1//
2// Copyright (C) 2015 The Android Open Source Project
3//
4// Licensed under the Apache License, Version 2.0 (the "License");
5// you may not use this file except in compliance with the License.
6// You may obtain a copy of the License at
7//
8//      http://www.apache.org/licenses/LICENSE-2.0
9//
10// Unless required by applicable law or agreed to in writing, software
11// distributed under the License is distributed on an "AS IS" BASIS,
12// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13// See the License for the specific language governing permissions and
14// limitations under the License.
15//
16
17#include "update_engine/boot_control_android.h"
18
19#include <base/bind.h>
20#include <base/files/file_util.h>
21#include <base/logging.h>
22#include <base/strings/string_util.h>
23#include <brillo/make_unique_ptr.h>
24#include <brillo/message_loops/message_loop.h>
25
26#include "update_engine/common/utils.h"
27#include "update_engine/utils_android.h"
28
29using std::string;
30
31#ifdef _UE_SIDELOAD
32// When called from update_engine_sideload, we don't attempt to dynamically load
33// the right boot_control HAL, instead we use the only HAL statically linked in
34// via the PRODUCT_STATIC_BOOT_CONTROL_HAL make variable and access the module
35// struct directly.
36extern const hw_module_t HAL_MODULE_INFO_SYM;
37#endif  // _UE_SIDELOAD
38
39namespace chromeos_update_engine {
40
41namespace boot_control {
42
43// Factory defined in boot_control.h.
44std::unique_ptr<BootControlInterface> CreateBootControl() {
45  std::unique_ptr<BootControlAndroid> boot_control(new BootControlAndroid());
46  if (!boot_control->Init()) {
47    return nullptr;
48  }
49  return brillo::make_unique_ptr(boot_control.release());
50}
51
52}  // namespace boot_control
53
54bool BootControlAndroid::Init() {
55  const hw_module_t* hw_module;
56  int ret;
57
58#ifdef _UE_SIDELOAD
59  // For update_engine_sideload, we simulate the hw_get_module() by accessing it
60  // from the current process directly.
61  hw_module = &HAL_MODULE_INFO_SYM;
62  ret = 0;
63  if (!hw_module ||
64      strcmp(BOOT_CONTROL_HARDWARE_MODULE_ID, hw_module->id) != 0) {
65    ret = -EINVAL;
66  }
67#else  // !_UE_SIDELOAD
68  ret = hw_get_module(BOOT_CONTROL_HARDWARE_MODULE_ID, &hw_module);
69#endif  // _UE_SIDELOAD
70  if (ret != 0) {
71    LOG(ERROR) << "Error loading boot_control HAL implementation.";
72    return false;
73  }
74
75  module_ = reinterpret_cast<boot_control_module_t*>(const_cast<hw_module_t*>(hw_module));
76  module_->init(module_);
77
78  LOG(INFO) << "Loaded boot_control HAL "
79            << "'" << hw_module->name << "' "
80            << "version " << (hw_module->module_api_version>>8) << "."
81            << (hw_module->module_api_version&0xff) << " "
82            << "authored by '" << hw_module->author << "'.";
83  return true;
84}
85
86unsigned int BootControlAndroid::GetNumSlots() const {
87  return module_->getNumberSlots(module_);
88}
89
90BootControlInterface::Slot BootControlAndroid::GetCurrentSlot() const {
91  return module_->getCurrentSlot(module_);
92}
93
94bool BootControlAndroid::GetPartitionDevice(const string& partition_name,
95                                            Slot slot,
96                                            string* device) const {
97  // We can't use fs_mgr to look up |partition_name| because fstab
98  // doesn't list every slot partition (it uses the slotselect option
99  // to mask the suffix).
100  //
101  // We can however assume that there's an entry for the /misc mount
102  // point and use that to get the device file for the misc
103  // partition. This helps us locate the disk that |partition_name|
104  // resides on. From there we'll assume that a by-name scheme is used
105  // so we can just replace the trailing "misc" by the given
106  // |partition_name| and suffix corresponding to |slot|, e.g.
107  //
108  //   /dev/block/platform/soc.0/7824900.sdhci/by-name/misc ->
109  //   /dev/block/platform/soc.0/7824900.sdhci/by-name/boot_a
110  //
111  // If needed, it's possible to relax the by-name assumption in the
112  // future by trawling /sys/block looking for the appropriate sibling
113  // of misc and then finding an entry in /dev matching the sysfs
114  // entry.
115
116  base::FilePath misc_device;
117  if (!utils::DeviceForMountPoint("/misc", &misc_device))
118    return false;
119
120  if (!utils::IsSymlink(misc_device.value().c_str())) {
121    LOG(ERROR) << "Device file " << misc_device.value() << " for /misc "
122               << "is not a symlink.";
123    return false;
124  }
125
126  const char* suffix = module_->getSuffix(module_, slot);
127  if (suffix == nullptr) {
128    LOG(ERROR) << "boot_control impl returned no suffix for slot "
129               << SlotName(slot);
130    return false;
131  }
132
133  base::FilePath path = misc_device.DirName().Append(partition_name + suffix);
134  if (!base::PathExists(path)) {
135    LOG(ERROR) << "Device file " << path.value() << " does not exist.";
136    return false;
137  }
138
139  *device = path.value();
140  return true;
141}
142
143bool BootControlAndroid::IsSlotBootable(Slot slot) const {
144  int ret = module_->isSlotBootable(module_, slot);
145  if (ret < 0) {
146    LOG(ERROR) << "Unable to determine if slot " << SlotName(slot)
147               << " is bootable: " << strerror(-ret);
148    return false;
149  }
150  return ret == 1;
151}
152
153bool BootControlAndroid::MarkSlotUnbootable(Slot slot) {
154  int ret = module_->setSlotAsUnbootable(module_, slot);
155  if (ret < 0) {
156    LOG(ERROR) << "Unable to mark slot " << SlotName(slot)
157               << " as bootable: " << strerror(-ret);
158    return false;
159  }
160  return ret == 0;
161}
162
163bool BootControlAndroid::SetActiveBootSlot(Slot slot) {
164  int ret = module_->setActiveBootSlot(module_, slot);
165  if (ret < 0) {
166    LOG(ERROR) << "Unable to set the active slot to slot " << SlotName(slot)
167               << ": " << strerror(-ret);
168  }
169  return ret == 0;
170}
171
172bool BootControlAndroid::MarkBootSuccessfulAsync(
173    base::Callback<void(bool)> callback) {
174  int ret = module_->markBootSuccessful(module_);
175  if (ret < 0) {
176    LOG(ERROR) << "Unable to mark boot successful: " << strerror(-ret);
177  }
178  return brillo::MessageLoop::current()->PostTask(
179             FROM_HERE, base::Bind(callback, ret == 0)) !=
180         brillo::MessageLoop::kTaskIdNull;
181}
182
183}  // namespace chromeos_update_engine
184