For NewWorld ROM, implement the bootdriver setting by reordering the drive queue once CD-ROM drives are added

BasiliskII/src/cdrom.cpp

@@ -448,6 +448,9 @@ int16 CDROMOpen(uint32 pb, uint32 dce)
 			Execute68kTrap(0xa04e, &r);		// AddDrive()
 		}
 	}
+
+	CDROMOpenDone();
+
 	return noErr;
 }
 

BasiliskII/src/include/cdrom.h

@@ -40,4 +40,6 @@ extern int16 CDROMPrime(uint32 pb, uint32 dce);
 extern int16 CDROMControl(uint32 pb, uint32 dce);
 extern int16 CDROMStatus(uint32 pb, uint32 dce);
 
+extern void CDROMOpenDone(void); // Called by CDROMOpen() once drives have been to the drive queue
+
 #endif

BasiliskII/src/main.cpp

@@ -202,6 +202,8 @@ bool InitAll(const char *vmdir)
 	return true;
 }
 
+void CDROMOpenDone() {
+}
 
 /*
  *  Deinitialize everything

SheepShaver/src/include/macos_util.h

@@ -353,6 +353,7 @@ extern void Enqueue(uint32 elem, uint32 list);			// Enqueue QElem to list
 extern int FindFreeDriveNumber(int num);				// Find first free drive number, starting at "num"
 extern void MountVolume(void *fh);						// Mount volume with given file handle (see sys.h)
 extern void FileDiskLayout(loff_t size, uint8 *data, loff_t &start_byte, loff_t &real_size);	// Calculate disk image file layout given file size and first 256 data bytes
+extern void MoveDrivesFromDriverToFront(uint32 driverRefNum); // Move drives from the given driver to the head of the drive queue
 extern uint32 FindLibSymbol(const char *lib, const char *sym);	// Find symbol in shared library
 extern void InitCallUniversalProc(void);				// Init CallUniversalProc()
 extern long CallUniversalProc(void *upp, uint32 info);	// CallUniversalProc()

SheepShaver/src/macos_util.cpp

@@ -103,6 +103,32 @@ void Enqueue(uint32 elem, uint32 list)
 	}
 }
 
+static void InsertQueueEntry(uint32 elem, uint32 at, uint32 list) {
+    uint32 next = ReadMacInt32(at);
+    WriteMacInt32(at, elem);
+    WriteMacInt32(elem + qLink, next);
+    if (next == 0) {
+        // inserted at end
+        WriteMacInt32(list + qTail, elem);
+    }
+}
+
+static void RemoveQueueEntry(uint32 at, uint32 list) {
+    uint32 e = ReadMacInt32(at);
+    uint32 next = ReadMacInt32(e + qLink);
+
+    if (next == 0) {
+        // removing from end
+        if (at == list + qHead) {
+            WriteMacInt32(list + qTail, 0);
+        } else {
+            WriteMacInt32(list + qTail, at - qLink);
+        }
+    }
+
+    WriteMacInt32(at, next);
+    WriteMacInt32(e + qLink, 0);
+}
 
 /*
  *  Find first free drive number, starting at num
@@ -127,6 +153,37 @@ int FindFreeDriveNumber(int num)
 	return num;
 }
 
+/*
+ *  Move drives of the given driver to the front of the drive queue
+ */
+void MoveDrivesFromDriverToFront(uint32 driverRefNum) {
+
+    const uint32 DrvQHdr = 0x308; // drive queue address
+
+    uint32 nextInsertPos = DrvQHdr + qHead;
+
+    uint32 ptrToElem = DrvQHdr + qHead;
+    uint32 e = ReadMacInt32(ptrToElem);
+    while (e) {
+        uint32 next = ReadMacInt32(e + qLink);
+
+        uint32 d = e - dsQLink;
+		uint32 curRefNum = ReadMacInt16(d + dsQRefNum);
+
+        if ((curRefNum & 0xffff) == (driverRefNum & 0xffff)) {
+            RemoveQueueEntry(ptrToElem, DrvQHdr);
+            InsertQueueEntry(e, nextInsertPos, DrvQHdr);
+
+            nextInsertPos = e + qLink;
+
+			// after the removal, ptrToElem already points to next
+        } else {
+			ptrToElem = e + qLink;
+		}
+
+        e = next;
+    }
+}
 
 /*
  *  Mount volume with given file handle (call this function when you are unable to

SheepShaver/src/main.cpp

@@ -264,6 +264,17 @@ bool InitAll(const char *vmdir)
 	return true;
 }
 
+void CDROMOpenDone() {
+	// At this point, any initial CD-ROM drives have been added to the drive queue.
+	if (ROMType == ROMTYPE_NEWWORLD) {
+		// The PRAM boot device setting has no apparent effect,
+		// but we can achieve a boot with the specified device by reordering the drive queue ourselves.
+		int bootdriver = PrefsFindInt32("bootdriver");
+		if (bootdriver) {
+			MoveDrivesFromDriverToFront(bootdriver);
+		}
+	}
+}
 
 /*
  *  Deinitialize everything