Moving my ‘mid 2011’ Mac mini to macOS High Sierra was not easy and it seemed it was stuck there. Apple said that macOS Mojave was not available for my machine and the same was true for macOS Catalina, launched in October 2019 and now at version 10.15.5.
Then I discovered Dosdude1’s Catalina Patcher, currently in version 1.4.4. My model’s identifier was ‘Macmini5,1’, and its graphics were ‘Intel HD Graphics 3000 384 MB’, a combination that the patcher said it would support. In getting High Sierra to work, I had already bumped the Mac’s memory up to 4 GB, the minimum required for Catalina.
Catalina Patcher
The patcher software had a video tutorial, which was very clear. The tutorial recommended using a bootable drive to install Catalina but I decided to risk installation in place.
Installation in place did not work first time. After the Catalina installer had been downloaded, a message explained that SIP (System Integrity Protection) was enabled and would need to be disabled. This involved rebooting the Mac into Recovery Mode (Command + R, at the chimes), opening Terminal under Utilities in the menu, using the command csrutil disable, and rebooting.
Once SIP was disabled, with one exception, the process was as explained in the tutorial, using the copy of Install macOS Catalina that was now in Downloads.
The exception was that, at the end, the process stuck on a grey screen with the Apple logo and a stationary progress bar that was between 80% and 90% of the way through. After waiting long enough that I was confident that something was stuck rather than very slow, I turned off the Mac by its power button. Research suggested that peripherals could affect booting and the Mac had a USB drive plugged in. I removed it, turned on the Mac, and it booted (slowly) into Catalina.
No Metal compatibility
Metal is an Apple graphics API. On macOS, it supports Intel HD Graphics from the 4000 series. The video tutorial warned about applications expecting Metal compatibility, specifically Apple’s Maps application. However, that warning is missing from the current version of the patcher and Maps seems to work as expected.
The video tutorial had also warned of minor problems with Catalina’s light theme, but this had been fixed in version 1.2.3 of the patcher.
No Recovery Mode?
I wondered if SIP should be re-enabled, which would require booting into Recovery Mode. I discovered that the Mac could no longer be booted into a Recovery Mode.
Following a guide on Reddit r/CatalinaPatcher, I used the patcher software again to create a bootable drive from a 32 GB USB key drive (reformatted as macOS Extended Journaled with scheme GUID Partition Map). Booting from that drive provides a Recovery Mode.
Microsoft Office
Microsoft Office applications would not launch successfully, the error report referring to ‘code signing’.
Version 1.3.6 of the patcher (from 31 March 2020) said that it fixed an issue where AMFI (Apple Mobile File Integrity) could prevent some third-party applications from launching in macOS 10.15.4.
Announcing that patch, Dosdude1 also suggested run sudo nvram boot-args=amfi_get_out_of_my_way=0x1 in Terminal. Doing so seemed to fix the problem.
The nvram command allows firmware variables to be set in NVRAM (non-volatile RAM). Variable boot-args holds arguments used when booting the XNU kernel – the part of the operating system that loads first. According to a presentation by Jonathan Levin, Setting boot argument amfi_get_out_of_my_way disables AMFI altogether.
Upgrading Xcode
Version 11.5 of Apple’s Xcode application weighs in at about 8.1 GB. A couple of attempts to update to that version fell over at the end of a slow process. Finally, the upgrade was offered up by App Store and, after a long installation process, installed successfully.