You’re in luck! However, you will need to use serial console. See:
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...
Retrieving file: /boot/extlinux/extlinux.conf
213 bytes read in 114 ms (1000 Bytes/s)
p2771-0000 eMMC boot options
1: primary kernel
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).