I want to install an additional root file system on the SD card and use the debug port to choose from either eMMC or the SD card. How to prepare the SD card to achieve this? And what changes should I do to the u-boot to achieve this? Basically, I want to have a dual boot.
Things I tried
I split the SD card into two partitions. I copied the rootfs to the first partition (ext4) and executed
./apply_binaries.sh -r /media/SDcard/rootfs
Below is the dump of the u-boot printouts on the debug port.
U-Boot 2016.07 (Feb 28 2020 - 11:42:29 +1100) TEGRA186 Model: NVIDIA P2771-0000-500 DRAM: 7.8 GiB MMC: Tegra SD/MMC: 0, Tegra SD/MMC: 1 *** Warning - bad CRC, using default environment In: serial Out: serial Err: serial Net: eth0: ethernet@2490000 Hit any key to stop autoboot: 0 switch to partitions #0, OK mmc1 is current device Scanning mmc 1:1... switch to partitions #0, OK mmc0(part 0) is current device Scanning mmc 0:1... Found /boot/extlinux/extlinux.conf Retrieving file: /boot/extlinux/extlinux.conf 733 bytes read in 68 ms (9.8 KiB/s) L4T boot options 1: primary kernel Enter choice:
I am also a bit confused about the role the extlinux.conf file in the booting of the kernel. It just helps us choose between kernel images on the same partition, right?