chore: fvp_r: Initial No-EL3 and MPU Implementation
For v8-R64, especially R82, creating code to run BL1 at EL2, using MPU.
Signed-off-by: Gary Morrison <gary.morrison@arm.com>
Change-Id: I439ac3915b982ad1e61d24365bdd1584b3070425
diff --git a/plat/arm/board/fvp_r/fvp_r_misc_helpers.S b/plat/arm/board/fvp_r/fvp_r_misc_helpers.S
new file mode 100644
index 0000000..67ad164
--- /dev/null
+++ b/plat/arm/board/fvp_r/fvp_r_misc_helpers.S
@@ -0,0 +1,32 @@
+/*
+ * Copyright (c) 2021, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <asm_macros.S>
+
+ .globl disable_mpu_el2
+ .globl disable_mpu_icache_el2
+
+/* ---------------------------------------------------------------------------
+ * Disable the MPU at EL2.
+ * ---------------------------------------------------------------------------
+ */
+
+func disable_mpu_el2
+ mov x1, #(SCTLR_M_BIT | SCTLR_C_BIT)
+do_disable_mpu_el2:
+ mrs x0, sctlr_el2
+ bic x0, x0, x1
+ msr sctlr_el2, x0
+ isb /* ensure MMU is off */
+ dsb sy
+ ret
+endfunc disable_mpu_el2
+
+
+func disable_mpu_icache_el2
+ mov x1, #(SCTLR_M_BIT | SCTLR_C_BIT | SCTLR_I_BIT)
+ b do_disable_mpu_el2
+endfunc disable_mpu_icache_el2