fs.mitm: Add HANS-style redirection for System Data Archives.

stratosphere/fs_mitm/source/fsmitm_utils.cpp

@@ -0,0 +1,29 @@
+#include <switch.h>
+#include <stratosphere.hpp>
+#include <atomic>
+
+#include "fsmitm_utils.hpp"
+
+static FsFileSystem g_sd_filesystem;
+static bool g_has_initialized = false;
+
+static Result EnsureInitialized() {
+    if (g_has_initialized) {
+        return 0x0;
+    }
+    Result rc = fsMountSdcard(&g_sd_filesystem);
+    if (R_SUCCEEDED(rc)) {
+        g_has_initialized = true;
+    }
+    return rc;
+}
+
+Result Utils::OpenSdFile(const char *fn, int flags, FsFile *out) {
+    Result rc;
+    if (R_FAILED((rc = EnsureInitialized()))) {
+        return rc;
+    }
+    char path[FS_MAX_PATH];
+    strcpy(path, fn);
+    return fsFsOpenFile(&g_sd_filesystem, path, flags, out);
+}