Installation issue on Lenovo Ideapad 120S

[Vincent DEFERT <vincent.defert%posteo.net@localhost>]

Hi!

I'm trying to install NetBSD 10.1 on a Lenovo Ideapad 120S-14IAP 
(Pentium N4200, 4GB RAM, 2017, i915) from a USB stick.
UEFI boots it properly and I see NetBSD's logs scroll until the display 
switches to graphics mode.
At this point, the screen is covered with strands of green pixels, 
completely unusable.

Is there a way to force the installer to stay in text mode to avoid this?

Vincent