The full SPL support is not quite ready for Allwinner A64 yet, but these fixes are likely to be necessary. Of course, unless the problem is actually caused by wrong voltages and the AXP803 PMIC support magically fixes it.
PS. Discovered when developing a sunxi-fel based SPI flash programmer tool and trying to use the SRAM C on A64 as a temporary buffer (after loading the U-Boot SPL with the hope to gain more speed from the higher CPU and AHB clock speeds).
Siarhei Siamashka (2): sunxi: Downclock AHB1 to 100MHz on Allwinner A64 sunxi: Move the SPL stack top to 0x1A000 on Allwinner A64/A80
arch/arm/include/asm/arch-sunxi/clock_sun6i.h | 5 +++++ include/configs/sunxi-common.h | 5 ++--- 2 files changed, 7 insertions(+), 3 deletions(-)