Whichever uboot you have on emmc..... (bootrom search order,,,SPI, emmc, uSD)
strings uboot |grep -i boot_target ,,,, (usually "boot_targets=mmc1 nvme0 usb0 mmc0 pxe dhcp",,, mmc1 is uSD)
each of these is searched (in order) for boot.scr OR extlinux.conf OR bootaa64.efi
Inside one of these, the 1st one found, will be a root= statement
For boot.scr it sometimes hard to find what root is, often a uEnv.txt for over rides
BTW
>But I checked the source device ID for the root partition, and dd'ed to the other device.
Nearly always, the emmc will have boot0 and boot1 sections on it,,, don't use them
ie /dev/mmcblk1boot0 for example,, mmcblk1 is emmc,, write to /dev/mmcblk1
I do have a recent 128GB emmc that does NOT have boot0 and boot1 sections
strings uboot |grep -i boot_target ,,,, (usually "boot_targets=mmc1 nvme0 usb0 mmc0 pxe dhcp",,, mmc1 is uSD)
each of these is searched (in order) for boot.scr OR extlinux.conf OR bootaa64.efi
Inside one of these, the 1st one found, will be a root= statement
For boot.scr it sometimes hard to find what root is, often a uEnv.txt for over rides
BTW
>But I checked the source device ID for the root partition, and dd'ed to the other device.
Nearly always, the emmc will have boot0 and boot1 sections on it,,, don't use them
ie /dev/mmcblk1boot0 for example,, mmcblk1 is emmc,, write to /dev/mmcblk1
I do have a recent 128GB emmc that does NOT have boot0 and boot1 sections