I wanted to leave a note about running the restore tool(s) on the current MacOS Catalina that the wiki doesn’t cover. With the new application gatekeeper, when you try to run
./bootfix.osx you’ll get a warning message about being unverified and it won’t execute.
To make it work, you can go into
System Preferences -> Security & Privacy -> General. Under the “allow apps” section, you should see a notice about bootfix.osx and an option to “Allow anyway”. Click that, and then you should be able to run
./bootfix.osx from the command line.