Hi guys, I'm sorry for a rather long post. I need to develop an IOMedia driver which has its own bdevsw table, something similar to IOMediaBSDClient. If it works properly, this driver should sit above all IOMedia devices that have a specific signature in their superblock label. That way the driver would replace IOMediaBSDClient for these devices. I have approached this problem from 3 angles, but none of them gave me any success: 1. I copied IOMediaBSDClient, IOMedia and IOBlockStorageDriver code and renamed it to IOMediaBSDClientTest, IOMediaTest and IOBlockStorageDriverTest, respectively. IOMediaBSDClientTest is a subclass of IOMediaBSDClient and its getProvider() method returns IOMediaTest. IOMediaTest is a subclass of IOMedia and its getProvider() method returns IOStorage. IOBlockStorageDriverTest is a subclass of IOBlockStorageDriver and its getProvider() method returns IOBlockStorageDevice. This is the plist for it: <dict> ... <key>IOKitPersonalities</key> <dict> <key>IOBlockStorageDriverTest</key> <dict> <key>CFBundleIdentifier</key> <string>com.test.iokit.IOMediaBSDClientTest</string> <key>IOClass</key> <string>IOBlockStorageDriverTest</string> <key>IOPropertyMatch</key> <dict> <key>device-type</key> <string>Generic</string> </dict> <key>IOProviderClass</key> <string>IOBlockStorageDevice</string> </dict> <key>IOMediaBSDClientTest</key> <dict> <key>CFBundleIdentifier</key> <string>com.test.iokit.IOMediaBSDClientTest</string> <key>IOClass</key> <string>IOMediaBSDClientTest</string> <key>IOMatchCategory</key> <string>IOMediaBSDClient</string> <key>IOProbeScore</key> <integer>60001</integer> <key>IOProviderClass</key> <string>IOMediaTest</string> <key>IOResourceMatch</key> <string>IOBSD</string> </dict> </dict> ... <key>OSBundleLibraries</key> <dict> <key>com.apple.iokit.IOStorageFamily</key> <string>1.2.3</string> <key>com.apple.kernel.bsd</key> <string>1.1</string> <key>com.apple.kernel.iokit</key> <string>1.1</string> <key>com.apple.kernel.libkern</key> <string>1.1</string> </dict> <key>OSBundleRequired</key> <string>Local-Root</string> </dict> After I put this kext in /System/Library/Extensions, and rebooted with boot-args="-v", I got a panic almost immediately in my IOKit kext. This indicates to me that my kext gets loaded and matched and actually gets used but something is seriously wrong, although I haven't changed anything from the original code except for the names. Anyway, I can't debug it because it is too early in the startup sequence. 2. I copied the IOMediaBSDClient class only and renamed it to IOMediaBSDClientTest. I also made this kext depend on IOStorageFamily kext, so it doesn't have undefined symbols. IOMediaBSDClientTest is a subclass of IOMediaBSDClient and its getProvider() method returns IOMedia. This is the plist for it: <dict> ... <key>IOKitPersonalities</key> <dict> <key>IOMediaBSDClientTest</key> <dict> <key>CFBundleIdentifier</key> <string>com.test.iokit.IOMediaBSDClientTest</string> <key>IOClass</key> <string>IOMediaBSDClientTest</string> <key>IOMatchCategory</key> <string>IOMediaBSDClient</string> <key>IOProbeScore</key> <integer>65536</integer> <key>IOProviderClass</key> <string>IOMedia</string> <key>IOResourceMatch</key> <string>IOBSD</string> <key>Leaf</key> <true/> </dict> </dict> ... <key>OSBundleLibraries</key> <dict> <key>com.apple.iokit.IOStorageFamily</key> <string>1.2.3</string> <key>com.apple.kernel.bsd</key> <string>1.1</string> <key>com.apple.kernel.iokit</key> <string>1.1</string> <key>com.apple.kernel.libkern</key> <string>1.1</string> </dict> <key>OSBundleRequired</key> <string>Local-Root</string> </dict> This kext loaded with no problems but it never got used. kextstat shows the kext has already been loaded. I suspect it is because the IOStorageFamily kext has loaded first and thus IOMediaBSDClient has a higher probability of getting used, even though I have given this kext a much higher IOProbeScore. 3. I copied IOCDStorageFamily project and renamed all occurences of IOCD to IOTest. This kext loaded with no problems when done manually, but if you reboot the box, the box won't even be able to boot. It gives me the apple logo with a black box on top of it. This is the plist for it: <dict> ... <key>IOKitPersonalities</key> <dict> <key>IOTestPartitionScheme</key> <dict> <key>CFBundleIdentifier</key> <string>com.test.iokit.IOTestStorageFamily</string> <key>Content Mask</key> <string>CD_partition_scheme</string> <key>Content Table</key> <dict> ... </dict> <key>IOClass</key> <string>IOTestPartitionScheme</string> <key>IOMatchCategory</key> <string>IOStorage</string> <key>IOProviderClass</key> <string>IOTestMedia</string> </dict> <key>IOTestBlockStorageDriver</key> <dict> <key>CFBundleIdentifier</key> <string>com.test.iokit.IOTestStorageFamily</string> <key>IOClass</key> <string>IOTestBlockStorageDriver</string> <key>IOPropertyMatch</key> <dict> ... </dict> <key>IOProviderClass</key> <string>IOTestBlockStorageDevice</string> </dict> <key>IOTestMediaBSDClient</key> <dict> <key>CFBundleIdentifier</key> <string>com.test.iokit.IOTestStorageFamily</string> <key>IOClass</key> <string>IOTestMediaBSDClient</string> <key>IOMatchCategory</key> <string>IOMediaBSDClient</string> <key>IOProbeScore</key> <integer>61000</integer> <key>IOProviderClass</key> <string>IOTestMedia</string> </dict> </dict> <key>OSBundleLibraries</key> <dict> <key>com.apple.iokit.IOStorageFamily</key> <string>1.2.3</string> <key>com.apple.kernel.bsd</key> <string>1.1</string> <key>com.apple.kernel.libkern</key> <string>1.1</string> <key>com.apple.kernel.mach</key> <string>1.1</string> </dict> <key>OSBundleRequired</key> <string>Local-Root</string> </dict> If everything goes according to plan, this driver should sit above all CD media, replacing IOCDMediaBSDClient, correct? Has someone done this before? or maybe can help me with this? Thanks, Herry Wiputra _______________________________________________ darwin-kernel mailing list | darwin-kernel@lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored.