Fedora 25 not booting after update

[Matt Morgan]

The last time I signed off of Fedora 25, I opted to install updates.

Now it boots to a minimal grub menu, with no listing of kernel choices. I'm
sorry to say I haven't understood grub well for about 10 years. But I
looked up some guides to using the menu (without success).

If I type 'exit,' I am able to boot Windows, which is dual installed. But I
guess Grub can't find a kernel to boot, and I suppose it can't find its own
config?

I tried things like

boot (which said I needed to tell it a kernel to use first)
linux (which I thought was a way to load a kernel, but I just get "error:
command 'linux' not found")
ls (which can see the partitions, but can't tell what fs they are using,
for the most part).

Seems like the ls is kind of the issue--with the exception of one ext2
partition (swap I guess) and one FAT (Windows), grub can't read the
filesystems on the disk, so I can't tell it what kernel to boot.

Can anyone provide any guidance?

FYI, this is an HP Envy laptop, if that helps.

Thanks,
Matt