Booting OS from SD card: consistency issue

[pivic]

update uboot or replace the sdcard.

Thanks! I've read up a bit on uboot; it seems far too complicated to update for a Linux noob like myself, so I'll start off by trying a new SD card. The one I've used is from Pine64 but I guess it could be that the card itself is wonky.

Updating uboot could be as simple as reflashing your eMMC with a different/newer OS image.

Oh. I've used two different OSs with the same SD card already, with the same result, i.e. it's still a 30/70 chance that boot leads to SD image/HDD OS. Or do you mean that I could reflash the OS on the computer?