[Librem-5-dev] U-Boot support for uSD

[Andy Green]

Hi -

It seems my reasonably midrange for 2018 uSD (Sandisk Ultra U1 32GB) 
cannot be brought up by U-Boot on the dev board.

  u-boot=> mmc dev 1
  Card did not respond to voltage select!
  mmc_init: -95, time 29

But there's no evident problem using that card on a Linux box via a 
cheapo USB adapter.

"Just me"?  Known issue not on the list of known issues[1]?  Any 
recommended cards that do work?

(Please don't send me to some non-scalable "chat"... let's get the 
answer on the ml and in google... maybe even in the docs...)

Thanks...

-Andy

[1] 
https://developer.puri.sm/Librem5/Development_Environment/Boards/Known_Issues.html