first cut: establishes base helper classes and main

developer_switch.h

+// 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.
+//
+// Concrete class for DeveloperSwitch.  This class represents the physical
+// developer mode switch on the Chrome OS device and maps its value to
+// kEnabled, kDisabled, and kUnsupported as per PlatformSwitch.
+//
+// The developer mode switch shares a file in /sys which is provided by
+// chromeos_acpi for the x86 plaform (ARM TBD).  The file contains an integer
+// in ASCII format (-1, 0, 544, whatever) with one bit representing a
+// platform switch value.  The developer switch is allocated the 6th
+// bit (0x20).  The file in use (CHSW) indicates the boot-time position
+// of the switch and not a current measurement (available in GPIO.* files).
+#ifndef CROS_BOOT_MODE_DEVELOPER_SWITCH_H_
+#define CROS_BOOT_MODE_DEVELOPER_SWITCH_H_
+
+#include "platform_switch.h"
+
+namespace cros_boot_mode {
+
+class DeveloperSwitch : public PlatformSwitch {
+ public:
+  DeveloperSwitch();
+  virtual ~DeveloperSwitch();
+  virtual const char *name() const {
+    return "developer";
+  }
+  virtual unsigned int bitmask() const {
+    return 0x00000020;  // specified in the firmware spec.
+  }
+};
+
+}  // namespace cros_boot_mode
+#endif  // CROS_BOOT_MODE_DEVELOPER_SWITCH_H_