I've had a Macbook Pro for a year or so now and have experimented with quite a few Linux distributions which have added and changed things in the EFI Boot Order. I am looking to clean things up. The tool efibootmgr for Linux does let me make changes and cleanup as necessary. However will resetting NVRAM reset the EFI Boot Order for me?

I'm developing a macOS tool (in C#) to read or modify NVRAM variables, specifically boot-args. My code runs perfectly on Apple Silicon M2 Macs with macOS Ventura, but consistently fails on M4 chips running macOS Sequoia. In C#, I execute: Executer.execute("nvram", "boot-args", null, true, false, true, true, out stdout, out stderr, out exitCode, out killed, 60); On Sequoia, exitCode is always non-zero, and the command can’t read or write NVRAM. Has anyone faced this issue on newer macOS/M4 hardware? Are there changes in Sequoia or restrictions I should be aware of? Any workarounds or solutions? Thanks!

There have been answers that describe how this can be prevented for Intel Macs using an NVRAM setting, but this AutoBoot setting has no effect on an M1 Mac. There is a similar auto-boot setting in the M1 Mac NVRAM list, which is set to true by default, but setting it to false or %00 will cause the Mac to be unbootable. I have not found a way to prevent boot when the lid is open on an M1 Mac.

I have a problem with my iMac restarting when it should be shutting down. This doesn't happen all the time but appears to happen more frequently when I've had the computer on for a few hours. **What happens** 1. I shut the computer down via Apple Menu > Shut Down 2. The shut down cycle completes 3. The computer immediately reboots It doesn't behave like this https://apple.stackexchange.com/questions/102486/mac-os-x-never-shuts-down . The Mac responds to being shut down immediately. **Fixes I've tried** First I should state I've pulled out all USBs etc. The only wire in is the power cable. *Disk Utility* I've been in touch with Apple Support about this issue, and the only advice they could give was to run First Aid in the Disk Utility. Sometimes this allows me to shut down. Other times not. *Resetting the SMC* I've reset the SMC which doesn't help. This often leads to another issue which is freezing on reboot (Apple logo and progress bar that doesn't move). To fix this I reset the PRAM/VRAM *Reset the PRAM/VRAM* Resetting the PRAM allows me to shut down most of the time. Even then I have to do it 2 or 3 times before it works. *Complete reinstall/upgrade* I've also reinstalled the system twice, one time upgrading from El Capitan to Sierra. This has temporarily fixed the issue, but it soon comes back after a week or so. **Setup** iMac (27-inch, Late 2013) 3.4 GHz Intel Core i5 6 GB 1600 MHz DDR3 NVIDIA GeForce GTX 775M 2048 MB macOS Sierra 10.12.5 **EDIT:** Current Energy Saver Settings I'd really appreciate your help here guys, this has been going on a while and it's becoming a bit of a nuisance. **EDIT:** This question appears to highlight a pretty common occurrence. I'm happy to invest more into the bounty to get an answer that resolves or at least identifies the problem causing it to happen. **UPDATE:** After going through the steps in the answer provided by @monomeeth, Apple Diagnostics uncovered an error NDT001: There may be an issue with the Thunderbolt hardware. I've run Diagnostics before, but this time I ran it straight after the Mac restarted from a failed shut down. I'll be taking it into Apple for repair, so I'll keep this answer up to date with the outcome.

I cannot reset my NVRAM at startup (holding down ⌘ Command⌥ OptionPR does nothing), but I want to reset the NVRAM so I am trying to reset it with Terminal. $ sudo nvram -c nvram: Error clearing firmware variables: (iokit/common) not permitted How do I reset the NVRAM?

I had an issue with RAM on my old logic board of a 2011 MacBook Air. I decided to replace the old logic board with a more recent i7 2017 logic board. I got to get all running but the keyboard and the trackpad. Unfortunately with no keyboard I can’t power up the laptop, but that’s not the biggest issue as far I keep it always on. I tried to reset nvram through terminal but no way, I get error clearing firmware variables (iokit/common) not permitted. Does anybody have any clue why keyboard is not responding at all? Any suggestions on how to fix it? I am currently using a Bluetooth keyboard and a usb mouse but it’s not the same as being able to use the built-in ones. Together with the the logic board I replaced the I/O, hard drive, airport but all the rest fitted perfectly. And yes, I did connect the keyboard and the trackpad with the logic board. Thank you in advance for any help. It will be very much appreciated. I’m kind of stuck here.

When I run nvram -x HW_BOOT_DATA the output in the data field appears to be a base64 encoded binary string. The length remains constant but some of the bits change between runs. How do I interpret this field? What do the different bits mean? I have a 2018 Mac Mini running macOS Monterey 12.6.

I have a 2018 Mac Mini running macOS Monterey 12.6. The Mac is connected to a single external monitor using HDMI. Whenever the Mac wakes from sleep or is restarted normally, the monitor has no signal. I am still able to ssh into the machine when this happens, but there are no displays listed. Using a different external monitor from a different brand, using a different HDMI cable, or switching to a USB-C connection does not fix the problem. The only thing that consistently fixes the problem is restarting the computer and holding down the keys Cmd+Opt+P+R to reset NVRAM. However, this only works for one restart, and the monitor will say no signal again the next sleep/restart. I look at the NVRAM variables after the reset and the only variable that seems potentially relevant is HW_BOOT_DATA but it is not clear to me how to interpret that data. I would like to find a solution to this problem that does not involve resetting NVRAM and restarting.

I've installed DosDude's patches to get Catalina running on my Mac Pro 4,1. However, I'm a Dvorak typist, and now I find I'm booting Catalina in "Canadian English" layout instead of Dvorak. So I have to struggle to type in my password! After I log in, I do have the Dvorak layout. I thought this was in NVRAM, but the only interesting output from "nvram -p" is "prev-lang:kbd" which is set to "en:16300", which is exactly what you'd want for Dvorak . So, how can I boot Catalina and have it come up in Dvorak layout?

On boot, when I press **Shift+Option+Command+r**, a globe appears with a dropdown box to choose my ssid and password. After some time the **Sierra** Utilities starts and my wi-fi connection is enabled. This is not happening when I press **Option+Command+r** on Boot to get to the **Monterey** utilities. I get the same Globe with the dropdown box, but after the Utilities screen starts, my wi-fi is not connected, so it doesn't seems to be saved. I never inserted my wi-fi credentials on a final installation, only on the globe screen and on the Monterey utilities when I attempted an Online Recovery that I canceled. After that, I made a nvram/smc reset and formatted the disk again (disk utility > show all devices > choose the ssd disk > erase). How is this happening? Is it possible that Sierra, unlike Monterey, can get the wi-fi information from the globe part? Thanks.

My mid-2009 13" unibody MacBook Pro died years ago. It's probably not worth fixing. I'm just curious if a dead CMOS/PRAM battery could have caused its demise? *iFixIt* doesn't list any non-primary batteries in its online store or replacement guides for any unibody Macbook Pros. Did these models lack one altogether or was it just soldered to the logic board (In which case it'd be kind of like [planned obsolescence](https://en.wikipedia.org/wiki/Planned_obsolescence)) ?

Tonight my 2019 MacBook Pro mysteriously stopped working correctly with my external (USB3) DVD drive. However, I know the drive is fine because my Windows machine and my old 2016 MacBook Pro can use it without issue. Not sure what happened, but after spinning up the disc, my Mac OS didn't have the disc mounted. This time I had the drive plugged into a USB 2.0 hub (which I don't normally use), so I pulled it out of that and moved it to the USB-c port and tried again. This time it didn't spin at all and instead made a steady soft "click... click... click" sound. And now that's all it will do on this Mac, no matter which port or USB3-to-c adapter I try. I hypothesize that my MacBook's driver for this DVD drive is now in some kind of faulty state (maybe due to the USB 2 hub or the act of hot-unplugging it from that), but I cannot figure out how to make the OS "forget" this drive and try it fresh. **I *have* reset the NVRAM**, and it didn't do anything. When I look at the USB section of System Information, I see like 100 instances of my DVD drive, and every time I refresh it, there's more. So Mac OS is clearly doing something wrong. Seems like it keeps trying to init the drive, fails, and then tries again without clearing the previous attempt: Anyone know what I can try now? **Answers to questions:** **1. Have you tried using all of the different USB ports available on the Mac** Yes. **2. Can you open terminal.app, run the following command, and attach the output to this question: diskutil list** Here you go:

1168 ~$ diskutil list
/dev/disk0 (internal, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *1.0 TB     disk0
   1:                        EFI ⁨EFI⁩                     314.6 MB   disk0s1
   2:                 Apple_APFS ⁨Container disk1⁩         1.0 TB     disk0s2

/dev/disk1 (synthesized):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      APFS Container Scheme -                      +1.0 TB     disk1
                                 Physical Store disk0s2
   1:                APFS Volume ⁨Macintosh HD⁩            15.3 GB    disk1s1
   2:              APFS Snapshot ⁨com.apple.os.update-...⁩ 15.3 GB    disk1s1s1
   3:                APFS Volume ⁨Macintosh HD - Data⁩     202.7 GB   disk1s2
   4:                APFS Volume ⁨Preboot⁩                 474.6 MB   disk1s3
   5:                APFS Volume ⁨Recovery⁩                622.9 MB   disk1s4
   6:                APFS Volume ⁨VM⁩                      2.1 GB     disk1s5

I have a Mac mini 2020 (with the Apple Silicon M1 chip). I want it to boot up in verbose mode, i.e. the details of the boot process should be logged as text on the screen during bootup. The following command is recommended by several articles :

sudo nvram boot-args="-v"

And this does indeed work fine on my Macbook Pro 2018 and Mac mini 2018, however, it seems to do nothing on my Mac mini 2020. I have confirmed using nvram -p (and System Information) that the boot-args property is indeed set to -v, but it has no effect. Is there some way to get this to work?

Is it possible to enable serverperfmode on an Apple Silicon Mac? I am using an M1 Mac Mini on macOS 11.2, and following Apple's instructions . I enabled serverperfmode=1 in the NVRAM boot-args, and restarted the machine. However, I'm not seeing any of the values in sysctl -a, ulimit -u, or ulimit -n change. I have successfully done this on Intel-based Mac Minis in the past. Is it possible that serverperfmode is simply not supported on Apple Silicon Macs? Here are some of the values I'm seeing on this machine, which seem unchanged from before enabling serverperfmode.

% nvram boot-args                   
boot-args	serverperfmode=1
% ulimit -n                           
256
% ulimit -u                              
2666

Command+Option+P+R does nothing, and executing

-xp

and

-c

returns the same

is not supported on this system

This is on a clean install of Yosemite (installation of El Cap and above fails every time), on a SATA internal SSD. Edit: The underlying issue I'm trying to fix is slow boot times. Yosemite is installed on an SSD, yet it still takes about 2 minutes and 20 seconds to boot up. I've recorded a video of it booting up in verbose mode, but I've yet to decide whether to upload that or try to get a text dump of the console. Edit 2: Watch the iMac boot in real-time, with verbose output: https://streamable.com/9fa6h6 Edit 3: Output of

-p IODeviceTree

https://pastebin.com/BGJvkYea Edit 4: Boot ROM is

.00CC.B00

and SMC version (system) is

.53f13

. There is nothing in

/System/Library/CoreServices/Firmware Updates/

. Any chance that something like this (https://www.reddit.com/r/hackintosh/comments/adxdb0/the_bodgers_guide_to_getting_nvram_working/) can fix it, partially or otherwise?

I bought a used Mac Mini (2018) from a (used Mac reseller), and today I've noticed that the previous owner is still signed in to Find My Mac (but it is me who is signed in to this Mac's iCloud). Looking at: Preferences -> Internet Accounts -> iCloud -> Find my Mac I see: Find my Mac already in use (as on the attached screenshot). When I click on that option it displays the previous owner appleid email and asks me for his password (which obviously I don't and I won't have). While doing the clean reinstall I went through the NVRAM clear procedure, so I assume it was cleared then, or this is a variables that cannot be cleared this way. I found this article, although it is old, describing how to reset the appropriate NVRAM variables: https://tidbits.com/2016/07/22/disable-find-my-mac-by-resetting-nvram/ The solution from the article is to do: nvram -d fmm-computer-name nvram -d fmm-mobileme-token-FMM I didn't do that yet, because: 1 - it should've been cleared already so it probably got recreated based on my Mac's serial, 2 - I read in some places that this doesn't work anymore, 3 - I'm not sure if that won't block or break current configuration of my Mac. When I do: nvram -p | grep fmm it returns 3 vars:

fmm-mobileme-token-FMM
fmm-mobileme-token-FMM-BridgeHasAccount
fmm-computer-name

The first one contains the email and some data of the previous owner like name and email plus some encoded data. My questions: 1. If I want to regain access to Find my Mac then the only option in that case is to try to contact the previous owner and ask him to remove this device from his iCloud? 2. Can this user still block / erase remotely my Mac as long as it is present at his iCloud? Does it change anything that I'm successfully logged in to iCloud on this Mac?

My MacBook Pro is 16 inch bought from 2019 and the macOS version is Big Sur. Last week, **I reset the nvram** then I found I have to choose language option every time I go into recover mode (by using Command + R after boot). Before that, I don't need to choose any language option when I go into the recover mode. That's so weird because I don't think I'm suppose to choose language every time. What I tried: Go to recover mode again, choose the language, and enter the password of User account. Then reboot machine, go to the recover mode, still found I need to choose the language. Is there any idea that can solve this issue?

I have installed macOS Big Sur as a guest system in Parallels Desktop 16. I disabled SIP. However, I'm still unable to change nvram values for boot-args. Is there another security feature that I haven't disabled? ``` >sudo -i >csrutil status System Integrity Protection status: disabled. >nvram boot-args="amfi_get_out_of_my_way=0x1" nvram: Error setting variable - 'boot-args': (iokit/common) general error >nvram test=test >nvram test test test >nvram boot-args nvram: Error getting variable - 'boot-args': (iokit/common) data was not found

I have an M1 Mac Mini that is exhibiting some strange issues that aren't going away after reinstalling macOS. I'd like to reset its NVRAM or whatever the nearest equivalent is for M1 macs, in case something there is causing persistent problems. Are there equivalent steps to Intel Macs with T2 chips to reset things when the symptoms are not specific?

I'd like to set both vm_compression=1 plus serverperfmode=1. Can I achieve this by nvram boot-args "vm_compression=1","serverperfmode=1"