Please NOTE: Download and Install Firmware Uploader first.
After successful installation of Mac OS X 10.6.7 in my Toshiba M505-s4945 I was trying to compile AirPrime USB modem device driver that I modified earlier for Mac OS X 10.5.x installation. I could compile, install and load this driver successfully. But this would cause my built-in Toshiba mobile broadband device (Qualcomm Gobi) to hang. Since then, I was trying to find out any workaround and/or possible solution to this problem.
At first I tried to modify Info.plist of AppleUSBCDCACMData.kext to match my device and load. Though the device were matched and the KEXT were trying to start the USB device but it failed. Then I downloaded the source codes of AppleUSBCDC device driver dig more and was trying to figure out the problem.
Finally, I could come up with a patch where I just had to bypassed a snippet of code of AppleUSBCDCACMData driver. In that section of code the driver just checks or cross verifies the device Class, SubClass and Protocol.
1. Download the KEXT file from the following location if you are on Mac OS X 10.6.7.
2. Modify devide id (idProduct) in Info.plist of this KEXT. This id should match your modem device id that you see after uploading the firmware. My device id is 4878 (0x130e) after uploading the firmware. You can download the firmware up-loader that I have developed if you do not have it already.
3. Replace existing AppleUSBCDCACMData.kext in S/L/E/IOUSBFamily.kext/Contents/PlugIns/.
4. Repair permissions for AppleUSBCDCACMData.kext.
5. Restart (not mandatory I guess).