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StarPlayrX
Prohibition sign when rebooting Mac Po 5.1 Mid 2010
Hello guys, I successfully created the USB stick. Unfortunately, I am unable to install Big Sur on my Mac Pro 5.1 with a Metal GPU. When I reboot for the first time (it does automatically during the installation process), I get the prohibition sign after a short loading process. Do you have a solution? Thanks very much!
is your 5,1 on that latest possible Mojave firmware? You should be able to boot the BigMac2 USB Installer disk from an external USB Thumb drive.
Some USB Sticks btw are too slow, recommend something like a Samsung 32GB Fit. But that is probably not your problem.
Since the introduction of race conditions at boot time with MacOS Big Sur and Monterey, it is recommended you combine BigMac2 with Open Core Legacy Patcher boot loader that has the proper .plist to boot installers and installations that have the race condition that created.
Hello and thanks for the answer. My 5.1 is already equipped with DosDudes Catalina Patcher. I used a Toshiba USB 3.0 stick for the installer. I can boot from it but when I landed in BigSur recoverymode, I cannot start the BigMac app. It is displayed but nothing happens. I wanted to install BigSur on an internal Samsung 1 TB SSD. The SSD is completely new.
Try resigning the app
If Bigmac2 app does not run, try resigning it:
codesign --force --deep --sign - /Volumes/Bigmac2/Applications/bigmac2.app
„the codesign_allocatw helper tool can not be found or used“ Thats the message in terminal booted from bigmac2 USB in recovery mode. Any suggestions? 😳 How can I combine bigmac2 and OCLP?
Run it in a full OS. Then make sure SIP is disabled.
On USB 2.0, you should be able to disable SIP from bigmac boot disk. If not do it from El Capitan boot disk or restore.
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