I am running the NanoPi R6C. The device is not capable of booting from the SSD, the next best thing is to load the root filesystem from the SSD.
Using rockchip's repos, I compile from source the images to boot 1) from the microSD card and 2) from eMMC. I install to the eMMC. Then, so as not to mount any partitions from eMMC, I boot from the microSD card, and I clone the root partition from the eMMC (/dev/mmcblk2p8) to the SSD (/dev/nvme0n1p1).
I boot from the eMMC, the output of "cat /proc/cmdline" is:
storagemedia=emmc androidboot.storagemedia=emmc androidboot.mode=normal androidboot.dtbo_idx=0 androidboot.verifiedbootstate=orange earlycon=uart8250,mmio32,0xfeb50000 console=ttyFIQ0 coherent_pool=1m irqchip.gicv3_pseudo_nmi=0 rw root=/dev/mmcblk2p8 rootfstype=ext4 rootflags=discard data=/dev/mmcblk2p9 consoleblank=0 cgroup_enable=cpuset cgroup_memory=1 cgroup_enable=memory swapaccount=1 androidboot.fwver=uboot-a83a7263ef-01/09/2024
How do I change "root=/dev/mmcblk2p8" to "root=/dev/nvme0n1p1"?
I connect to the serial port and get to the U-Boot monitor. I examine the variables. "bootcmd" runs "bootrkp" which boots the system. "bootrkp" ignores "bootargs", I confirm this by deleting "bootargs" before running "bootrkp", the system boots up as before with no change in behavior. "bootrkp" is implemented in file "cmd/bootrkp.c". That code emits the equivalent of:
setenv bootm-no-reloc y booti 0x400000 0xa200000:0x7b2bc0 0x8300000
Can I tell U-Boot to load the root partition from /dev/nvme0n1p1, either by entering commands at the monitor, or by modifying the source code of U-Boot, or through any other means?
Regards, Eric