macOS 11 Big Sur on Unsupported Macs Thread

[Toledospod]

Hi everyone,

Newbie here on the forum, but not new to beta testing and the such (also a super computer nerd!).

I have a iMac late 2013 that I just installed from scratch with the latest beta and Barry's Micropatcher (in fact I'm posting from inside the beta right now). Haven't tested everything yet, but it worked as expected after I got past the same issue someone else had on here a few pages back - the NVRAM error "nvram error getting variable -boot-args (iokit/common) data was not found". I believe it was in post #3,805.

When I first tried to install this morning, I kept running into the above error message after I created the bootable USB drive and patched it using Barry's Micropatcher and then booted from the USB drive. The next instructions to run 'set-vars.sh' from terminal is where I had issues. I kept getting the "nvram error getting variable -boot-args (iokit/common) data was not found", even though it successfully disabled SIP, etc. Thinking that I could just ignore this, I tried to install MacOS Big Sur Beta (Beta 6) and it kept giving me the Forbidden symbol after it rebooted the first time (having dowloaded the additional components).

I tried to understand what everyone else on here has been commenting in this thread, but it wasn't helping my issue, so I searched the interwebs for an answer. Not sure if I'm allowed to post what I found on here, but what I found is that there is a step that might need to be done in-between patching the USB installer and booting from it. Essentially, there was an addtional step of booting into Recovery Mode (NOT from the USB drive), opening terminal and running the following command:

nvram boot-args=-no_compact_check

Then, restart and boot from the USB installer, open Terminal again and run -

/Volumes/Image\ Volume/set-vars.sh

. Then, install MacOS Big Sur and it should restart and continue as expected after downloading the additional components.

So, apparently the 'no_compact_check' is crucial to prevent the 'Forbidden' symbol coming up after you start the install and this command HAS to be run from regular MacOS Recovery and NOT from the USB installer. As I understand it, Beta 6 broke the 'NVRAM boot-args' command that is supposed built into Barry's Micropatcher (though I could be wrong about this), hence why you have to run this command before booting from the USB installer.

Hope this helps Will350 and anyone else that's had this issue recently!

 

[botellon]

Hi everyone,

Newbie here on the forum, but not new to beta testing and the such (also a super computer nerd!).

I have a iMac late 2013 that I just installed from scratch with the latest beta and Barry's Micropatcher (in fact I'm posting from inside the beta right now). Haven't tested everything yet, but it worked as expected after I got past the same issue someone else had on here a few pages back - the NVRAM error "nvram error getting variable -boot-args (iokit/common) data was not found". I believe it was in post #3,805.

When I first tried to install this morning, I kept running into the above error message after I created the bootable USB drive and patched it using Barry's Micropatcher and then booted from the USB drive. The next instructions to run 'set-vars.sh' from terminal is where I had issues. I kept getting the "nvram error getting variable -boot-args (iokit/common) data was not found", even though it successfully disabled SIP, etc. Thinking that I could just ignore this, I tried to install MacOS Big Sur Beta (Beta 6) and it kept giving me the Forbidden symbol after it rebooted the first time (having dowloaded the additional components).

I tried to understand what everyone else on here has been commenting in this thread, but it wasn't helping my issue, so I searched the interwebs for an answer. Not sure if I'm allowed to post what I found on here, but what I found is that there is a step that might need to be done in-between patching the USB installer and booting from it. Essentially, there was an addtional step of booting into Recovery Mode (NOT from the USB drive), opening terminal and running the following command:



Then, restart and boot from the USB installer, open Terminal again and run - . Then, install MacOS Big Sur and it should restart and continue as expected after downloading the additional components.

So, apparently the 'no_compact_check' is crucial to prevent the 'Forbidden' symbol coming up after you start the install and this command HAS to be run from regular MacOS Recovery and NOT from the USB installer. As I understand it, Beta 6 broke the 'NVRAM boot-args' command that is supposed built into Barry's Micropatcher (though I could be wrong about this), hence why you have to run this command before booting from the USB installer.

Hope this helps Will350 and anyone else that's had this issue recently!

This seems to be the solution I was looking for, however because I already wiped my system drive I only get internet recovery which doesn't seem to work. I'll try to reinstall Catalina, create a patched USB again and then change boot-args in recovery before installing.

 

[Will350]

Hi everyone,

Newbie here on the forum, but not new to beta testing and the such (also a super computer nerd!).

I have a iMac late 2013 that I just installed from scratch with the latest beta and Barry's Micropatcher (in fact I'm posting from inside the beta right now). Haven't tested everything yet, but it worked as expected after I got past the same issue someone else had on here a few pages back - the NVRAM error "nvram error getting variable -boot-args (iokit/common) data was not found". I believe it was in post #3,805.

When I first tried to install this morning, I kept running into the above error message after I created the bootable USB drive and patched it using Barry's Micropatcher and then booted from the USB drive. The next instructions to run 'set-vars.sh' from terminal is where I had issues. I kept getting the "nvram error getting variable -boot-args (iokit/common) data was not found", even though it successfully disabled SIP, etc. Thinking that I could just ignore this, I tried to install MacOS Big Sur Beta (Beta 6) and it kept giving me the Forbidden symbol after it rebooted the first time (having dowloaded the additional components).

I tried to understand what everyone else on here has been commenting in this thread, but it wasn't helping my issue, so I searched the interwebs for an answer. Not sure if I'm allowed to post what I found on here, but what I found is that there is a step that might need to be done in-between patching the USB installer and booting from it. Essentially, there was an addtional step of booting into Recovery Mode (NOT from the USB drive), opening terminal and running the following command:



Then, restart and boot from the USB installer, open Terminal again and run - . Then, install MacOS Big Sur and it should restart and continue as expected after downloading the additional components.

So, apparently the 'no_compact_check' is crucial to prevent the 'Forbidden' symbol coming up after you start the install and this command HAS to be run from regular MacOS Recovery and NOT from the USB installer. As I understand it, Beta 6 broke the 'NVRAM boot-args' command that is supposed built into Barry's Micropatcher (though I could be wrong about this), hence why you have to run this command before booting from the USB installer.

Hope this helps Will350 and anyone else that's had this issue recently!

It works!!!Thank you so much

 

[highvoltage12v]

The "unknown special file or system" message has been addressed in one of the previous posts in this thread.
Attached is a copy of the response which solved this message problem.
Please note, that credit for this workaround belongs to the original author of the excerpt I included in the post.

You do have to identify the disk ID on your drive and substitute for the "disk2s5" entry. Hope this may be of help.

From USB BS Installer Recovery Terminal:
diskutil mount disk2s5
Volume Big Sur on disk2s5 mounted

terminal command ==> mount -uw /Volumes/Big\ Sur/.
system response ==> mount: unknown special file or file system /Volumes/Big Sur/.

Workaround (message):

Regarding the "unknown special file or file system" issue,
I had the same issue. However it did work for me when I put the path within quotation marks.
mount -uw "/Volumes/Big Sur"

No, nothing is working, coming from a fresh install. I'm spending way to much time on this.

 

[RogueB]

No, nothing is working, coming from a fresh install. I'm spending way to much time on this.

On previous installations (Not Beta 6) just putting the name of the drive in quotations, rather than the whole pathway, seem to work as well. (?)

I tried to install Beta 6 onto a clean partition, but had no luck.

Interestingly, upon booting into Big Sur in Single User mode, and just before all activity stalled, a line of text appeared which I have not seen before (during the boot process). See below:

***ConsiderRebulidOFPrelinkedKernel com.Apple.AppleUserHIDDrivers TriggeredRebuilding***

Given that I used Jackluke's penry prelinked kernel, such output line may imply that during installation process, the system checks PrelinkedKernels for "validity", and finding it lacking, rebuilds the kernels (?) The boot stalls just after that line; it's just a guess.

Has anyone succeeded in installing Big Sur Beta 6 on legacy Penryn (Core 2 Duo) machines?

 

[Danvan]

dosdude when will you be releasing the patcher tool? I would love to try the beta of macOS Big Sur on emu 2010 iMac with my new gpu geforces gtx 765M. I hope it going to work for the new macOS Big sur.

 

[justperry]

This seems to be the solution I was looking for, however because I already wiped my system drive I only get internet recovery which doesn't seem to work. I'll try to reinstall Catalina, create a patched USB again and then change boot-args in recovery before installing.

It works!!!Thank you so much

Good it works, keep in mind though that even if you don't have a recovery partition you could still use Internet recovery by holding the CMD + Option + R instead of normal recovery with CMD + R key combination, this though does not work on (Very) old machines without the correct Firmware, I don't know from what year Macs supports this feature.

https://support.apple.com/en-us/HT201314

 

[jackluke]

No, nothing is working, coming from a fresh install. I'm spending way to much time on this.

I guess from that environment is case sensitive, try mount -uw /Volumes/SUR or mount -uw /Volumes/SUR/

 

[jackluke]

Given that I used Jackluke's penry prelinked kernel, such output line may imply that during installation process, the system checks PrelinkedKernels for "validity", and finding it lacking, rebuilds the kernels (?) The boot stalls just after that line; it's just a guess.

Has anyone succeeded in installing Big Sur Beta 6 on legacy Penryn (Core 2 Duo) machines?

Using previous prelinkedkernel allows to boot beta 6 single user mode, also process all the verbose lines till the graphics kext, but without stage2 apple logo booting.

Instead making a prelinkedkernel with newer beta 6 kext (this required an unsealed without snapshot booting BigSur), after reboot gives on verbose lines "busy timeout" probably due to HID drivers.

Since the "BaseSystem legacy usb fix" still worked, I guessed to use the 240 beta3 kext also on a full beta 6 install, anyway using the micropatcher from a "BaseSystem legacy usb fixed" BigSur installer environment should allow to rebuild a BootKernelExtensions.kc , in that way legacy usb Mac could boot with CMD+S and "exit".

In some cases also using the USBOpenCoreAPFSloader4 should allow to boot with CMD+S and "exit", but you need first a valid BootKernelExtensions.kc for your machine.

 

[jackluke]

Though this may seem a bit off-topic meanwhile -
On my MBP5,2, a legacyUSB machine, continued installation exercises without resorting to SATA for the BS disk.
Did this with BS PB1 because I had no success with newer versions on that machine.

So I was able to install and boot PB1 using the on-board USB2 plus the USB3 on nanoTECH ExpressCard. Exactly the way @Larsvonhier has described in an earlier post: start booting on USB2, when it hangs due to legacyUSB support not (yet) in place, hot-swap to USB3, and it continues.

May sound complicated, but is easier and healthier than opening the machine to swap disks between SATA and USB.

It would be nice to boot directly from expresscard USB3 ports, without starting on USB2. Maybe there is a way with Opencore.

In few words legacy usb Mac can boot (after removed the telemetry plugin) even without responsive usb input devices from a SATA disk BigSur installation, while they stuck at early booting when the installation is on an external USB disk, using your method of hotswap USB3 wakes the usb unpowered, so at this point you could try to use the micropatcher for BootKernelExtensions.kc , only thing is that you should plug an USB external keyboard or mouse to the USB3 express card and of course using CMD+S and "exit" to continue booting.

The advantage of prelinkedkernel (from beta5 doesn't work more) was that you could use a common one for many machines, instead the BKE requires to rebuild kernelcollections directly from the target machine, an enough easy way to rebuild them is using the micropatcher that you can combine with "BaseSystem legacy usb fix" .

 

[thatsmeonlyme]

dosdude when will you be releasing the patcher tool? I would love to try the beta of macOS Big Sur on emu 2010 iMac with my new gpu geforces gtx 765M. I hope it going to work for the new macOS Big sur.

stand up and try to get what is available. work with it!

 

[MacPeet]

update report for my MacPro3,1 still positive
DP6 no problems here, everything works

 

[MacHacJac]

I guess from that environment is case sensitive, try mount -uw /Volumes/SUR or mount -uw /Volumes/SUR/

Jackluke! You're back!

 

[highvoltage12v]

I guess from that environment is case sensitive, try mount -uw /Volumes/SUR or mount -uw /Volumes/SUR/

When I do a simple "ls /Volumes/Sur" it can show me all the directories perfectly. Diskutility (recovery) lists /SUR as being a read only partition, which means hax v3 Isn't working correctly. I've tried different versions of @Barry K. Nathan micropatcher from 0.1.0/0.0.20/0.0.19 as someone on here mentioned go use an older version for B6. I'll look into this again later this evening. Thanks @jackluke

 

[thielsa]

Thanks for the positive feedback on MacPro 5.1 . I just reinstalled the latest beta as a fresh install and did not restore a Time Machine backup. So far things are running smooth.

 

[botellon]

Good it works, keep in mind though that even if you don't have a recovery partition you could still use Internet recovery by holding the CMD + Option + R instead of normal recovery with CMD + R key combination, this though does not work on (Very) old machines without the correct Firmware, I don't know from what year Macs supports this feature.

https://support.apple.com/en-us/HT201314

I tried that last night, after connecting to Wi-Fi and waiting for some time I get error -2002F, I'm using a MBP9,2, so no such luck. I'm creating a Catalina usb drive right now but TransMac is painfully slow.

 

[IbrahimFmc]

I tried that last night, after connecting to Wi-Fi and waiting for some time I get error -2002F, I'm using a MBP9,2, so no such luck. I'm creating a Catalina usb drive right now but TransMac is painfully slow.

you have to try Ethernet cable instead of wifi , because you have problem with your internet , also if you reset your internet modem maybe will fix internet connection

 

[Armere Caruso]

Okay I got Big Sur downloaded I’m on step after I hold cmd q for the reboot and it keeps not letting me put mount -uw I was not able to do the kext someone help and thank you for all those who got me to this point and it says mount: unknown special file or files system /volumes\bigsur

 

[Enrico Ferro]

You are right... I did it queen i first installed Big Sur beta 1 and then i forgot i did it!
Some days ago i repaired the disk permission and yesterday i updated to last Catalina version... So something has reset that pre-requisite...

Now i disabled the compact check form recovery terminal, ad you said, and everything work again...
Thanks...

IT WOULD BE USEFULL FOR ID NEWBIE IF
IF BARRY COULD UPDATE THE INSTRUCTIONS ON GITHUB MICROPATCHER PAGE REGARD THE PRE STEPS...

Hi everyone,

Newbie here on the forum, but not new to beta testing and the such (also a super computer nerd!).

I have a iMac late 2013 that I just installed from scratch with the latest beta and Barry's Micropatcher (in fact I'm posting from inside the beta right now). Haven't tested everything yet, but it worked as expected after I got past the same issue someone else had on here a few pages back - the NVRAM error "nvram error getting variable -boot-args (iokit/common) data was not found". I believe it was in post #3,805.

When I first tried to install this morning, I kept running into the above error message after I created the bootable USB drive and patched it using Barry's Micropatcher and then booted from the USB drive. The next instructions to run 'set-vars.sh' from terminal is where I had issues. I kept getting the "nvram error getting variable -boot-args (iokit/common) data was not found", even though it successfully disabled SIP, etc. Thinking that I could just ignore this, I tried to install MacOS Big Sur Beta (Beta 6) and it kept giving me the Forbidden symbol after it rebooted the first time (having dowloaded the additional components).

I tried to understand what everyone else on here has been commenting in this thread, but it wasn't helping my issue, so I searched the interwebs for an answer. Not sure if I'm allowed to post what I found on here, but what I found is that there is a step that might need to be done in-between patching the USB installer and booting from it. Essentially, there was an addtional step of booting into Recovery Mode (NOT from the USB drive), opening terminal and running the following command:



Then, restart and boot from the USB installer, open Terminal again and run - . Then, install MacOS Big Sur and it should restart and continue as expected after downloading the additional components.

So, apparently the 'no_compact_check' is crucial to prevent the 'Forbidden' symbol coming up after you start the install and this command HAS to be run from regular MacOS Recovery and NOT from the USB installer. As I understand it, Beta 6 broke the 'NVRAM boot-args' command that is supposed built into Barry's Micropatcher (though I could be wrong about this), hence why you have to run this command before booting from the USB installer.

Hope this helps Will350 and anyone else that's had this issue recently!

u are

 

[justperry]

I tried that last night, after connecting to Wi-Fi and waiting for some time I get error -2002F, I'm using a MBP9,2, so no such luck. I'm creating a Catalina usb drive right now but TransMac is painfully slow.

Should work, I have that same MBP here, try wired network as the poster below you suggested.

Okay I got Big Sur downloaded I’m on step after I hold cmd q for the reboot and it keeps not letting me put mount -uw I was not able to do the kext someone help and thank you for all those who got me to this point and it says mount: unknown special file or files system /volumes\bigsur

Should be /Volumes/bigsur ...that is, if the name has no space inbetween big and sur.

 

[botellon]

Should work, I have that same MBP here, try wired network as the poster below you suggested.



Should be /Volumes/bigsur ...that is, if the name has no space inbetween big and sur.

How long did it take for you to download the utilities?

 

[n0rt0nthecat]

I have a late 2013 iMac (21.5") which installed public beta 2 on an external SSD drive for testing. Seems to work fine using the micropatcher.

I'm wondering what the normal process might be going ahead for doing updates to the the systems using this method once it goes GA and point releases are done. Will they work from system updates app or will we need to do a bodgy job using a USB install etc??

Also, what would be the upgrade process from PB2 to PB3 when released?

 

[Toledospod]

You are right... I did it queen i first installed Big Sur beta 1 and then i forgot i did it!
Some days ago i repaired the disk permission and yesterday i updated to last Catalina version... So something has reset that pre-requisite...

Now i disabled the compact check form recovery terminal, ad you said, and everything work again...
Thanks...

IT WOULD BE USEFULL FOR ID NEWBIE IF
IF BARRY COULD UPDATE THE INSTRUCTIONS ON GITHUB MICROPATCHER PAGE REGARD THE PRE STEPS...



u are

Glad this worked for you as well!

I agree that it would be useful if the instructions were updated. Perhaps Barry will update soon. I don't if he looks at this website or this thread.

 

[Fauxly]

Also, what would be the upgrade process from PB2 to PB3 when released?

Where can I download beta 2 or beta 3?

 

[IbrahimFmc]

I have a late 2013 iMac (21.5") which installed public beta 2 on an external SSD drive for testing. Seems to work fine using the micropatcher.

I'm wondering what the normal process might be going ahead for doing updates to the the systems using this method once it goes GA and point releases are done. Will they work from system updates app or will we need to do a bodgy job using a USB install etc??

Also, what would be the upgrade process from PB2 to PB3 when released?

unsupported mac every update will require the same process , every update will create patched installer