exo/mariko fatal: save fatal error binaries to the SD

exosphere/mariko_fatal/source/fatal_sdmmc_c.h

@@ -0,0 +1,28 @@
+/*
+ * 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 <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+bool sdmmc_read_sd_card(void *dst, size_t size, size_t sector_index, size_t sector_count);
+bool sdmmc_write_sd_card(size_t sector_index, size_t sector_count, const void *src, size_t size);
+
+#ifdef __cplusplus
+}
+#endif