tio: implement SdCardObserver (finishes sysmodule)

libraries/libstratosphere/include/stratosphere/fs/fs_i_event_notifier.hpp

@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2018-2020 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/>.
+ */
+#pragma once
+#include "fs_common.hpp"
+
+namespace ams::fs {
+
+    class IEventNotifier {
+        public:
+            virtual ~IEventNotifier() { /* ... */ }
+
+            Result BindEvent(os::SystemEventType *out, os::EventClearMode clear_mode) {
+                AMS_ASSERT(out != nullptr);
+                return this->DoBindEvent(out, clear_mode);
+            }
+        private:
+            virtual Result DoBindEvent(os::SystemEventType *out, os::EventClearMode clear_mode) = 0;
+    };
+
+}

libraries/libstratosphere/include/stratosphere/fs/fs_sd_card.hpp

@@ -18,8 +18,14 @@
 
 namespace ams::fs {
 
+    class IEventNotifier;
+
     Result MountSdCard(const char *name);
 
     Result MountSdCardErrorReportDirectoryForAtmosphere(const char *name);
 
+    Result OpenSdCardDetectionEventNotifier(std::unique_ptr<IEventNotifier> *out);
+
+    bool IsSdCardInserted();
+
 }