feat(debugv8p9): add support for FEAT_Debugv8p9
This patch enables FEAT_Debugv8p9 and prevents EL1/0 from
trapping to EL3 when accessing MDSELR_EL1 register by
setting the MDCR_EL3.EBWE bit.
Signed-off-by: Arvind Ram Prakash <arvind.ramprakash@arm.com>
Change-Id: I3613af1dd8cb8c0d3c33dc959f170846c0b9695a
diff --git a/lib/extensions/debug/debugv8p9.c b/lib/extensions/debug/debugv8p9.c
new file mode 100644
index 0000000..f3cffa7
--- /dev/null
+++ b/lib/extensions/debug/debugv8p9.c
@@ -0,0 +1,26 @@
+/*
+ * Copyright (c) 2024, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <arch.h>
+#include <arch_features.h>
+#include <arch_helpers.h>
+#include <lib/extensions/debug_v8p9.h>
+
+void debugv8p9_extended_bp_wp_enable(cpu_context_t *ctx)
+{
+ el3_state_t *state = get_el3state_ctx(ctx);
+ u_register_t mdcr_el3_val = read_ctx_reg(state, CTX_MDCR_EL3);
+
+ /* When FEAT_Debugv8p9 is implemented:
+ *
+ * MDCR_EL3.EBWE: Set to 0b1
+ * Enables use of additional breakpoints or watchpoints,
+ * and disables trap to EL3 on accesses to debug register.
+ */
+
+ mdcr_el3_val |= MDCR_EBWE_BIT;
+ write_ctx_reg(state, CTX_MDCR_EL3, mdcr_el3_val);
+}