thermosphere: add some basic sysreg trapping code

thermosphere/src/traps.c

@@ -1,5 +1,35 @@
+/*
+ * Copyright (c) 2019 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
 #include "traps.h"
 #include "sysreg.h"
+#include "synchronization.h"
+
+static void enableDebugTraps(void)
+{
+    u64 mdcr = GET_SYSREG(mdcr_el2);
+
+    // Trap Debug Exceptions, and accesses to debug registers.
+    mdcr |= MDCR_EL2_TDE;
+
+    // Implied from TDE
+    mdcr |= MDCR_EL2_TDRA | MDCR_EL2_TDOSA | MDCR_EL2_TDA;
+
+    SET_SYSREG(mdcr_el2, mdcr);
+}
 
 void enableTraps(void)
 {
@@ -17,4 +47,6 @@ void enableTraps(void)
     // TODO debug exceptions
 
     SET_SYSREG(hcr_el2, hcr);
-}
+
+    enableDebugTraps();
+}