Better checks for Mac images

src/QuirksCheck.cpp

@@ -1,7 +1,7 @@
 /**
  * This file is part of BlueSCSI
  *
- * Copyright (C) 2023 Eric Helgeson
+ * Copyright (C) 2023-2025 Eric Helgeson
  * Portions ZuluSCSI™ - Copyright (c) 2023-2025 Rabbit Hole Computing™
  * 
  * This file is licensed under the GPL version 3 or any later version. 
@@ -29,58 +29,56 @@
 #include "BlueSCSI_settings.h"
 #include "QuirksCheck.h"
 #include <assert.h>
-#include <stdint.h>
 
 
 static bool isValidMacintoshImage(image_config_t *img)
 {
-    bool result = true;
-    const char apple_magic[2] = {0x45, 0x52};
-    const char block_size[2]  = {0x02, 0x00};  // 512 BE == 2
-    const char lido_sig[4] = {'C', 'M', 'S', '_' };
-    uint8_t tmp[SD_SECTOR_SIZE];
-    // Check for Apple Magic
-    img->file.seek(0); 
-    img->file.read(tmp, SD_SECTOR_SIZE);
-    if (memcmp(apple_magic, tmp, 2) != 0)
-    {
-        dbgmsg("---- Apple magic not found.");
-        result = false;
+    // Mac block sizes should be the same size SD sector sizes for raw seeks, and reads to work
+    assert(MACINTOSH_BLOCK_SIZE == SD_SECTOR_SIZE);
+
+    constexpr char LIDO_SIGNATURE[] = {'C', 'M', 'S', '_' };
+    // Apple Volume Magic
+    // constexpr uint8_t APPLE_VOLUME_MAGIC[] {0x45, 0x52};
+    // 512 BE == 2
+    // constexpr uint8_t HFS_BLOCK_SIZE_HEX[] = {0x02, 0x00};
+    // HFS partitions start with BD at offset 1024.
+    constexpr uint8_t HFS_VOLUME_MAGIC[] {0x42, 0x44};
+
+    // Check for Raw HFS Volume start magic
+    if (2 * MACINTOSH_BLOCK_SIZE > img->file.size()) {
+        return false;
     }
-    // Check HFS Block size is 512
-    if (memcmp(block_size, &tmp[2], 2) != 0)
-    {
-        dbgmsg("---- Block size not 512", block_size);
-        result = false;
+    img->file.seek(2 * MACINTOSH_BLOCK_SIZE);
+    img->file.read(scsiDev.data, SD_SECTOR_SIZE);
+
+    if (memcmp(HFS_VOLUME_MAGIC, scsiDev.data, sizeof(HFS_VOLUME_MAGIC)) == 0) {
+        logmsg("---- ERROR: This is a bare HFS Volume. Use DiskJockey to convert it to a Device image.");
+        return false;
     }
-    uint8_t *mac_driver = &tmp[MACINTOSH_SCSI_DRIVER_OFFSET];
-    uint32_t driver_offset_blocks = mac_driver[0] << 24 | 
-                                    mac_driver[1] << 16 |
-                                    mac_driver[2] << 8  |  
-                                    mac_driver[3];
-    // Find size of SCSI Driver partition
-    uint8_t *mac_driver_size = &tmp[MACINTOSH_SCSI_DRIVER_SIZE_OFFSET];
-    uint32_t driver_size_blocks = mac_driver_size[0] << 8 | mac_driver_size[1];
+    const uint8_t *mac_driver = &scsiDev.data[MACINTOSH_SCSI_DRIVER_OFFSET];
+    const uint32_t driver_offset_blocks = mac_driver[0] << 24 |
+                                          mac_driver[1] << 16 |
+                                          mac_driver[2] << 8  |
+                                          mac_driver[3];
+    // Find the size of SCSI Driver partition
+    const uint8_t *mac_driver_size = &scsiDev.data[MACINTOSH_SCSI_DRIVER_SIZE_OFFSET];
+    const uint32_t driver_size_blocks = mac_driver_size[0] << 8 | mac_driver_size[1];
     // SCSI Driver sanity checks
-    if((driver_size_blocks * MACINTOSH_BLOCK_SIZE) > MACINTOSH_SCSI_DRIVER_MAX_SIZE ||
-        (driver_offset_blocks * MACINTOSH_BLOCK_SIZE) > img->file.size())
-    {
-        dbgmsg("---- Invalid Macintosh SCSI Driver partition detected.");
-        result = false;
-    }
-    // Contains Lido Driver - driver causes issues on a Mac Plus and is generally slower than the Apple 4.3 or FWB.
-    // Also causes compatibility issues with other drivers.   
-    // Mac block sizes should be the same size SD sector sizes for raw seeks, and reads to work 
-    assert(MACINTOSH_BLOCK_SIZE == SD_SECTOR_SIZE);
-    img->file.seek(driver_offset_blocks * MACINTOSH_BLOCK_SIZE); 
-    img->file.read(tmp, SD_SECTOR_SIZE);
-    uint8_t* lido_driver = &tmp[LIDO_SIG_OFFSET];
-    if(memcmp(lido_sig, lido_driver, 4) == 0)
+    if(!((driver_size_blocks * MACINTOSH_BLOCK_SIZE) > MACINTOSH_SCSI_DRIVER_MAX_SIZE ||
+        (driver_offset_blocks * MACINTOSH_BLOCK_SIZE) > img->file.size()))
     {
-        logmsg("---- WARNING: This drive contains the LIDO driver and may cause issues.");
+        // Check if Lido Driver - driver causes issues on a Mac Plus and is generally slower than the Apple 4.3 or FWB.
+        // Also causes compatibility issues with other drivers.
+        img->file.seek(driver_offset_blocks * MACINTOSH_BLOCK_SIZE);
+        img->file.read(scsiDev.data, SD_SECTOR_SIZE);
+        uint8_t* lido_driver = &scsiDev.data[LIDO_SIG_OFFSET];
+        if(memcmp(LIDO_SIGNATURE, lido_driver, sizeof(LIDO_SIGNATURE)) == 0)
+        {
+            logmsg("---- WARNING: This drive contains the LIDO driver and may cause issues. Use DiskJockey to replace it.");
+            return false;
+        }
     }
-
-    return result;
+    return true;
 }
 
 // Called from BlueSCSI_disk after image is initalized.
@@ -95,18 +93,11 @@ static void macQuirksSanityCheck(image_config_t *img)
 
     if(img->deviceType == S2S_CFG_FIXED)
     {
-        if(!isValidMacintoshImage(img))
-        {
-            logmsg("---- WARNING: This image does not appear to be a valid Macintosh disk image.");
-        }
-        else
-        {
-            dbgmsg("---- Valid Macintosh disk image detected.");
-        }
+        isValidMacintoshImage(img);
     }
     
-    // Macintosh hosts reserve ID 7, so warn the user this configuration wont work
-    if((img->scsiId & S2S_CFG_TARGET_ID_BITS) == 7)
+    // Macintosh hosts reserve ID 7, so warn the user this configuration won't work
+    if((img->scsiId & S2S_CFG_TARGET_ID_BITS) == S2S_CFG_TARGET_ID_BITS)
     {
         logmsg("---- WARNING: Quirks set to Apple so can not use SCSI ID 7!");
     }