>and from what I understand (perhaps incorrectly), u-boot on microSD can override u-boot on eMMC if u-boot on eMMC is configured to redirect the SoC to boot from microSD first.
No, 1st uboot found (really idbloader) will be the one used
This is why "boot_targets" in uboot,,,,, nearly always a SD boot is using the emmc uboot
So you really have no idea if the uboot on SD is going to be OK if it is written to emmc
Since nothing is mounted (in a file system tree) by uboot, it has to take into account both 1 & 2 partition systems
So, 6 things to look for (3 * 2,,, ie, /boot.scr,,,,,/boot/boot.scr)
Oh,, I know not so many people are still using bios firmware,, so I write bios/firmware
The difference is that bios established a standard for most hardware, not the case in the arm world
No, 1st uboot found (really idbloader) will be the one used
This is why "boot_targets" in uboot,,,,, nearly always a SD boot is using the emmc uboot
So you really have no idea if the uboot on SD is going to be OK if it is written to emmc
Since nothing is mounted (in a file system tree) by uboot, it has to take into account both 1 & 2 partition systems
So, 6 things to look for (3 * 2,,, ie, /boot.scr,,,,,/boot/boot.scr)
Oh,, I know not so many people are still using bios firmware,, so I write bios/firmware
The difference is that bios established a standard for most hardware, not the case in the arm world