After finalising some details of this feature, I am sharing the sources and the binary:
https://github.com/spark2k06/Main_MiSTe ... c97088de20
It also includes support for the TapTo service, more info here:
viewtopic.php?p=83273#p83273
https://github.com/spark2k06/Main_MiSTe ... ng-screen/ (all commits)
As for the loader screen, it is configured and activated as follows:
If there is a loader_bg.png or loader_bg.jpg file in the root directory, it will be used as background of the original loader, i.e. the original loading information and progress will be overdrawn over the image.
If there is a loader.png or loader.jpg file in the root directory, it will be used as a foreground of the original loader, i.e. the image will replace the original loader for all purposes, hiding it.
If neither of these two files is present, the original loader with the loading status information will be used.
Finally, it should be noted that the loader as background has priority over the loader as foreground, i.e. if both files are present, the loader as background will be used.
I'm not even going to try to make a PR of these features to sorgelig because it will be rejected for sure, I want them for personal use in my living room setup, if someone finds it useful or it looks like it can fit in other Main repositories that are maintained and updated like funkycochise's InsertCoin, feel free to integrate it.
On the other hand, as soon as I get support from the TapTo service that runs wizzomafizzo to detect all compatible NFC readers through its API, I will also update this repository to use it and the detection icon will support all of them, not just the ACR122U reader