MacIIROMDiskDriver/rdisk.c
2020-06-26 05:21:49 -04:00

296 lines
9.3 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"
// Switch to 24-bit mode and copy. Call this with
// PC==0x408XXXXX, not PC==0x008XXXXX
void RDiskCopy24(char *sourcePtr, char *destPtr, unsigned long byteCount) {
char mode = true32b;
SwapMMUMode(&mode);
BlockMove(sourcePtr, destPtr, byteCount);
SwapMMUMode(&mode);
}
typedef struct RDiskStorage_s {
DrvSts2 drvsts;
unsigned long init_done;
char *ramdisk;
Ptr ramdisk_alloc;
char ramdisk_valid;
} RDiskStorage_t;
#pragma parameter __D0 RDiskOpen(__A0, __A1)
OSErr RDiskOpen(IOParamPtr p, DCtlPtr d) {
DrvQElPtr dq;
DrvSts2 *status;
int drvNum;
RDiskStorage_t *c;
// Do nothing if already opened
if (d->dCtlStorage) { return noErr; }
// Figure out first available drive number
drvNum = 1;
for (dq = (DrvQElPtr)(GetDrvQHdr())->qHead; dq; dq = (DrvQElPtr)dq->qLink) {
if (dq->dQDrive >= drvNum) { drvNum = dq->dQDrive + 1; }
}
// 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;
// Initialize storage struct fields
c->init_done = 0;
c->ramdisk = NULL;
c->ramdisk_alloc = NULL;
c->ramdisk_valid = 0;
// Set drive status
status = &c->drvsts;
status->writeProt = 0xF0;
status->diskInPlace = 0x08;
status->dQDrive = drvNum;
status->dQRefNum = d->dCtlRefNum;
status->driveSize = (RDiskSize / 512) & 0xFFFF;
status->driveS1 = ((RDiskSize / 512) & 0xFFFF0000) >> 16;
// Set driver flags?
/* d->dCtlFlags |= dReadEnableMask | dWritEnableMask |
dCtlEnableMask | dStatEnableMask |
dNeedLockMask; // 0x4F */
// Add drive to drive queue and return
RDiskAddDrive(status->dQRefNum, drvNum, (DrvQElPtr)&status->qLink);
return noErr;
}
OSErr RDiskInit(IOParamPtr p, DCtlPtr d, RDiskStorage_t *c) {
char startup = 0, ram = 0;
// Mark init done
c->init_done = 1;
// Read PRAM
RDiskReadXPRAM(1, 4, &startup);
RDiskReadXPRAM(1, 5, &ram);
// Either enable ROM disk or remove ourselves from the drive queue
if (startup || RDiskIsRPressed()) { // If ROM disk boot set in PRAM or R pressed,*/
// Set ROM disk attributes
c->drvsts.writeProt = -1; // Set write protected
// Clear disk fields (even though we used NewHandleSysClear)
c->ramdisk = NULL;
c->ramdisk_alloc = NULL;
c->ramdisk_valid = 0;
// If RAM disk set in PRAM or A pressed, enable RAM disk
if (ram || RDiskIsAPressed()) {
unsigned long minBufPtr, newBufPtr;
// Clearing write protect marks RAM disk enabled
c->drvsts.writeProt = 0;
// Compute if there is enough high memory
minBufPtr = ((unsigned long)*MemTop / 2) + 1024;
newBufPtr = (unsigned long)*BufPtr - RDiskSize;
// If in 32-bit mode and there is enough high memory, set ramdisk pointer now
if (*MMU32bit & newBufPtr > minBufPtr && (unsigned long)*BufPtr > newBufPtr) {
// Allocate RAM disk buffer by lowering BufPtr
*BufPtr = (Ptr)newBufPtr;
// Set RAM disk buffer pointer. Defer copying until accRun
// Don't set ramdisk_alloc because there is nothing to free.
c->ramdisk = *BufPtr;
// Copy ROM disk image to RAM disk
BlockMove(RDiskBuf, c->ramdisk, RDiskSize);
c->ramdisk_valid = 1;
} else {
// Enable accRun to allocate and copy later
d->dCtlFlags |= dNeedTimeMask;
d->dCtlDelay = 0x10;
}
}
return noErr;
} else { // Otherwise if R not held down and ROM boot not set in PRAM,
// Remove our driver from the drive queue
DrvQElPtr dq;
QHdrPtr QHead = DrvQHdr;
// Loop through entire drive queue, searching for our device or stopping at the end.
dq = (DrvQElPtr)QHead->qHead;
while ((dq != (DrvQElPtr)(QHead->qTail)) &&
(dq->dQRefNum != d->dCtlRefNum)) {
dq = (DrvQElPtr)(dq->qLink);
}
// If we found our driver, remove it from the queue
if (dq->dQRefNum == d->dCtlRefNum) {
Dequeue((QElemPtr)dq, QHead);
if (c->ramdisk_alloc) { DisposePtr(c->ramdisk_alloc); }
DisposeHandle(d->dCtlStorage);
}
d->dCtlStorage = NULL;
// Return disk offline error
return offLinErr;
}
}
#pragma parameter __D0 RDiskPrime(__A0, __A1)
OSErr RDiskPrime(IOParamPtr p, DCtlPtr d) {
RDiskStorage_t *c;
char cmd;
char *disk;
long offset;
RDiskCopy_t copy24 = &RDiskCopy24;
// Return disk offline error if dCtlStorage null
if (!d->dCtlStorage) { return offLinErr; }
// Dereference dCtlStorage to get pointer to our context
c = *(RDiskStorage_t**)d->dCtlStorage;
// Initialize if this is the first prime call
if (!c->init_done) {
OSErr ret = RDiskInit(p, d, c);
if (ret != noErr) { return ret; }
}
// Get pointer to RAM or ROM disk buffer
disk = c->ramdisk && c->ramdisk_valid ? c->ramdisk : RDiskBuf;
// Add offset to buffer pointer according to positioning mode
switch (p->ioPosMode & 0x000F) {
case fsAtMark: offset = d->dCtlPosition; break;
case fsFromStart: offset = p->ioPosOffset; break;
case fsFromMark: offset = d->dCtlPosition + p->ioPosOffset; break;
default: break;
}
disk += offset;
// Bounds checking
/*if (offset >= RDiskSize || p->ioReqCount >= RDiskSize ||
offset + p->ioReqCount >= RDiskSize ||
disk + offset < disk) { return posErr; }*/
// Service read or write request
cmd = p->ioTrap & 0x00FF;
if (cmd == aRdCmd) { // Read
// Return immediately if verify operation requested
//FIXME: follow either old (verify) or new (read uncached) convention
/*if (p->ioPosMode & rdVerifyMask) {
return noErr;
}*/
// Read from disk into buffer.
if (*MMU32bit) { BlockMove(disk, p->ioBuffer, p->ioReqCount); }
else { // 24-bit addressing
char *buffer = (char*)Translate24To32(StripAddress(p->ioBuffer));
copy24(disk, buffer, p->ioReqCount);
}
// Update count
p->ioActCount = p->ioReqCount;
d->dCtlPosition = offset + p->ioReqCount;
p->ioPosOffset = d->dCtlPosition;
return noErr;
} else if (cmd == aWrCmd) { // Write
// Fail if write protected or RAM disk buffer not set up
if (c->drvsts.writeProt || !c->ramdisk || !c->ramdisk_valid) { return wPrErr; }
// Write from buffer into disk.
if (*MMU32bit) { BlockMove((char*)p->ioBuffer, disk, p->ioReqCount); }
else { // 24-bit addressing
char *buffer = (char*)Translate24To32(StripAddress(p->ioBuffer));
copy24(buffer, disk, p->ioReqCount);
}
// Update count and position/offset
p->ioActCount = p->ioReqCount;
d->dCtlPosition = offset + p->ioReqCount;
p->ioPosOffset = d->dCtlPosition;
return noErr;
} else { return noErr; }
//FIXME: Should we fail if cmd isn't read or write?
}
OSErr RDiskAccRun(CntrlParamPtr p, DCtlPtr d, RDiskStorage_t *c) {
// Disable accRun
d->dCtlDelay = 0;
d->dCtlFlags &= ~dNeedTimeMask;
RDiskBreak();
// Set RAM disk buffer if our disk is writable and no RAM buffer set
if (!c->drvsts.writeProt && !c->ramdisk) {
if (*MMU32bit) { // If in 32-bit mode, (implies System 7)
// Allocate RAM disk buffer on system heap (System 7 can resize system heap)
c->ramdisk_alloc = NewPtrSys(RDiskSize);
if (c->ramdisk_alloc) { // If allocation successful,
// Set RAM disk buffer pointer
c->ramdisk = c->ramdisk_alloc;
}
} else { // Otherwise in 24-bit mode,
// Put buffer just beyond the 8 MB of RAM which is usable in 24-bit mode
c->ramdisk = (char*)(8 * 1024 * 1024);
//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
}
// Clear ramdisk_valid just in case, since ROM disk not yet copied to RAM disk
c->ramdisk_valid = 0;
}
if (!c->ramdisk) { // If RAM disk buffer couldn't be allocated,
// Mark write protected if we couldn't allocate RAM buffer?
c->drvsts.writeProt = -1;
} else if (c->ramdisk && !c->ramdisk_valid) { // Else if buffer exists but is not valid,
RDiskCopy_t copy24 = RDiskCopy24;
// Copy ROM disk to RAM disk buffer if not yet copied
if (*MMU32bit) { BlockMove(RDiskBuf, c->ramdisk, RDiskSize); }
else { copy24(RDiskBuf, c->ramdisk, RDiskSize); }
c->ramdisk_valid = 1;
}
return noErr; // Always return success
}
#pragma parameter __D0 RDiskControl(__A0, __A1)
OSErr RDiskControl(CntrlParamPtr p, DCtlPtr d) {
RDiskStorage_t *c;
// Fail if dCtlStorage null
if (!d->dCtlStorage) { return controlErr; }
// Dereference dCtlStorage to get pointer to our context
c = *(RDiskStorage_t**)d->dCtlStorage;
// Handle control request based on csCode
switch (p->csCode) {
case accRun:
if (!d->dCtlStorage) { return noErr; }
return RDiskAccRun(p, d, c);
default: return controlErr;
}
}
#pragma parameter __D0 RDiskStatus(__A0, __A1)
OSErr RDiskStatus(CntrlParamPtr p, DCtlPtr d) {
// Fail if dCtlStorage null
if (!d->dCtlStorage) { return statusErr; }
// Handle status request based on csCode
switch (p->csCode) {
case drvStsCode:
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;
if (c->ramdisk_alloc) { DisposePtr(c->ramdisk_alloc); }
HUnlock(d->dCtlStorage);
DisposeHandle(d->dCtlStorage);
d->dCtlStorage = NULL;
return noErr;
}