Secure bootloading for Android ... are there any?

[Android Question]

Is there a bootloader setup for Android that provides "secure-boot" functionality akin to UEFI?

Offering digital signature verification of kernel and system image on boot?

 

[jhawkkw]

Many device come with locked bootloaders that do just that. They check the signature on the kernel, system, and recovery and if something doesn't match up, it either refuses to boot, or displays an error and holds there until the partition at fault is reset to something accepted.
Oddly enough, one of the common struggles of the online android community to find ways around this secure booting feature so that they can customize their device the way that they want.