How to update coreboot offline

[radiant]

i am currently having problems with pureboot + librem key and it has been suggested that i reflash pureboot.

Librem key problems: reset key + signing files in /boot

There is a lot missing from the documentation, but we are going to ignore discussing it for now and simply deal with your issue first. Follow these instructions to reflash PureBoot. The order of operation I suggest is to flash Coreboot first, then flash PureBoot over it in a separate sequential session. After rebooting, you will be prompted to do a factory reset in PureBoot. Accept it and you will be able to properly use the Librem Key for boot firmware tamper protection purposes.

given this most recent post, i expect nothing has moved on this front, which is disappointing.

i recently updated the embedded controller on a librem 14 and updating that does indeed have its own image and process that does not require pureos or going online.