[U-Boot] U-Boot as first bootloader on Exynos platforms

Hi,

I was told some time ago that a publicly-available version of the Samsung Chromebook 2 (supposedly, the one with an Exynos 5800 SoC) allows running unsigned code (the U-Boot SPL) directly after the bootrom. Is that correct?

Do you know of any (other) publicly available device with an Exynos SoC that doesn't check for the first bootloader's signature, and thus could load the U- Boot SPL without any intermediary signed stage on storage memory?

Cheers,