I'm trying to install the KDK package on a VM with BigSur 11.1 on it (20C69 build). I used Apple's guide for general guidelines, and this guide for details.

  • It appears that since Catalina, the system volume is read-only:
  • Indeed, after disabling SIP in recovery mode, trying to copy kernel.development to /System/Library/Kernels results in an error message saying: "Operation Not Permitted".

Some forums suggested to mount it as writeable and save the changes, for example here:

  • The command csrutil authenticated-root disable is not recognized for some reason, and shows the csrutil help text.
  • If using the "regular" csrutil disable, then back in the normal boot mode csrutil status indicates that all of the components are disabled, apart from BaseSystem Verification which is still enabled.
  • Attempting to ignore it and move forward with the instructions, everything goes smoothly until the bless command, which fails with the same "Operation Not Permitted".

So far no luck with any of the similar guides (1,2...) as well.

Would appreciate any help,


2 Answers 2


I believe what Jichao was trying to clarify for the original question is that changes to the System Integrity Protection (SIP) in macOS can only be made in recovery mode (and possibly in Single User mode but I have never tried it and am only guessing). This has always been true to the best of my knowledge as a Mac user and applies to whether you are using:

csrutil enable/disable csrutil authenticated-root disable/enable

however if my read of the user's issue is correct, this was done in recovery mode and still generated the "Operation not permitted" error.

To anyone reading this and facing a similar issue, my suggestion would be to mount the drive as root from single user mode with full read & write privileges and copy the kernel.development file into the intended directory manually.

You might also be able to gain access while in macOS either through Target Disk Mode from another Mac or using the "Get Info" command in Finder of the Mac you are using to edit your privileges and take ownership of the drive as a system administrator and then paste the file directly. I don't recommend this because it could change how some essential systems are able to function and screw up your machine, especially if you do not immediately do a full permissions repair before rebooting.


Can I mount the root (system) filesystem as writable in Big Sur? do works.

csrutil authenticated-root disable should executed in recovery mode.

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