| // Copyright (c) 2013 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. |
| |
| #include "update_engine/hardware.h" |
| |
| #include <base/logging.h> |
| #include <rootdev/rootdev.h> |
| |
| using std::string; |
| |
| namespace chromeos_update_engine { |
| |
| const string Hardware::BootDevice() { |
| char boot_path[PATH_MAX]; |
| // Resolve the boot device path fully, including dereferencing |
| // through dm-verity. |
| int ret = rootdev(boot_path, sizeof(boot_path), true, false); |
| |
| if (ret < 0) { |
| LOG(ERROR) << "rootdev failed to find the root device"; |
| return ""; |
| } |
| LOG_IF(WARNING, ret > 0) << "rootdev found a device name with no device node"; |
| |
| // This local variable is used to construct the return string and is not |
| // passed around after use. |
| return boot_path; |
| } |
| |
| const string Hardware::KernelDeviceOfBootDevice( |
| const std::string& boot_device) { |
| // Currently this assumes the last digit of the boot device is |
| // 3, 5, or 7, and changes it to 2, 4, or 6, respectively, to |
| // get the kernel device. |
| string ret = boot_device; |
| if (ret.empty()) |
| return ret; |
| char last_char = ret[ret.size() - 1]; |
| if (last_char == '3' || last_char == '5' || last_char == '7') { |
| ret[ret.size() - 1] = last_char - 1; |
| return ret; |
| } |
| return ""; |
| } |
| |
| } // namespace chromeos_update_engine |