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-rw-r--r--lib/extensions/brbe/brbe.c27
1 files changed, 27 insertions, 0 deletions
diff --git a/lib/extensions/brbe/brbe.c b/lib/extensions/brbe/brbe.c
new file mode 100644
index 0000000..1982619
--- /dev/null
+++ b/lib/extensions/brbe/brbe.c
@@ -0,0 +1,27 @@
+/*
+ * Copyright (c) 2022, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <arch.h>
+#include <arch_features.h>
+#include <arch_helpers.h>
+
+void brbe_enable(void)
+{
+ uint64_t val;
+
+ if (is_feat_brbe_present()) {
+ /*
+ * MDCR_EL3.SBRBE = 0b01
+ *
+ * Allows BRBE usage in non-secure world and prohibited in
+ * secure world.
+ */
+ val = read_mdcr_el3();
+ val &= ~(MDCR_SBRBE_MASK << MDCR_SBRBE_SHIFT);
+ val |= (0x1UL << MDCR_SBRBE_SHIFT);
+ write_mdcr_el3(val);
+ }
+}