IOPCIDevice not linked when loading kext - iokit

Question

I am trying to write a driver for a PCI composite video capture card for OSX.
The kext builds just fine, but when I try to load it, I get this:
Diagnostics for /System/Library/Extensions/Conexant878.kext:
Code Signing Failure: code signature is invalid
WARNING - Invalid signature -67030 0xFFFFFFFFFFFEFA2A for kext "/System/Library/Extensions/Conexant878.kext"
(kernel) kxld[com.akasaka.Conexant878]: The following symbols are unresolved for this kext:
(kernel) kxld[com.akasaka.Conexant878]: __ZN11IOPCIDevice22_RESERVEDIOPCIDevice16Ev
(kernel) kxld[com.akasaka.Conexant878]: __ZN11IOPCIDevice22_RESERVEDIOPCIDevice17Ev
(kernel) kxld[com.akasaka.Conexant878]: __ZN11IOPCIDevice22_RESERVEDIOPCIDevice18Ev
(kernel) kxld[com.akasaka.Conexant878]: __ZN11IOPCIDevice22_RESERVEDIOPCIDevice19Ev
(kernel) kxld[com.akasaka.Conexant878]: __ZN11IOPCIDevice22_RESERVEDIOPCIDevice20Ev
(kernel) kxld[com.akasaka.Conexant878]: __ZN11IOPCIDevice22_RESERVEDIOPCIDevice21Ev
(kernel) kxld[com.akasaka.Conexant878]: __ZN11IOPCIDevice24getDeviceMemoryWithIndexEj
(kernel) Can't load kext com.akasaka.Conexant878 - link failed.
(kernel) Failed to load executable for kext com.akasaka.Conexant878.
(kernel) Kext com.akasaka.Conexant878 failed to load (0xdc008016).
(kernel) Failed to load kext com.akasaka.Conexant878 (error 0xdc008016).
Failed to load /System/Library/Extensions/Conexant878.kext - (libkern/kext) link error.
Check library declarations for your kext with kextlibs(8).
The kextlibs output is as follows:
For all architectures:
com.apple.iokit.IOPCIFamily = 2.9
com.apple.kpi.iokit = 13.4
com.apple.kpi.libkern = 13.4
For x86_64:
7 symbols not found in any library kext:
__ZN11IOPCIDevice24getDeviceMemoryWithIndexEj
__ZN11IOPCIDevice22_RESERVEDIOPCIDevice16Ev
__ZN11IOPCIDevice22_RESERVEDIOPCIDevice18Ev
__ZN11IOPCIDevice22_RESERVEDIOPCIDevice20Ev
__ZN11IOPCIDevice22_RESERVEDIOPCIDevice17Ev
__ZN11IOPCIDevice22_RESERVEDIOPCIDevice19Ev
__ZN11IOPCIDevice22_RESERVEDIOPCIDevice21Ev
My Info.plist contains all of the OSBundleLibraries I could think of being necessary in this context, but that is still a no-go:
...
<key>IOClass</key>
<string>ConexantTuner</string>
<key>OSBundleRequired</key>
<string>Local-Root</string>
<key>IOPCIMatch</key>
<string>0x036e109e</string>
<key>IOProviderClass</key>
<string>IOPCIDevice</string>
<key>IOKitPersonalities</key>
<dict/>
<key>OSBundleLibraries</key>
<dict>
<key>com.apple.iokit.IOPCIFamily</key>
<string>1.0.0b1</string>
<key>com.apple.kpi.mach</key>
<string>8.0</string>
<key>com.apple.kpi.unsupported</key>
<string>8.0</string>
<key>com.apple.kpi.iokit</key>
<string>8.0</string>
<key>com.apple.kpi.libkern</key>
<string>8.0</string>
<key>com.apple.kpi.bsd</key>
<string>8.0</string>
</dict>
</dict>
</plist>
What else can I attempt to determine what else I need to depend upon in order to get this to work?
Thanks in advance.
C++Filt output of the unresolved symbols:
IOPCIDevice::getDeviceMemoryWithIndex(unsigned int)
IOPCIDevice::_RESERVEDIOPCIDevice16()
IOPCIDevice::_RESERVEDIOPCIDevice18()
IOPCIDevice::_RESERVEDIOPCIDevice20()
IOPCIDevice::_RESERVEDIOPCIDevice17()
IOPCIDevice::_RESERVEDIOPCIDevice19()
IOPCIDevice::_RESERVEDIOPCIDevice21()

Answer 1

Sounds like a mismatch between the SDK version you are building against and the OS X version you are trying to load your kext on. Unlike OS X userspace, setting the "Deployment Target" to the minimum OS X version supported by your driver is not sufficient. You must also use the OS X SDK version matching the oldest supported OS X version for this very reason of reserved virtual functions.
So e.g. maybe you're building with the 10.10 or 10.11 SDK, but are trying to load the kext on 10.9. That won't work. Use Xcode 6.3.2 (the newest version that ships with the 10.9 SDK), select the 10.9 SDK, and build with that.