ARM: add C function to switch to non-secure state
The core specific part of the work is done in the assembly routine
in nonsec_virt.S, introduced with the previous patch, but for the full
glory we need to setup the GIC distributor interface once for the
whole system, which is done in C here.
The routine is placed in arch/arm/cpu/armv7 to allow easy access from
other ARMv7 boards.
We check the availability of the security extensions first.
Since we need a safe way to access the GIC, we use the PERIPHBASE
registers on Cortex-A15 and A7 CPUs and do some sanity checks.
Boards not implementing the CBAR can override this value via a
configuration file variable.
Then we actually do the GIC enablement:
a) enable the GIC distributor, both for non-secure and secure state
(GICD_CTLR[1:0] = 11b)
b) allow all interrupts to be handled from non-secure state
(GICD_IGROUPRn = 0xFFFFFFFF)
The core specific GIC setup is then done in the assembly routine.
Signed-off-by: Andre Przywara <andre.przywara@linaro.org>
diff --git a/arch/arm/cpu/armv7/Makefile b/arch/arm/cpu/armv7/Makefile
index 3466c7a..024c28b 100644
--- a/arch/arm/cpu/armv7/Makefile
+++ b/arch/arm/cpu/armv7/Makefile
@@ -22,6 +22,7 @@
ifneq ($(CONFIG_ARMV7_NONSEC),)
SOBJS += nonsec_virt.o
+COBJS += virt-v7.o
endif
SRCS := $(START:.o=.S) $(COBJS:.o=.c)