As of U-Boot v2017.01, booting Linux kernels via GRUB is known to be working on the following SoCs (boards):
•Allwinner A64 (Pine64)
•Altera Cyclone V (DE0-Nano-SoC)
•Amlogic S905 (Odroid-C2)
•Broadcom BCM2835/2836/2837 (Raspberry Pi 1/2/3)
•HiSilicon Kirin 620 (HiKey)
•Marvell Armada 388 (ClearFog)
•Nvidia Tegra K1 (Jetson TK1)
•NXP i.MX 6SoloX (Udoo Neo)
•NXP QorIQ LS2085A (LS2085ARDB)
•Rockchip RK3288 (Firefly-RK3288)
•Texas Instruments Sitara AM3358 (Beagle Bone)
•Xilinx Zynq UltraScale+ MPSoC (ZCU102)