When booting from ARM Trusted Firmware, U-Boot runs in EL1-NS.
The boot flow is as follows:
BL1 -> BL2 -> BL31 -> BL33 (i.e. U-Boot)
This boot sequence works fine for LD11 SoC (Cortex-A53), but LD20
SoC (Cortex-A72) hangs in U-Boot. The solution I found is to
read sctlr_el1 and write back the value as-is. This should be
no effect, but surprisingly fixes the problem for LD20 to boot.
I do not know why.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>