Error when trying to boot from USB

[Justin]

I have a 2015 Macbook Pro11,4 and am trying to run tails from a usb. Removed the sip and successfully installed the most current version of refind, but when it tries to boot off the usb, it gives the error message "error not found while loading legacy loader." checked the firmware and its all up to date. i probably screwed up somewhere but can't figure it out. any help would be greatly appreciaed

[joshua]

Dear Justin,

I am currently having the same issue. I have a 2015 Macbook Pro 1and i installed Tails on a Usb. As my system doesn't recognize the usb with a normal reboot I also installed the most recent version of Refind. I get the same error. How did you check if the firmware was up to date? Did you already find a solution to this problem? I hope you can help me.
Thanks in advance.

Kind regards,

Joshua

[Roderick W. Smith]

Booting in BIOS/CSM/legacy mode from a USB flash drive is a hit-or-miss proposition on Macs. I did not write the relevant code in rEFInd, that code is poorly documented, and I simply don't understand much of it, so unless somebody who does understand it tackles it, that code is unlikely to improve. Even removing rEFInd from the equation and using Apple's built-in boot manager often fails, unfortunately.

The good news is that the need for BIOS/CSM/legacy-mode booting is fading fast. Chances are you can get Tails booting in EFI mode; however, doing so will require either finding help from Tails users (I'm not one of them) or decoding information from whatever Tails uses as a boot manager and re-implementing that in rEFInd's configuration. (This could mean editing refind.conf, possibly putting a secondary rEFInd on the Tails USB drive; or it could mean moving the Tails kernel and initrd file to a location that rEFInd will scan and adding a refind_linux.conf file with the required kernel parameters.)