no video modes listed by grub

[alexflint]

I am trying to boot a simple unikernel on a 2016 Dell XPS. I am booting via grub 2.06. I was getting the "requested video not supported" error so I wrote a grub menuentry to list all the available video modes:

Code: Select all

menuentry "videoinfo" {
	videoinfo
        sleep 10
}

However, no video modes are listed at all!

I am booting from a USB key created using grub-mkrescue. I did not specify a --platform so it's using /usr/lib/grub/i386-pc/boot_hybrid.img

Any idea why no video modes are listed and/or what I might try to debug further?