime(__A0, __A1)
OSErr RDiskPrime(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) { RDiskInit(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 { 
			// Get address of copy24 routine and then copy
			RDiskCopy_t copy24 = (RDiskCopy_t)RDiskCopy24;
			copy24(disk, StripAddress(p->ioBuffer), p->ioReqCount);
		}
	} 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 { 
			// Get address of copy24 routine and then copy
			RDiskCopy_t copy24 = (RDiskCopy_t)RDiskCopy24;
			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 RDiskControl(__A0, __A1)
OSErr RDiskControl(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 kFormat:
			if (!c->status.diskInPlace || c->status.writeProt || !c->ramdisk) {
				return controlErr;
			} 
			long zero[16];
			zero[0] = 0;
			for (int i = 0; i < 256; i++) {
				if (*MMU32bit) { BlockMove(zero, c->ramdisk, sizeof(zero)); }
				else { 
					// Get address of copy24 routine and then copy
					RDiskCopy_t copy24 = (RDiskCopy_t)RDiskCopy24;
					copy24((Ptr)zero, c->ramdisk, sizeof(zero));
				}
			}
			return noErr;
		case kVerify:
			if (!c->status.diskInPlace) { return controlErr; }
			return noErr;
		case killCode:
			return noErr;
		case kEject:
			// "Reinsert" disk if ejected illegally
			if (c->installed) { 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
			*(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 = 0x00000410; }
			else { *(long*)p->csParam = 0x00000411; }
			return noErr;
		case 24: // Return SCSI partition size
			*(long*)p->csParam = RDiskSize / 512;
			return noErr;
		case 2351: // Enable post-boot mode
			c->postBoot = 1;
			return noErr;
		default: return controlErr;
	}
}

#pragma parameter __D0 RDiskStatus(__A0, __A1)
OSErr RDiskStatus(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 RDiskClose(__A0, __A1)
OSErr RDiskClose(IOParamPtr p, DCtlPtr d) {
	// If dCtlStorage not null, dispose of it and its contents
	if (!d->dCtlStorage) { return noErr; }
	RDiskStorage_t *c = *(RDiskStorage_t**)d->dCtlStorage;
	HUnlock(d->dCtlStorage);
	DisposeHandle(d->dCtlStorage);
	d->dCtlStorage = NULL;
	return noErr;
}