macOS 11 Big Sur on Unsupported Macs Thread

[jhowarth]

I just used this:

sudo mount -uw /
sudo chown -R 0:0 /System/Library/Extensions/
sudo chmod -R 755 /System/Library/Extensions/
sudo kextcache -i /
sudo kmutil install --update-all
sudo kcditto

Now that you have "sudo mount -uw /" I'd advise to remove the telemetry.plugin .

LegacyUSBInjector doesn't show on kextstat, only on System Report loaded Extensions with unknown signature and notarised no.

this is the prelinkedkernel for beta3 to boot legacy USB without CMD+S: https://forums.macrumors.com/thread...unsupported-macs-thread.2242172/post-28702758

Did you create any directories or symlinks beforehand to handle the missing Caches and PrelinkedKernels directories in /Library/Apple/System/Library. In my experience, 'sudo kextcache -i /' will spew an error at some point about not finding those (which existed in Catalina but not Big Sur). Perhaps upgrades from Catalina might leave the previous copies in place suppressing that error.

 

[jackluke]

Did you create any directories or symlinks beforehand to handle the missing Caches and PrelinkedKernels directories in /Library/Apple/System/Library.

No symlinks and no caches, with kextcache I get only many errors on AppleMobileFileIntegrity.kext and an error on AppleBSDKextStarter.kext .

But it worked anyway, about kmutil I guess if you want to build that kernelcache properly you need to remove the com.apple.Boot.plist on the BigSur Preboot volume that my script installed and disable the prelinkedkernel.

 

[eikic1]

Looks like the hax2 / hax3 patch was not carried out successfully. Try again and stick to the "recipe" as close as possible...

can you share me link thread??
thanks

 

[Barry K. Nathan]

The challenge now is to make work LegacyUSBInjector.kext on BaseSystem's BootKernelExtensions.kc , because seems there is no way to boot the BaseSystem Recovery environment with prelinkedkernel.

I haven't tried yet the @testheit kmutil method for LegacyUSBInjector.kext , but this might require some additional modification to the "macOS Base System" or its "Preboot".

You could also manual point a BKE on the USB BigSur Installer example attached.

It actually is possible to boot the BaseSystem with a prelinkedkernel. I just did it. (Basically, I used LZVN to extract all the kexts from the prelinkedkernel, then created a Zip archive of the System folder inside LZVN's kext output, then extracted that Zip archive at the root of the BaseSystem so that the kexts in that archive would overwrite the same kexts on the BaseSystem, but kexts on the BaseSystem that were never in the prelinkedkernel would be left alone.)

Part of what helped me figure out that this needed to be done, is that I managed to get a photo of the messages leading up to the kernel panic. I'm attaching that photo since it might be enlightening to others. (What's happening is something along the lines of launchd invoking mount_tmpfs, which tries to load tmpfs.kext, and that fails for some reason, so mount_tmpfs fails, so launchd triggers a kernel panic. I don't know why mount_tmpfs is trying to load tmpfs.kext when it's part of the prelinkedkernel.)

The unfortunate thing is, there's weird stuff going on with the kexts on the BaseSystem that seems to make it impossible to build either a prelinkedkernel or a BootKernelExtensions.kc from them. (Both kextcache and kmutil produce error messages that make basically no sense. I'm too exhausted right now to be more specific than that.)

I have ideas on what to try next. Basically, first I think I'll see if what I did with LZVN makes it possible to boot with a BootKernelExtensions.kc from a full Big Sur installation. If not, then maybe I'll try something like replacing the kexts in /System/Library/Extensions on the BaseSystem with the corresponding kexts from a full Big Sur install. (If all else fails, I'll try enlarging the BaseSystem.dmg and replacing /S/L/E on the BaseSystem with /S/L/E from full Big Sur.) It's possible that I won't get to try any of this until tomorrow.

A couple more notes:

You can actually copy a read-write (UDRW) image onto the USB stick (replacing BaseSystem.dmg) and use that as the root dmg. It will mount read-only, but a simple 'mount -uw /' in Terminal will mount it read-write. That's how I was able to try to build both a kc and a prelinkedkernel from inside BaseSystem.

One potentially neat thing to try is to add the launchd script from this StackOverflow post to the BaseSystem.dmg (but put it in /System/Library/LaunchDaemons, not /Library/LaunchDaemons, and change /etc/rc.local to just /rc.local). Then you can put a shell script called rc.local at the root of the BaseSystem (make sure to chmod it of course), and that script will run at some point during boot. It might not be how you would want to do things in an automated patcher, but it might be helpful during development.

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One other thing that I noticed on my Catalina machine was that the prelinked kernel doesn't show any obvious indications of LegacyUSBInjector.kext being embedded in it (ie grepping on parrot has no hits unlike with kc's).

I think you'll need to decompress the prelinkedkernel with something like LZVN before you can grep it.

 

[jackluke]

It actually is possible to boot the BaseSystem with a prelinkedkernel. I just did it. (Basically, I used LZVN to extract all the kexts from the prelinkedkernel, then created a Zip archive of the System folder inside LZVN's kext output, then extracted that Zip archive at the root of the BaseSystem so that the kexts in that archive would overwrite the same kexts on the BaseSystem, but kexts on the BaseSystem that were never in the prelinkedkernel would be left alone.)

I also booted the BaseSystem with legacy usb prelinkedkernel through CMD+S (just changing the kernel cache to prelinkedkernel with USB installer com.apple.Boot.plist), but it won't boot the graphical environment (same kp issue on tmpfs.kext).

I guess that recompressing with LZVN some kext and dictionary.plist won't produce a valid kernelcache ID (unless you use kextcache targeting that kexts folder and a BigSur kernel file) , this new BaseSystem with its Preboot it's weird, I guess more BKE with legacy usb if patched properly could boot the Recovery.

 

[Barry K. Nathan]

I also booted the BaseSystem with legacy usb prelinkedkernel with single user mode (just changing the kernel cache to prelinkedkernel with USB installer com.apple.Boot.plist), but it won't boot the graphical environment.

I don't think that recompressing with LZVN some kext and dictionary.plist produces a valid kernelcache ID .

I didn't do anything involving dictionary.plist. I didn't recompress anything with LZVN. And the result definitely booted into the graphical environment. I did not change the prelinkedkernel. I changed stuff in /System/Library/Extensions on the BaseSystem.

Maybe I should try to explain in more detail at some point -- but there was no way to use the result to build an updated prelinkedkernel, so it was a dead end that didn't help after all.

 

[jackluke]

I didn't do anything involving dictionary.plist. I didn't recompress anything with LZVN. And the result definitely booted into the graphical environment. I did not change the prelinkedkernel. I changed stuff in /System/Library/Extensions on the BaseSystem.

Do you booted BigSur Recovery graphical environment using the stock apple prelinkedkernel instead of BKE ?

Without modifying prelinkedkernel or BKE, a patched BaseSystem can also contain custom apps and will boot but only from a recent IOUSB Mac, and from my test using prelinkedkernel won't boot neither a stock BaseSystem .

Weirdly prelinkedkernel can boot a full BigSur installation but not its BaseSystem.dmg .

edit:
I guess I understood, you replaced the kexts (LZVN) contained in the prelinkedkernel on the /macOS Base System/SLE/ and this allowed to boot graphical Recovery using prelinkedkernel instead of BKE ? (Are you sure that wasn't targeted BKE as kernel cache?)

If so then it could be useful for further testing.

 

[Arnomacmini]

and here is another method https://github.com/nonforgettable/big-sur-automator

Thank you for this method . It works for me on Mac Mini Mi 2011 (5.1)
Wifi is working
sound via HDMI not working
Airdrop not working

Thank you for all, have you please an idea for HDMI sound and Airdrop ?
Thanks.

 

[MacHacJac]

Thank you for this method . It works for me on Mac Mini Mi 2011 (5.1)
Wifi is working
sound via HDMI not working
Airdrop not working

Thank you for all, have you please an idea for HDMI sound and Airdrop ?
Thanks.

How did you get it to work? I'm having loads of trouble in terminal because it says that my volume "is a directory"

 

[TimothyR734]

I haven't got it to work either so these are hit and miss foursome of us

 

[Arnomacmini]

How did you get it to work? I'm having loads of trouble in terminal because it says that my volume "is a directory"

Exactly as it says .

 

[iamprabhuantony]

I also booted the BaseSystem with legacy usb prelinkedkernel through CMD+S (just changing the kernel cache to prelinkedkernel with USB installer com.apple.Boot.plist), but it won't boot the graphical environment (same kp issue on tmpfs.kext).

I guess that recompressing with LZVN some kext and dictionary.plist won't produce a valid kernelcache ID (unless you use kextcache targeting that kexts folder and a BigSur kernel file) , this new BaseSystem with its Preboot it's weird, I guess more BKE with legacy usb if patched properly could boot the Recovery.

I followed your Method of Big Sur Beta Three Installation. Successfully Installed, unsealed. Please Guide me fix Wifi. IO80211Family.kext

 

[jackluke]

I followed your Method of Big Sur Beta Three Installation. Successfully Installed, unsealed. Please Guide me fix Wifi. IO80211Family.kext

Can you use from BigSur terminal : sudo mount -uw / ; killall Finder

and which machine do you have ?

Anyway, for Penryn Core2Duo try this: BigSur Penryn beta3 prelinkedkernel fix.command.zip

for Ivy Bridge (or Sandy Bridge too) : BigSur IvyBridge beta3 prelinkedkernel fix.command.zip

But I only included Broadcom Wifi cards drivers.

 

[jackluke]

@Barry K. Nathan if after replaced the /macOS Base System/SLE/ with the LZVN kexts decompressed from a BigSur prelinkedkernel and are using a prelinkedkernel "kernel cache" too from the USB BigSur Installer com.apple.Boot.plist , then you could try this: USBOpenCoreAPFSloader3b.app.zip

that should inject on any prelinkedkernel (even a stock apple one) the LegacyUSBInjector , and the patched BaseSystem.dmg should be bootable to graphical Recovery with responsive USB input output devices from a legacy USB Mac.

(But on that USBopencore setup I used w%08%00%00 as default csr-active-config so you need to use a patched ASentientBot 0xFFF boot.efi on the USB BigSur Installer to allow the patched BaseSystem to skip the "imageboot.c" kp )

Also I have another found about USB BigSur Installer beta3 (that I already tested and worked), you can use in this path /USBInstallerBigSur/BaseSystem/ even a BaseSystem.dmg (with its chunklist) from beta1 or beta2 (size 740 MB), while a beta3 is 884 MB , I mean the BigSur Recovery environment will boot correctly and install anyway the next BigSur beta3 because the "Install macOS" reference is outside of the BaseSystem (Ramdisk or Image Volume) that is the InstallAssistant (or InstallAssistant_springboard) exec on the root "Install macOS BigSur Beta.app/Contents/MacOS/" external to the BaseSystem , hence using a BaseSystem from beta1 or beta2 will work also for the beta3 installer .

This works because there is a second BaseSystem.dmg embedded in the SharedSupport.dmg that is unpackaged and used only during stage2 installer so there is no conflict with the /USBInstallerBigSur/BaseSystem/BaseSystem.dmg

Eventually could be used the same patched BaseSystem.dmg even for next BigSur beta releases.

 

[TimothyR734]

https://github.com/google/filament/issues/2876 I wish we could use something like this for example Maps or Garageband
Yes, we have a CMake flag to enable / disable to Metal backend: FILAMENT_SUPPORTS_METAL.

The CMAKE_OSX_DEPLOYMENT_TARGET flag can be used to force an older SDK version.

I'm able to disable Metal and build Filament for macOS 10.13 with the following:

cmake -G Ninja .. -DCMAKE_BUILD_TYPE=Release -DFILAMENT_SUPPORTS_METAL:BOOL=OFF -DCMAKE_OSX_DEPLOYMENT_TARGET=10.13
ninja

 

[jhowarth]

I just used this:

sudo mount -uw /
sudo chown -R 0:0 /System/Library/Extensions/
sudo chmod -R 755 /System/Library/Extensions/
sudo kextcache -i /
sudo kmutil install --update-all
sudo kcditto

Now that you have "sudo mount -uw /" I'd advise to remove the telemetry.plugin .

LegacyUSBInjector doesn't show on kextstat, only on System Report loaded Extensions with unknown signature and notarised no.

this is the prelinkedkernel for beta3 to boot legacy USB without CMD+S: https://forums.macrumors.com/thread...unsupported-macs-thread.2242172/post-28702758

With 'sudo kmutil install --update-all', do you see this error?

rebuilding release collections: boot, system
rebuilding release collections:
    boot kernel collection
    system kext collection
rebuilding local auxiliary collection
Error: Error Domain=NSCocoaErrorDomain Code=4097 "connection to service on pid 0 named com.apple.KernelExtensionServer" UserInfo={NSDebugDescription=connection to service on pid 0 named com.apple.KernelExtensionServer}

Actually, if I remove the Caches symlink that I added into /Library/Apple/System/Library to point at /System/Library/Caches, I get this...

Can't read info dictionary for /Library/Apple/System/Library/Extensions/AppleMobileDevice.kext: IOCFUnserialize: syntax error near line 1.
Can't read info dictionary for /Library/Apple/System/Library/Extensions/AppleMobileDevice.kext: IOCFUnserialize: syntax error near line 1.
Can't read info dictionary for /Library/Apple/System/Library/Extensions/AppleMobileDevice.kext: IOCFUnserialize: syntax error near line 1.
Can't read info dictionary for /Library/Apple/System/Library/Extensions/AppleMobileDevice.kext: IOCFUnserialize: syntax error near line 1.
Can't read info dictionary for /Library/Apple/System/Library/Extensions/AppleMobileDevice.kext: IOCFUnserialize: syntax error near line 1.
Kext with invalid signature (-67062) allowed: <OSKext 0x7ff8c58b1fe0 [0x7fff86151c20]> { URL = "file:///System/Library/Extensions/LegacyUSBInjector.kext/", ID = "com.parrotgeek.LegacyUSBInjector" }
/System/Library/Extensions/AppleBSDKextStarter.kext doesn't support architecture x86_64; omitting from prelinked kernel.
KernelCache ID: 5D249C976F04F76D5AE9B83505AF8DE7
symlink("../../../PrelinkedKernels/prelinkedkernel", "/Library/Apple/System/Library/Caches/com.apple.kext.caches/Startup/kernelcache") failed 2 (No such file or directory)
Can't read info dictionary for /Library/Apple/System/Library/Extensions/AppleMobileDevice.kext: IOCFUnserialize: syntax error near line 1.
Can't read info dictionary for /Library/Apple/System/Library/Extensions/AppleMobileDevice.kext: IOCFUnserialize: syntax error near line 1.
Can't read info dictionary for /Library/Apple/System/Library/Extensions/AppleMobileDevice.kext: IOCFUnserialize: syntax error near line 1.
Kext with invalid signature (-67062) allowed: <OSKext 0x7fbb3d787e20 [0x7fff86151c20]> { URL = "file:///System/Library/Extensions/LegacyUSBInjector.kext/", ID = "com.parrotgeek.LegacyUSBInjector" }
Can't read info dictionary for /Library/Apple/System/Library/Extensions/AppleMobileDevice.kext: IOCFUnserialize: syntax error near line 1.
Can't read info dictionary for /Library/Apple/System/Library/Extensions/AppleMobileDevice.kext: IOCFUnserialize: syntax error near line 1.
Can't read info dictionary for /Library/Apple/System/Library/Extensions/AppleMobileDevice.kext: IOCFUnserialize: syntax error near line 1.

which is the error I was talking about originally....

symlink("../../../PrelinkedKernels/prelinkedkernel", "/Library/Apple/System/Library/Caches/com.apple.kext.caches/Startup/kernelcache") failed 2 (No such file or directory)

 

[EdGlassgow]

I installed OpenCore on my MacPro 5,1, mainly to facilitate switching between Mojave and Catalina as I have a couple of apps that I needs to use that are not 64-bit. I want to experiment with Big Sur and have created USB installers using both the ParrotGeek method and the MicroPatcher method. When the machine boots, it shows the installer USB and it appears to start to boot, but then reboots and presents the OpenCore boot menu. Is there something special that I need to do to get a USB installer to boot when running OpenCore? Sorry if this is a silly question!

 

[Ronald Steven]

@TimothyR734[/USER] this method works on a map mid 2012 and bs beta3? https://www.reddit.com/r/BigSurPatcher/comments/hyzo74
i had installed BS 2 and wifi and audio works fine, but when I connect my AirPods the sound is so bad, any solution for that?

 

[Barry K. Nathan]

I guess I understood, you replaced the kexts (LZVN) contained in the prelinkedkernel on the /macOS Base System/SLE/ and this allowed to boot graphical Recovery using prelinkedkernel instead of BKE ? (Are you sure that wasn't targeted BKE as kernel cache?)

If so then it could be useful for further testing.

Yes. And I am sure I did not use BKE by accident -- a lot of the messages in verbose boot are very visibly different when booting from the prelinkedkernel.
[automerge]1596061745[/automerge]

Thank you for this method . It works for me on Mac Mini Mi 2011 (5.1)
Wifi is working
sound via HDMI not working
Airdrop not working

Thank you for all, have you please an idea for HDMI sound and Airdrop ?
Thanks.

Repeat "Kext Patch like a charm [Optional]", but in step 3, where it says to type "/Volumes/Image\ Volume/patch-kexts.sh /Volumes/", type "/Volumes/Image\ Volume/patch-kexts.sh --2011 /Volumes/" instead. Hopefully that will give you sound via HDMI.

In general, these projects to add further automation on top of my micropatcher, if you follow their steps exactly, are (currently) only going to fully work on 2012/2013 Macs. (Edit: These projects may have typos or bugs in them, but I don't have time to test them myself and need to stay focused on improving my patcher.) Step 9 of the README for my patcher isn't joking about the extra command line parameters for older Macs.

One of the features I was originally going to add to my patcher this week was automatic detection of Mac model in step 9, so that the extra command line parameter becomes optional, but with the time I've been spending on manipulating BaseSystem.dmg, that (and also being able to do step 9 without having to start up from the installer USB first) may have to wait until next week. (Or maybe I'll still be able to get it done this week. We'll see...)

 

[Barry K. Nathan]

@Barry K. Nathan if after replaced the /macOS Base System/SLE/ with the LZVN kexts decompressed from a BigSur prelinkedkernel and are using a prelinkedkernel "kernel cache" too from the USB BigSur Installer com.apple.Boot.plist , then you could try this: USBOpenCoreAPFSloader3b.app.zip

that should inject on any prelinkedkernel (even a stock apple one) the LegacyUSBInjector , and the patched BaseSystem.dmg should be bootable to graphical Recovery with responsive USB input output devices from a legacy USB Mac.

(But on that USBopencore setup I used w%08%00%00 as default csr-active-config so you need to use a patched ASentientBot 0xFFF boot.efi on the USB BigSur Installer to allow the patched BaseSystem to skip the "imageboot.c" kp )

Also I have another found about USB BigSur Installer beta3 (that I already tested and worked), you can use in this path /USBInstallerBigSur/BaseSystem/ even a BaseSystem.dmg (with its chunklist) from beta1 or beta2 (size 740 MB), while a beta3 is 884 MB , I mean the BigSur Recovery environment will boot correctly and install anyway the next BigSur beta3 because the "Install macOS" reference is outside of the BaseSystem (Ramdisk or Image Volume) that is the InstallAssistant (or InstallAssistant_springboard) exec on the root "Install macOS BigSur Beta.app/Contents/MacOS/" external to the BaseSystem , hence using a BaseSystem from beta1 or beta2 will work also for the beta3 installer .

This works because there is a second BaseSystem.dmg embedded in the SharedSupport.dmg that is unpackaged and used only during stage2 installer so there is no conflict with the /USBInstallerBigSur/BaseSystem/BaseSystem.dmg

Eventually could be used the same patched BaseSystem.dmg even for next BigSur beta releases.

I'll try USBOpenCoreAPFSloader3b + prelinkedkernel tonight.

 

[guerrabadboy]

Hi, yes, my disk is encrypted with FileVault. However, it was encrypted when I (a) installed Big Sur Beta 1 on top of Catalina; (b) upgraded from Beta 1 to Beta 2, and from Beta 2 to Beta 3 (which I am currently using): in those cases, I had no issue at all when I was requested to enter my password (BTW, I used my login password). The problem has shown up only three days ago, when after a successful upgrade to Beta 3 I rebooted into the installer to perform step 9 in order to fix the WiFi. It's really strange. Attached are two photos of my Retina MBP with password request. Thanks! P.S.: I know, my MBP has the StainGate!

Did you fix it??
I also have the same problem as you? (also I did upgrade from catalina to Big Sur beta 1, then update to beta 2 and beta 3)

 

[Arnomacmini]

Yes. And I am sure I did not use BKE by accident -- a lot of the messages in verbose boot are very visibly different when booting from the prelinkedkernel.
[automerge]1596061745[/automerge]

Repeat "Kext Patch like a charm [Optional]", but in step 3, where it says to type "/Volumes/Image\ Volume/patch-kexts.sh /Volumes/", type "/Volumes/Image\ Volume/patch-kexts.sh --2011 /Volumes/" instead. Hopefully that will give you sound via HDMI.

In general, these projects to add further automation on top of my micropatcher, if you follow their steps exactly, are (currently) only going to fully work on 2012/2013 Macs. (Edit: These projects may have typos or bugs in them, but I don't have time to test them myself and need to stay focused on improving my patcher.) Step 9 of the README for my patcher isn't joking about the extra command line parameters for older Macs.

One of the features I was originally going to add to my patcher this week was automatic detection of Mac model in step 9, so that the extra command line parameter becomes optional, but with the time I've been spending on manipulating BaseSystem.dmg, that (and also being able to do step 9 without having to start up from the installer USB first) may have to wait until next week. (Or maybe I'll still be able to get it done this week. We'll see...)

Hello and thank you for your help.
I tried exactly like you said I have Wifi correctly but, no Ethernet , no Sound via HDMI , , No Airdrop .
Any idea ?

 

[jhowarth]

This is the complete output that I am seeing for a prelinkedkernel build which still produces the Bluetooth keyboard dialog instead of usable legacy usb support...

% sudo mount -uw /
% sudo chown -R 0:0 /System/Library/Extensions/
% sudo chmod -R 755 /System/Library/Extensions/
% sudo kextcache -i /
Can't read info dictionary for /Library/Apple/System/Library/Extensions/AppleMobileDevice.kext: IOCFUnserialize: syntax error near line 1.
Can't read info dictionary for /Library/Apple/System/Library/Extensions/AppleMobileDevice.kext: IOCFUnserialize: syntax error near line 1.
Can't read info dictionary for /Library/Apple/System/Library/Extensions/AppleMobileDevice.kext: IOCFUnserialize: syntax error near line 1.
Can't read info dictionary for /Library/Apple/System/Library/Extensions/AppleMobileDevice.kext: IOCFUnserialize: syntax error near line 1.
Can't read info dictionary for /Library/Apple/System/Library/Extensions/AppleMobileDevice.kext: IOCFUnserialize: syntax error near line 1.
Kext with invalid signature (-67062) allowed: <OSKext 0x7f8d1850ef30 [0x7fff83ea5c20]> { URL = "file:///Library/Extensions/LegacyUSBInjector.kext/", ID = "com.parrotgeek.LegacyUSBInjector" }
/System/Library/Extensions/AppleBSDKextStarter.kext doesn't support architecture x86_64; omitting from prelinked kernel.
KernelCache ID: 5D249C976F04F76D5AE9B83505AF8DE7
symlink("../../../PrelinkedKernels/prelinkedkernel", "/Library/Apple/System/Library/Caches/com.apple.kext.caches/Startup/kernelcache") failed 2 (No such file or directory)
Can't read info dictionary for /Library/Apple/System/Library/Extensions/AppleMobileDevice.kext: IOCFUnserialize: syntax error near line 1.
Can't read info dictionary for /Library/Apple/System/Library/Extensions/AppleMobileDevice.kext: IOCFUnserialize: syntax error near line 1.
Can't read info dictionary for /Library/Apple/System/Library/Extensions/AppleMobileDevice.kext: IOCFUnserialize: syntax error near line 1.
Kext with invalid signature (-67062) allowed: <OSKext 0x7fc827af6070 [0x7fff83ea5c20]> { URL = "file:///Library/Extensions/LegacyUSBInjector.kext/", ID = "com.parrotgeek.LegacyUSBInjector" }
Can't read info dictionary for /Library/Apple/System/Library/Extensions/AppleMobileDevice.kext: IOCFUnserialize: syntax error near line 1.
Can't read info dictionary for /Library/Apple/System/Library/Extensions/AppleMobileDevice.kext: IOCFUnserialize: syntax error near line 1.
Can't read info dictionary for /Library/Apple/System/Library/Extensions/AppleMobileDevice.kext: IOCFUnserialize: syntax error near line 1.
% sudo kmutil install --update-all
checking collections...
unable to load existing release kernel collections, forcing rebuild
rebuilding release collections: boot, system
rebuilding release collections:
    boot kernel collection
    system kext collection
rebuilding local auxiliary collection
Error: Error Domain=NSCocoaErrorDomain Code=4097 "connection to service on pid 0 named com.apple.KernelExtensionServer" UserInfo={NSDebugDescription=connection to service on pid 0 named com.apple.KernelExtensionServer}
% sudo kcditto
Copying deferred prelinked kernels in /...
Copying: /Library/Apple/System/Library/PrelinkedKernels/prelinkedkernel -> /System/Library/PrelinkedKernels
Copying KCs in /...
System Volume UUID: CF2D53BB-9152-45FA-BF0E-4E8B2FD8F30F
Volume Group UUID: 13982718-DA24-480A-9EDD-51D4FBB809A5
Preboot disk: /dev/disk8s2
Preboot volume: /System/Volumes/Preboot
Copying: /System/Library/KernelCollections/BootKernelExtensions.kc.elides -> /System/Volumes/Preboot/13982718-DA24-480A-9EDD-51D4FBB809A5/boot/System/Library/KernelCollections
Copying: /System/Library/KernelCollections/BootKernelExtensions.kc -> /System/Volumes/Preboot/13982718-DA24-480A-9EDD-51D4FBB809A5/boot/System/Library/KernelCollections
Copying: /System/Library/PrelinkedKernels/immutablekernel -> /System/Volumes/Preboot/13982718-DA24-480A-9EDD-51D4FBB809A5/System/Library/PrelinkedKernels
Copying: /System/Library/PrelinkedKernels/prelinkedkernel -> /System/Volumes/Preboot/13982718-DA24-480A-9EDD-51D4FBB809A5/System/Library/PrelinkedKernels
%

Is there anything in there that is obviously different?

 

[Barry K. Nathan]

Hello and thank you for your help.
I tried exactly like you said I have Wifi correctly but, no Ethernet , no Sound via HDMI , , No Airdrop .
Any idea ?

I'll try to investigate this when I get a chance.

By the way, does audio over HDMI work under Mojave or Catalina on your Mac Mini?

 

[Barry K. Nathan]

So I tried USBOpenCoreAPFSloader3b + prelinkedkernel.

On my MacBook6,1 it works! It boots the Big Sur beta 3 USB stick, patched as I previously described to use the prelinkedkernel, and the keyboard and trackpad work! It got as far as the FileVault account prompt (my MacBook6,1 has a FileVault-encrypted Mojave running on the internal drive), but I decided to shut down instead of proceeding further. Unfortunately, it seems like my boot-args and csr-active-config got cleared from nvram. This is my first time trying OpenCore, so I don't know if this is expected. (I tried it a second time and they got cleared a second time, by the way.) So I'll still see if I can get an updated BKE to work on the Big Sur installer USB.

By the way, on my MacBook4,1 (I may not have previously mentioned that I have one), it flashes between the Apple logo and the prohibited sign, and eventually seems to freeze up, before it ever gets to the OpenCore boot menu. (I don't actually care that much about getting my MacBook4,1 to run Big Sur, but I figured I'd give it a quick try. Right now it's still on Lion.)