Installation boot problems on Lenovo T420

[cedar...@resist.ca]

Hi everyone (Sorry if this is a double post, my post from a few hours ago
didn't seem to go through)

Would-be new user of Qubes here, but a longtime Linux user. I'm trying to
install Qubes-R3.1-x86_64 on a Lenovo Thinkpad T420. I encountered the
"hangs on penguins" problem described here:

https://www.qubes-os.org/doc/uefi-troubleshooting/

I followed the steps there and they all worked well, until the very last
section where it asks for " /boot/efi partition number". I don't know what
that is and I don't think it came from the previous steps. I tried it with
the entry number and with a similar number that came up during a different
step, but neither worked.

One time it gave me an error reading "segmentation fault" and something
about needing a unique instance. When I rebooted, I couldn't boot to
anything. Another time it created two instances of Qubes in the boot menu
but trying to boot to either got stuck at penguins.

I think all I really need is to know what a partition number is and where
to find it. Googling hasn't helped me so far, and I'd really appreciate
any help you all could provide.

Thanks so much for all your work!! Looking forward to getting Qubes going.

-CR

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