boot: refactor battery checking to use new powctl apis

libraries/libstratosphere/source/cal/cal_fs_utils.cpp

@@ -0,0 +1,36 @@
+/*
+ * 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/>.
+ */
+#include <stratosphere.hpp>
+#include "cal_crc_utils.hpp"
+#include "cal_fs_utils.hpp"
+
+namespace ams::cal::impl {
+
+    Result ReadCalibrationBlock(s64 offset, void *dst, size_t block_size) {
+        /* Open the calibration binary partition. */
+        std::unique_ptr<fs::IStorage> storage;
+        R_TRY(fs::OpenBisPartition(std::addressof(storage), fs::BisPartitionId::CalibrationBinary));
+
+        /* Read data from the partition. */
+        R_TRY(storage->Read(offset, dst, block_size));
+
+        /* Validate the crc. */
+        R_TRY(ValidateCalibrationCrc(dst, block_size));
+
+        return ResultSuccess();
+    }
+
+}