GitLab

If an SoC has the "secure boot" fuse burned, it will enter FEL mode in
non-secure state, so with the SCR.NS bit set. Since in this mode the
secure/non-secure state restrictions are actually observed, we suffer
from several restrictions:
- No access to the SID information (both via memory mapped and "register").
- No access to secure SRAM (SRAM A2 on H3/A64/H5).
- No access to the secure side of the GIC, so it can't be configured to
  be accessible from non-secure world.
- No RMR trigger on ARMv8 cores to bring the core into AArch64.
Those limitations make a board pretty useless for many applications.

However it has been found out that a simple "smc" call will immediately
return from monitor mode, but with the NS bit cleared, so access to all
secure peripherals is suddenly possible.

Add all the necessary support code for doing a runtime check and
activating this workaround. Affected SoCs need to have the "smc"
workaround enabled in their soc_info struct.
Signed-off-by: Andre Przywara <osp@andrep.de>
["sunxi-fel smc" command changed to automatic detection by Siarhei]
Signed-off-by: Siarhei Siamashka <siarhei.siamashka@gmail.com>