I had my Mac Pro 1,1 running 10.10 and on the system attempted an update install to (I believe 10.10.2). When it rebooted I got the blinking ? folder.
So to diagnose I booted back into 10.7.5 and discovered the boot.efi had been created and modified in the update in both /System/Library/CoreServices/ and in /usr/standalone/i386/.
I tired copying over Tiamo's boot.efi again (and repairing permissions etc.) but receive what looks like a kernel panic on boot.
Any Thoughts would be appreciated. I really need the system back.