Hi - I copied a new Image file into /boot but first I copied the original file to Image.backup and edited /boot/extlinux/extlinux.conf .
I reboot and the system doesn’t start up with my new image. I’d like to get it back to the old setup.
How do I reboot using Image.backup ?? Is this possible ?
Thanks,
Jamie
You’re in luck! However, you will need to use serial console. See:
https://www.jetsonhacks.com/2019/04/19/jetson-nano-serial-console/
Serial console works even in stages prior to the Linux kernel loading. There is a very brief moment prior to Linux loading that it asks you to pick a kernel (any key interrupts boot here, but it is easy to miss if you don’t know what you are looking for). If you hit a key a bit too early you drop into the U-Boot command line, and must run command “boot” to continue boot. A very short time after that point you will see something similar to this, which is when you actually want to interrupt boot with a keystroke:
Scanning mmc 0:1...
Found /boot/extlinux/extlinux.conf
Retrieving file: /boot/extlinux/extlinux.conf
213 bytes read in 114 ms (1000 Bytes/s)
p2771-0000 eMMC boot options
1: primary kernel
Enter choice:
You can hit the backspace key to get rid of the character you interrupted boot with, and then, depending on your kernel list, you’ll enter either “1” or “2” to pick the kernel (the above only has “1” because it has only one kernel entry, but yours would have “2” as well).
Super helpful! Thanks for the clear instructions. I have an FTDI cable and was able to connect it to the UART. Used CoolTerm to read the messages and then entered a 2 just in time :). Thanks again