ThinkPad

TL;DR you can install Libreboot on a T470 with a 7th-gen Intel processor as you would any T480.

Everything below is relevant to T470 units with a 7th-gen Intel CPU. I don't have a 6th-gen Intel unit to test and those may have a different chipset.

The T470 and T480 have very similar hardware, with Intel 7th-gen CPU options available for both models. So out of curiosity, I decided to try flashing the T480 build of Libreboot 25.06 to my T470.

If you are new to Libreboot or Coreboot, I'd suggest going through the documentation first, i.e. https://libreboot.org/docs/install/t480.html. A good video guide is also available: https://www.youtube.com/watch?v=iGKhsjvlSBQ. As for BIOS and Thunderbolt firmware, I just updated to the latest versions of each for the T470.

An external BIOS chip programmer is necessary for installing Libreboot itself. I chose to use the CH341a. If you choose to do so as well, be aware that

• without an adapter, the CH341a will push 3.3 volts to the BIOS chip, even though the actual chip in the T470 is rated for 1.8 V
• the chip did survive many previous me_cleaner tests and the final Libreboot flashing despite using an unmodified CH341a. YMMV, use at your own risk.
• Pins 1,2,3,4 are along the same side of the socket as the lever. Use the 25xx section.
• it is always a good idea to back up and double-check the original BIOS chip contents before flashing Libreboot

Libreboot starts up normally and Linux boots with no issue. While I have not exhaustively tested every feature of the T470, I can go about my daily tasks as usual and write this post on my Librebooted T470. Caveats found on the T480 seem to apply to the T470 as well, most notably with the audio jack and internal microphone. Neither of these components are working, although the documentation suggests USB sound cards as a workaround for now. Internal speakers and webcam do work, however.

EDIT: USB-C charging works, but data transfer does not. I'm not terribly surprised though since that section of the board did go from having a dedicated charging port and single USB-C connector on the T470 to having two USB-C connectors and a mini dock connector on the T480.

Additionally,

• No noticeable difference in performance or battery life (I had previously disabled hyperthreading, but Libreboot prebuilt images have it disabled as well).
• TrackPoint felt somewhat harder to use, but that was alleviated by switching from libinput to evdev (note evdev is not supported in Wayland sessions).
• Expected in hindsight since I just used the T480 build as-is, but the laptop will now identify itself as a T480 in various hardware info utilities.
• Intel ME has been neutered.

If you are looking to buy a laptop for Libreboot, I would suggest you skip the T470 since it is only dual core and instead go for the T480 since it comes with a much more performant quad core if the CPU is 8th-gen. But for those of us who already have a T470 or for any reason are limited to buying a T470, Libreboot is an option for us too!