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authorAndre Przywara <andre.przywara@linaro.org>2013-09-19 18:06:41 +0200
committerAlbert ARIBAUD <albert.u.boot@aribaud.net>2013-10-03 21:28:25 +0200
commit16212b594f385bd594d5d316bf11b13c1186e3d7 (patch)
treec81796603104c9a9ca345ace702b01bb74d6f543 /include/configs
parent45b940d6f9a9d4989452ea67480e299bfa51ee19 (diff)
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ARM: add assembly routine to switch to non-secure state
While actually switching to non-secure state is one thing, another part of this process is to make sure that we still have full access to the interrupt controller (GIC). The GIC is fully aware of secure vs. non-secure state, some registers are banked, others may be configured to be accessible from secure state only. To be as generic as possible, we get the GIC memory mapped address based on the PERIPHBASE value in the CBAR register. Since this register is not architecturally defined, we check the MIDR before to be from an A15 or A7. For CPUs not having the CBAR or boards with wrong information herein we allow providing the base address as a configuration variable. Now that we know the GIC address, we: a) allow private interrupts to be delivered to the core (GICD_IGROUPR0 = 0xFFFFFFFF) b) enable the CPU interface (GICC_CTLR[0] = 1) c) set the priority filter to allow non-secure interrupts (GICC_PMR = 0xFF) Also we allow access to all coprocessor interfaces from non-secure state by writing the appropriate bits in the NSACR register. The generic timer base frequency register is only accessible from secure state, so we have to program it now. Actually this should be done from primary firmware before, but some boards seems to omit this, so if needed we do this here with a board specific value. The Versatile Express board does not need this, so we remove the frequency from the configuration file here. After having switched to non-secure state, we also enable the non-secure GIC CPU interface, since this register is banked. Since we need to call this routine also directly from the smp_pen later (where we don't have any stack), we can only use caller saved registers r0-r3 and r12 to not mess with the compiler. Signed-off-by: Andre Przywara <andre.przywara@linaro.org>
Diffstat (limited to 'include/configs')
-rw-r--r--include/configs/vexpress_ca15_tc2.h2
1 files changed, 0 insertions, 2 deletions
diff --git a/include/configs/vexpress_ca15_tc2.h b/include/configs/vexpress_ca15_tc2.h
index d1431e5..89ce1c7 100644
--- a/include/configs/vexpress_ca15_tc2.h
+++ b/include/configs/vexpress_ca15_tc2.h
@@ -15,6 +15,4 @@
#include "vexpress_common.h"
#define CONFIG_BOOTP_VCI_STRING "U-boot.armv7.vexpress_ca15x2_tc2"
-#define CONFIG_SYS_CLK_FREQ 24000000
-
#endif