first cut: establishes base helper classes and main

platform_switch.cc

+// Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+//
+// Implements PlatformSwitch by reading in the switch file (CHSW) and converting
+// its contents to an unsigned integer which is bitwise-ANDed with the
+// subclass-defined bitmask().
+
+#include "platform_switch.h"
+
+#include "helpers.h"
+
+namespace cros_boot_mode {
+
+const char *PlatformSwitch::kPositionText[] = { "disabled", "enabled" };
+
+PlatformSwitch::PlatformSwitch() { }
+PlatformSwitch::~PlatformSwitch() { }
+
+const char *PlatformSwitch::c_str() const {
+  return (value() >= 0 ? kPositionText[value()] : "unsupported");
+}
+
+int PlatformSwitch::Process(const char *file_contents, size_t length) {
+  int read_int = helpers::to_int(file_contents, length);
+  if (read_int < 0)
+    return kUnsupported;
+  unsigned int position = static_cast<unsigned int>(read_int);
+  return !((position & bitmask()) == 0);
+}
+
+}  // namespace cros_boot_mode