After running v1.2 Thunderbolt Firmware update on an Apple MacBook Air 5,2 (Mid 2012) running Mac OS X 10.8.3 and Symantec Drive Encryption or PGP Whole Disk Encryption, the system is unable to boot. If you boot in verbose mode you will see an error on the screen (listed below).
Prohibitory sign in regular boot mode:
When booting into a more verbose boot you will see it stop at "still waiting for root device". The error keeps repeating:
Thunderbolt Firmware Update not working correctly with the Symantec Drive Encryption Driver (pgpwde.kext)
Symantec Corporation is committed to product quality and satisfied customers. This issue is currently being considered by Symantec Corporation to be addressed in a forthcoming version or Maintenance Pack of the product. Please be sure to refer back to this document periodically as any changes to the status of the issue will be reflected here.
The following is a known temporary workaround for the issue until the version/maintenance pack is released:
Scenario 1 The drive is encrypted and won't boot
Scenario 1 - Option A: Using the Recovery CD with an External USB drive
Note: To recover from this method you need access to a USB CD/DVD-ROM drive
Warning: Using the Recovery CD method can take several days to recover, depending on the size of the drive.
Download Symantec Drive Encryption Recovery Images found in this article
Boot the recovery CD.
To decrypt the drive, press "D" to begin the decryption.
Once you are decrypted, follow steps in Scenario 2.
Scenario 1 - Option B: Using Target Disk Mode via FireWire with a Thunderbolt to FireWire adapter
Note: Using this recovery method requires physical access to another Mac OS X system that you can use to control the affected MacBook Air which has a FireWire port and also access to a Thunderbolt to FireWire adapter.
Attach a Thunderbolt to FireWire adapter/cable to the Mac you are controlling the affected MacBook Air with.
Recover the system using Target Disk Mode. For this option please see this article on recovery via Target Disk Mode.
Once you are decrypted, follow the steps in Scenario 2.
Scenario 2 The drive is not encrypted and will not boot
Since the drive is not encrypted in this scenario, it is possible to boot into the recovery partition or use the Mac OS X installation disc and then open up a terminal utility and move the PGPwde.kext from /System/Library/Extensions to another location. You can then reboot the system. Symantec Drive Encryption (or PGP Whole Disk Encryption) is still installed at this point, but you will not be able to encrypt your disk.
Apple Mac OS X 10.8.3 with v1.2 Thunderbolt Firmware Update