Topic: U-Boot and SATA woes
Right now (to my understanding), U-Boot's SPL at the start of the SD card loads the u-boot.img on the /boot partition of the SD card which chooses a kernel to load from /boot and boots that with the rootfs on the SD card or SATA disk depending on the eeprom.
This means the SATA drive can't run its own boot arguments, its own kernel or it's own U-Boot. When porting a distro on that doesn't use systemd as it's loader and messing with kernels that needed a newer U-Boot, this was problematic. It seems right now the best way to do this is to hack things in to a uEnv.txt file.
It'd be nice to be able to run the SPL on SATA, or have the main SPL load U-Boot off of the SATA (though I'm not sure if it'd be stable.) I'm not sure if that's actually going to happen.
As a compromise,. would it be a good idea to allow sourcing a custom U-Boot script from the SATA drive when not using recovery mode? If this is a good idea, I could try writing a patch.