Another TRIM and kext question

Discussion in 'MacBook Pro' started by johnh57, Dec 15, 2014.

  1. johnh57 macrumors regular

    Joined:
    Jul 6, 2011
    Location:
    Montana
    #1
    Is there a way to know for sure if kext is disabled?

    I've run into a problem with cindori, where it is going through an endless cycle, enable trim - reboot to disable kext, enable trim - and it it says it needs to reboot to disable kext. The Cindori forums recommend to unisnstall and reinstall the trim software in this event. I hope this doesn't need to be done every time an apple update is issued and kext is enabled.
     
  2. Prodo123 macrumors 68020

    Prodo123

    Joined:
    Nov 18, 2010
    #2
    Enable TRIM, don't reboot, open Terminal and type "nvram boot-args=kext-dev-mode=1" then "sudo kextcache -system-prelinked-kernel" then reboot. Do not reset PRAM/NVRAM as it will erase this setting.

    If you cannot boot, hold down command-S for single user mode and type in the same command.

    This ensures TRIM Enabler's kext to load by first enabling unsigned kext loading and updating the known list of kexts in the boot cache.

    To find out exactly which kexts are loaded, the command kextstat will list all loaded kexts. Filter it with grep (kextstat | grep foo) for a cleaner output. This won't help you much, though, since TRIM Enabler does not install a new kext but rather modify preexisting ones instead.
     
  3. johnh57 thread starter macrumors regular

    Joined:
    Jul 6, 2011
    Location:
    Montana
    #3
    I thought the yosemite issue with trim on non-mac ssd's was that it would not allow a trim enabler to run unless kext was disabled - completely.
     
  4. Prodo123 macrumors 68020

    Prodo123

    Joined:
    Nov 18, 2010
    #4
    Apple's system kexts are signed such that the system knows they're valid. Sort of like how your immune system knows your body isn't a virus.

    TRIM Enabler adds certain IDs to force Apple's kexts to recognize 3rd party SSDs as their own. This however invalidates the signature permanently (the app makes a backup of the original with signature intact). As a result, the improper kext signature will make the system not load the storage driver which is not good.

    To fix this we turn off the signature checking entirely. Enabling kext-dev-mode does exactly that.
     
  5. johnh57, Dec 15, 2014
    Last edited: Dec 15, 2014

    johnh57 thread starter macrumors regular

    Joined:
    Jul 6, 2011
    Location:
    Montana
    #5
    What steps are necessary to update o/s and / or reset pram? As I understand the Cindori trim enabler, in order do any kind of o/s update, you have to shut down trim enabler, re-enable kext signing, and then perform the updates in order to avoid the grey screen of death.

    More Information - I have not yet tried the suggestion by Prodo123. It's on the list, but I don't understand exactly what that process will do so I'm a bit nervous about locking this thing up solid.

    I did run the machine a while, and then rebooted again.

    Currently I'm getting the message from Trim enabler that "the patch is not active, but Trim is enabled so I'm most likely running a mac ssd." I'm running a Samsung 840 evo. Checking system status for the SATA it is showing Trim Supported = yes.
     

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