MacOS – Kextual Healing: How to remove Kexts that appear on startup

kernel-extensionsmacosterminal

On my Mac I have a load of Kexts appearing that read like this (there are 14 or so):

The system extension "/System/Library/Extensions/BJUSBLoad.kext" was installed improperly and cannot be used…

Now they didn't start appearing after I consciously did anything, and I've read various threads about it elsewhere. I wonder if there is a programming solution here (using Terminal, perhaps) – something that will suppress the kexts? They mostly seem to relate to hp printer drivers, that sort of thing. Stuff I never use.

None of them seem to relate to things in my Login Items in System Preferences.

After discussing this on StackOverflow, I received some advice to run kextutil -n on them:

kextutil -n /System/Library/Extensions/BJUSBLoad.kext

So I did that, and got this:

/System/Library/Extensions/BJUSBLoad.kext – dependency 'com.apple.kernel.libkern' not found. Diagnostics for /System/Library/Extensions/BJUSBLoad.kext: Warnings: Personality CFBundleIdentifier differs from containing kext's (not necessarily a mistake, but rarely done): IJ170b…etc.

The message goes on, and ends like this:

Kext has no executable or compatible version, so it should not declare any OSBundleLibraries.
Code Signing Failure: not code signed

Any idea why or what I need to do?

Best Answer

See this Apple Support Communities thread - it addresses your exact problem (specifically, this response).

If you still have issues, prevent the kext from loading by using sudo + kextunload instead of kextutil. For example:

sudo kextunload /System/Library/Extensions/BJUSBLoad.kext

kextutil would be appropriate for debugging purposes (corrupted, missing dependencies, deprecated, etc) in the hopes of repairing it. kextunload is the tool you are looking for - see the man page for more info on it.

Related Solutions

MacOS – How to validate kexts signatures from the command line

Here's the script which will output not singed kexts inside this directory:

#!/bin/bash                                                                                                                                                                                                        

cd /System/Library/Extensions

find *.kext -prune -type d | while read d; do
    codesign -d "$d" 2>/dev/null
    rc=$?
    if [[ $rc != 0 ]] ; then
        echo "$d" is not signed.
    fi
done

MacOS – Kernel panic in old MacBook Pro after upgrading to El Capitan

I think I found your problem. It appears that you have one of the faulty Nvidia 9400m graphics cards in your computer. If you search on your model you will find lots of discussions (Apple Support, GoodBytes) about this system, and problems with the 9400m graphics card.

If you were running your system in “High Performance” graphics mode, then the system relied on the 9600m graphics card rather than the 9400m. So you would not have seen the dreaded flickering and green flash so many people reported on.

There is a fix, Apple released an EFI Firmware Update 2.8 for several systems including your MacBook in 2012.

But if you read through your kernel panic log you will see that you only have the 2.0 EFI Firmware in installed.

com.apple.driver.AppleEFINVRAM  2.0
com.apple.driver.AppleEFIRuntime    2.0

Hence the kernel panic you are seeing.

I would suggest that if you made a backup before you tried updating the system (you did make a backup right?) that you:

Boot your computer from your Snow Leopard pre-upgrade backup.
Go to  -> System Prefs -> Energy Saver and set your graphics card to High performance.
Try installing the EFI Firmware Update 2.8 from Snow Leopard.
NOTE: The installer will ONLY work from Mac OS X 10.5.8, 10.6.8 or 10.7.3. according to the Apple website.
Reboot to the internal drive, and the new El Capitan OS you already installed.

You might have to rerun the El Capitan installer again to get things working, but I have a feeling that you should be able to just boot up into El Capitan.

I hope this solves your problem.

ADDITION:
One additional workaround for this problem came to me from a friend.

You can try and disable (in Mavericks 10.9, Yosemite 10.10 and El Capitan 10.11) the Automatic Graphics Switching if you can boot into the the updated OS, and get to the System Prefs. This may disable the 9400m enough that you “might” not see the kernel panic again.

Best Answer

Related Solutions

MacOS – How to validate kexts signatures from the command line

MacOS – Kernel panic in old MacBook Pro after upgrading to El Capitan

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