Kext-Dev-Mode=1

Discussion in 'Mac Pro' started by LightBulbFun, Oct 23, 2014.

  1. LightBulbFun macrumors 65816

    LightBulbFun

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    #1
    I was thinking about the fact that in Yosemite You have to use kext-dev-mode=1 to Load Unsigned kexts now every one rites it to pram and the issue that if the Pram gets cleared the system can fail to boot now I was thinking why cant u put kext-dev-mode=1 in the com.apple.boot.plist insted? reseting the pram wont reset that plist so it solves the issue that if pram is reset system failure could happen? I Put this in the mac pro forum as thats were the command is most used :cool::apple: So if some one could tell me if u can put it in the com.apple.boot.plist insted of pram thanks :)
     
  2. Skvo macrumors newbie

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    Jun 20, 2014
    #2
    Use in Terminal:

    sudo /usr/libexec/PlistBuddy -c "Set :'Kernel Flags' 'kext-dev-mode=1'" /Library/Preferences/SystemConfiguration/com.apple.Boot.plist
     
  3. matthewtoney macrumors regular

    matthewtoney

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    #3
    Yeah that puts it in there, but does this work as he posits?
     
  4. LightBulbFun thread starter macrumors 65816

    LightBulbFun

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    #4
    It works

    i can Confirm that it Dose work I Have an SSD in my MBP with the trim hack and I was able to use the methord above to add kext-dev-mode=1 to the com.apple.boot.plist and clear my PRAM and still boot up sucsefly with out eny hick ups and during verbouse booting i can see kext-dev-mode=1 listed in my boot args So this should solve the issue with kext signing and the risk of it being enabled when its disabled altho i am not sure if an OS update would reset the com.apple.boot.plist file?
     
  5. crjackson2134 macrumors 68030

    crjackson2134

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    #5
    That's a great catch, are there any known drawbacks? Does it affect boot times? Perhaps Cindori could use this information somehow to enhance TE. Perhaps including an option to set this mode with a slider or button.
     
  6. mikeboss, Nov 4, 2014
    Last edited: Nov 4, 2014

    mikeboss macrumors 65816

    mikeboss

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    #6
    YES!!! this totally works. and there aren't any drawbacks as far as I can tell. Cindori definitely needs to implement this option. I cleared nvram using the "nvram -c" command plus I used the option-command-p-r keys and Yosemite did still boot as if everything was normal. of course TRIM is still enabled :cool:
     
  7. crjackson2134, Nov 4, 2014
    Last edited: Nov 4, 2014

    crjackson2134 macrumors 68030

    crjackson2134

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    #7
    Awesome, going to set this on next session. :)

    UPDATE: So I just ran this command and reset the NVRAM through 4 cycles and all is well. Seems like this is a great fix.
     
  8. matthewtoney macrumors regular

    matthewtoney

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    #8
    Fantastic! This makes me feel much better about using Trim Enabler in Yosemite. To each their own opinion, but disabling the kext signing thing itself just doesn't bug me.
     
  9. mikeboss macrumors 65816

    mikeboss

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    #9
    hah! I don't know since when, but Trim Enabler already does modify the com.apple.Boot.plist and adds the "kext-dev-mode=1" line.
     
  10. crjackson2134 macrumors 68030

    crjackson2134

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    #10
    All this hullabaloo thinking we found something. Oh well, no harm.
     
  11. LightBulbFun thread starter macrumors 65816

    LightBulbFun

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    #11
    then tell me why befor I rote it to the plist when I Reset the PRAM the MacBook Pro failed to boot with the somthings broken prohibeted sign Yet when I did add it to the com.apple.boot.plist my self it worked no matter how meny times i cleared the PRAM boot with nvram -c and comand optoin P R?
     
  12. Gav Mack macrumors 68020

    Gav Mack

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    #12
    Can anyone with the Sintech card + Apple blade confirm that even though trim is enabled booting off the real thing after a pram reset with signing re-enabled with you still get the no entry sign on boot?
     
  13. mikeboss macrumors 65816

    mikeboss

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    #13
    as I wrote: I don't know since when Trim Enabler modifies com.apple.boot.plist. it sure didn't do this from the start. I tested it about an hour ago (on a fresh install of OS X Yosemite with a freshly downloaded version of TE) and I found the file modified after enabling TRIM. also the setting survived "nvram -c" and option-command-p-r.
     
  14. ibarnett macrumors regular

    ibarnett

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    #14
    Why would this happen?
    Did it happen to you?
    I installed mine yesterday (Sintech + Apple Blade) , displays as "Apple SSD" & trim is active through Yosemite automatically. I had previously uninstalled Trim Enabler.
    To be honest I don't want to try a pram reset to find out!
     
  15. Gav Mack macrumors 68020

    Gav Mack

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    #15
    No but my Sintech is ordered and I'm in hunting mode for the blade. I think my kexts may have to be done for the handoff card upgrade so I was curious as to whether it will stop the boot if the wifi/BT LE card was installed or is it only bootable devices on the OS X boot volume such as ahci, fw, usb etc which give you the no entry sign

    I presume the blade is rather good :D
     
  16. ibarnett macrumors regular

    ibarnett

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    #16
    It's just awesome!
    I really don't see anything being an issue booting after a reset.
    I have the bluetooth stuff as well from Macvidcards & had no issues prior to installing the Sintech & blade.
    Having spent all the time cloning etc I don't want to waste time with another install - so I will wait before another pram reset.
     
  17. Gav Mack macrumors 68020

    Gav Mack

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    #17
    :jealous: I need the 1tb part to replace my twin 840 Evo's and having played with the 1tb nMP and its disk performance in OS X and Windows and laughed at 'ludicrous speed' I am really going to enjoy that upgrade after!

    Suggests to me it's only boot devices that bring up the no entry and I'm very happy with that.
     
  18. VirtualRain macrumors 603

    VirtualRain

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    #18
    Indeed... Trim Enabler did modify my com.apple.boot.plist when I tried it earlier this evening, but the plist file doesn't look formatted properly (viewing it in TextEdit). Maybe it gets rid of a bunch of unnecessary stuff in the file while updating it or replaces it with a very sparse version. Not exactly best practice IMHO but it seems to work.
     
  19. mikeboss macrumors 65816

    mikeboss

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    #19
    I installed the 10.10.1 update and got the stop-sign again :mad: hm, will do more testing...
     
  20. VirtualRain macrumors 603

    VirtualRain

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    #20

    I updated to 10.10.1 before applying Trim Enabler. I hope every update doesn't break it. :(
     
  21. h9826790 macrumors G4

    h9826790

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    #21
    I did the update with TRIM enabled, no stop sign, but have to re-apply TRIM Enabler as expected.
     
  22. Cindori, Nov 6, 2014
    Last edited: Nov 6, 2014

    Cindori macrumors 68040

    Cindori

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    #22
    Hi all
    I am aware of this but it does not work 100%.
    I have had users contact me who have had the plist set with kext-dev-mode=1 but still receiving "invalid signature, omitting" and unable to boot. Also, I'm still not sure whether it can reset on OS updates.

    So since it does not seem to apply for all users, I am choosing to refer to the PRAM in my support article, since it seems to be the lower bound on expectation.

    Btw, Trim Enabler already uses both methods anyway (pram and plist) for maximum probability of success. You don't need to do these steps if you are using Trim Enabler.
     
  23. mikeboss macrumors 65816

    mikeboss

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    #23
    okay, I just tested this again. did a fresh install of Yosemite, installed Trim Enabler, zapped pram/cleared NVRAM. everything was working fine. I then installed the 10.10.1 update and the machine didn't boot anymore. exactly like cindori pointed out, this doesn't work 100% reliable. once more, I know why I got an Apple/SAMSUNG PCIe SSD for my main system...
     
  24. VirtualRain macrumors 603

    VirtualRain

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    #24
    So, when updating OS X Yosemite, is it best to turn Trim Enabler Off, Update, then Re-Enable Trim?
     
  25. Cindori macrumors 68040

    Cindori

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    #25
    Since Trim Enabler also sets the nvram, which is not reset on updates, there is a pretty low probability for any issues to occur (I would dare say near impossible). However, I still recommend it as a precaution.
     

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