darkstar Chainloading mainline u-boot is not a "solution" it is a "workaround" and the root cause of the problem is still not known. AFAIK the .ext file should not need to be recompiled for SD card boot because it is the unsigned u-boot.bin binary with no embedded device-tree, and thus to run it you've already booted (via vendor u-boot) past the point where SD/eMMC selection is in play. As there is no device-tree embedded the file should be usable on more than one device, but is probably SoC generation specific, e.g. GXBB, GXL/GXM, G12A/SM1, G12B might need different files. I'm personally not too interested in using this approach although the current LE "box" image will see/use the file if present. NB: I've also upstreamed support for GT-King/Pro allowing people to run mainline u-boot from eMMC on these devices, particularly for Armbian where people are more keen/willing/able to do that. Those patches will be in-tree once the merge window for U-Boot 2021.04 opens, and they are included in my 2021.01 fork. I'm still hopeful that one of the kernel maintainers we shipped hardware too will be able to pinpoint the real problem and solution.
Thank you for your reply, we can use it as a workaround till we get a real solution that you mentioned.
Show the link to the original source, I want to look at the "author".
I don't know the sources link. I guessed that it is compiled by chewit or you and just wanted to ask.