[split] U-Boot with NVMe support, keyboard & display working

[belfastraven]

@freerk I'll preface that I have not done any testing that includes any patches or build systems outside of my Nix derivations in the repository. I do not have the hardware to setup NVMe drives, thus I can't test, thus I don't provide such builds.

Now, from the linked repository, in the FAQ:

My machine does not boot after installing to SPI and is not in maskrom mode

Oof, first of all, sorry. In testing I have never had a flashing render my device unbootable.

Rescuing your device is not specific to this project. You can follow the instructions from the Pine64 forums to recover from a broken SPI flash.

Your machine is unlikely to be fully bricked, but might require some love and care to bypass the SPI boot. Follow the link. I haven't personally had to use this method, but it is rooted in well-known knowledge about the RK3399 boot flow, so it looks totally sane.

You can use the firmware installer image, if you have used that to install, to zero out the SPI. Alternatively you can fish out the proper sf command to do the equivalent.

Any builds other than those produced by my unmodified Nix derivation stand squarely in YMMV territory as far as I'm personally concerned.

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@as400  I noticed that two days ago additional doc was posted here:  https://github.com/samueldr/wip-pinebook...830e725b4b,  in which he states  in the issues section that kernels above 5.5 are not booting, and mentions a couple of other issues (problematic input, possible interference between screen and serial output)

This particular document was present in the PR from day one. I also made sure to say (on IRC) that there was some caveats and to fully read the added docs to understand possible issues.

Though, some community members (@as400) have had better success with booting a 5.5+ kernel with that U-Boot, while I haven't been able to reproduce consistent or even 75%-successful boot rates.

Now, those caveats are a good chunk of the reason this wasn't simply made the new gold standard . Hopefully soon we'll have had people that deeply know more about the subjects look into the issues and figure out what is actually happening.

@samueldr, Just to clarify,  I wasn't complaining--I have been able to occasionally boot a 5.7 Manjaro kernel, (probably 25% of the time)  and I really appreciate what you have done.  I just wasn't sure that as400 had seen the comment.