Wrong LCD resolution on RPI

[Lloyd Parkes <lloyd%must-have-coffee.gen.nz@localhost>]

Hi all,
I have what I think is a standard Raspberry PI 7" LCD on my RPI 3 B. 
It's resolution is listed as 800 x 480. I'm running the latest disk 
image from Jun (2022-10-16).

When I boot NetBSD on it, the console is described by stty as 80x22 and 
while the text columns reach to both sides of the LCD shroud, the rows 
seem to to stop one row short of both the top and bottom of the shroud. 
I double checked the rainbow boot logo and it reaches all the way to the 
top and bottom of the LCD shroud.

dmesg tells be that the genfb is 1280 x 720 and X also only wants to run 
in 1280 x 720, but X is obviously scaled down to try and work with the 
actual LCD resolution. X displays all the way to the LCD shroud sides, 
but like wscons it doesn't display all the way to the top and bottom of 
the shroud.

Does anyone know how to adjust genfb's resolution? I've had a look at a 
few things in documentation for config.txt and it all seems to be 
related to HDMI and third party displays, neither of which I have.

Cheers,
Lloyd