MP 1,1-5,1 MacPro5,1 (Mid 2012) boot Opt workaround for USB macOS installer?

[claudiop]

Hi, newbie here

I've created a macOS Catalina on USB Flash drive using 'Install macOS Catalina.app' (specific to my device) and the 'createinstallmedia' command. It goes through the process including making disk bootable and mounting it.

In order to run the USB installer, I restart but my MacPro (Mid 2012) doesn't allow holding the Option key in order to select the Installer.

I've tried SystPrefs>Startup but it doesn't 'see' the USB installer.

Apologies for dumb question, is there a workaround?

cheers

 

[tsialex]

If you don't have a GPU that have pre-boot configuration support, you will always boot with the priority order from the firmware (SATA, PCIe, Firewire, USB). USB always has the lowest priority.

So, to boot a createinstallmedia USB key without the BootPicker, just remove any other bootable disk (nuke/wipe the disk you want to install macOS first). Mac Pro firmware will then scan each disk installed on your Mac Pro, with the firmware order above, and then boot the only one bootable found, the createinstallmedia USB key.

Btw, it's not very wise to try to install a hacked install without knowing the limitations/workarounds. Install a supported macOS release before anything (HighSierra or Mojave).

 

[claudiop]

Thanks for clarifying that tsialex....much appreciated

I've successfully installed a macOS Mojave with OpenCore (cdf guide). My next steps will be Catalina then Big Sur. I've got all the macOS installers specific to my Mac Pro.

thanks