Add Goodix fingerprint device firmware update

[mpi3d]

Hello, I'm currently developing drivers for Goodix fingerprint chips with a community.

The chips use the TLS protocol to communicate. So we need to write a PSK key.
But to do that we need to erase the chip firmware, then it reboots in a special mode.
In this mode, we need to write the PSK and the firmware.
After that, we are able to communicate with the device.

We can't read the PSK from the device, so we need to write it each time that the computer booted another OS (Windows). This is very problematic for dual boot.

We have already successfully flashed the chip firmware. And we have already retrieved an image from the sensor.

So we began writing the driver.
But libfprint developers don't want to include a firmware flashing in the driver.

So we separated both:

• Driver: rootd/libfprint
• Firmware flashing: mpi3d/goodix-fp-dump

But many people in the community asked to add the firmware flashing in fwupd. So that why I'm opening this issue.

Our last problem is that firmware binaries are the Goodix property, so it's not legal to distribute them.
Since I'm not a lawyer, I don't know how to distribute them in a legal way.
But I hope you have some ideas of how to distribute that legally.

The goodix TLS community

[superm1]

We can't read the PSK from the device, so we need to write it each time that the computer booted another OS (Windows). This is very problematic for dual boot.

This makes sense. I think I would treat the dual boot problem and the firmware flashing problem as two tangential but related issues. So really this breaks down into 3 questions:

1. The dual boot problem is really an availability of the PSK issue.
2. Firmware flashing (fwupd support)
3. Firmware distribution

I suggest get the firmware flashing sorted first, the distribution next (or in parallel) and then we can figure out some ways that the PSK can be shared between multiple OSes.

But many people in the community asked to add the firmware flashing in fwupd. So that why I'm opening this issue.

Makes sense. So we have a plugin writing tutorial available here:
https://fwupd.github.io/libfwupdplugin/tutorial.html

We have a contributing guide here:
https://github.com/fwupd/fwupd/blob/master/CONTRIBUTING.md

You can use those to port your standalone flashing support into fwupd.
You can give it a try and open a draft pull request and if you have questions along the way you can leave some comments in the PR and we can try to help you with them.

We can't read the PSK from the device, so we need to write it each time that the computer booted another OS (Windows). This is very problematic for dual boot.

How is this PSK used and created? When initially shipped it's empty, and then the OS driver creates it the first time that it communicates with the device? If so, would you consider modifying the driver to write it somewhere easily accessible to multiple operating systems but that needs permissions to access like the EFI NVRAM or the TPM?

Our last problem is that firmware binaries are the Goodix property, so it's not legal to distribute them.
Since I'm not a lawyer, I don't know how to distribute them in a legal way.
But I hope you have some ideas of how to distribute that legally.

Firmware binaries used by fwupd is most commonly distributed by the Linux Vendor Firmware Service. You don't need to distribute the source for the binaries, just the binaries and metadata associated with them to describe the firmware such as device it's for, version, any changelog you want to share. When you distribute them via LVFS all end users running Linux distributions with fwupd and your device will be able to download the updates.

You can see here a list of all the vendors that use this service: https://fwupd.org/lvfs/vendors/

FYI, it may take a few weeks to get an account made as the person who normally does this is on PTO.

[superm1]

Okay so it's proprietary firmware, you will not be able to redistribute it to LVFS.

[mpi3d]

Ok

[mpi3d]

@superm1 Btw, it seems that fwupd already support goodix-moc (it would be goodix-tls for our firmwares). But where are the goodix-moc firmwares?

[hughsie]

But where are the goodix-moc firmwares?

It's currently uploaded but embargoed. I think the Goodix team might be open to the idea of uploading more.

[mpi3d]

Ok. So I think the best idea is to write the driver for fwupd then ask Goodix to publish the firmware binaries.