A number of settings on a Mac are stored in Non-Volatile RAM, or NVRAM. NVRAM has a number of keys that contain values that define how the hardware is configured on a device that aren’t otherwise stored in the settings of an operating system. You can list all of the variables available using the -p option, as follows: nvram -p Variables in the available key pairs are managed using the nvram command as well. Each setting, which we’ll provide a list of below, can then be edited provided you have elevated privileges to do so, without any options defined. Most values are true and false and will need to be…
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Clear nvram In macOS Sierra
OS X has the ability to delete all of the firmware variables you’ve created. This can get helpful if you’ve got a bunch of things that you’ve done to a system and want to remove them all. If you run nvkram followed by a -p option you’ll see all of the configured firmware variables: nvram -p If you run it with a -d you’ll delete the given variables that you define (e.g. boot-args): nvram -d boot-args But, if you run the -c you’ll wipe them all: nvram -c
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Delete User Configurable nvram In Sierra (10.12)
A nifty little feature of nvram is the ability to delete all of the firmware variables you’ve created. This can get helpful if you’ve got a bunch of things that you’ve done to a system and want to remove them all. If you run nvkram followed by a -p option you’ll see all of the configured firmware variables: nvram -p If you run it with a -d you’ll delete the given variables that you define (e.g. boot-args): nvram -d boot-args But, if you run the -c you’ll wipe them all: nvram -c
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Delete User Configurable nvram In El Capitan
A nifty little feature of nvram is the ability to delete all of the firmware variables you’ve created. This can get helpful if you’ve got a bunch of things that you’ve done to a system and want to remove them all. If you run nvkram followed by a -p option you’ll see all of the configured firmware variables: nvram -p If you run it with a -d you’ll delete the given variables that you define (e.g. boot-args): nvram -d boot-args But, if you run the -c you’ll wipe them all: nvram -c
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Clear nvram
OS X has the ability to delete all of the firmware variables you’ve created. This can get helpful if you’ve got a bunch of things that you’ve done to a system and want to remove them all. If you run nvkram followed by a -p option you’ll see all of the configured firmware variables: nvram -p If you run it with a -d you’ll delete the given variables that you define (e.g. boot-args): nvram -d boot-args But, if you run the -c you’ll wipe them all: nvram -c
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Delete nvram
A nifty little new option that came in OS X 10.9 Mavericks and stays in Yosemite is the ability to delete all of the firmware variables you’ve created. This can get helpful if you’ve got a bunch of things that you’ve done to a system and want to remove them all. If you run nvkram followed by a -p option you’ll see all of the configured firmware variables: nvram -p If you run it with a -d you’ll delete the given variables that you define (e.g. boot-args): nvram -d boot-args But, if you run the -c you’ll wipe them all: nvram -c
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OS X 10.9 Mavericks Gives nvram A Delete All Option
A nifty little new option in OS X 10.9 Mavericks is the ability to delete all of the firmware variables you’ve created. This can get helpful if you’ve got a bunch of things that you’ve done to a system and want to remove them all. If you run nvkram followed by a -p option you’ll see all of the configured firmware variables: nvram -p If you run it with a -d you’ll delete the given variables that you define (e.g. boot-args): nvram -d boot-args But, if you run the -c you’ll wipe them all: nvram -c Enjoy!
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Those Pesky Firmware Passwords
The summer is upon us. Our users are watching videos like this one: While it’s actually way easier than what they show here, let’s look at stopping people from circumventing our admin goodness using the old school firmware password. Keep in mind, these passwords are somewhat easily reversible as they’re encrypted in a junior varsity way, so don’t use the same password that you use for anything else. To create our password in a script, we’re going to use EFIPW available http://code.google.com/p/efipw. Move the download to somewhere like /usr/local/bin folder. Then, to set the password to supah-secret: efipw_0.2b.py -p supah-secret -m command The client will now be in command mode,…
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Use ARD to Restart to NetBoot Server
It’s summer! And at many schools that means that the kids are gone and it’s time to start imaging again. And imaging means a lot of rebooting holding down the N key. But wait, you have ARD access into all those computers. And you have automated imaging tools. This means you can image the whole school from the comfort of your cabin out by the lake. Just use ARD and a little automation and you’ll be fishing in no time! If you haven’t used the bless command to restart a client to NetBoot server then you’re missing out. The bless command is used to set the boot drive that a…
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Mac OS X: Reset Open Firmware Password
To reset the open firmware password you can either reboot while resetting PRAM 3 or more times or just pull out the RAM, reboot and reseat it after the next restart. Have fun with that.