11-15-2022, 10:43 AM
You pretty much need to have U-boot on the eMMC. The hardware looks there before scanning the micro-SD. If you don't have a valid U-boot on the eMMC, you can't boot from SD. Now, valid includes being all zeroes. But in my opinion, it's just as easy to corrupt all zeroes as it is to corrupt good code. Especially if you or something forgets to leave that space alone.
SPI-ROM is scanned before the eMMC. So if you want to foolproof your PBP so that you don't have to open it, you really want U-boot, or more likely, Tow-boot on the SPI ROM. Do this at your own risk. I don't recommend doing it either. If you make a mistake there, it's much harder to recover than if U-boot gets corrupted on your eMMC.
SPI-ROM is scanned before the eMMC. So if you want to foolproof your PBP so that you don't have to open it, you really want U-boot, or more likely, Tow-boot on the SPI ROM. Do this at your own risk. I don't recommend doing it either. If you make a mistake there, it's much harder to recover than if U-boot gets corrupted on your eMMC.
:wq
