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
29 using 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.
36 extern const hw_module_t HAL_MODULE_INFO_SYM;
37 #endif // _UE_SIDELOAD
38
39 namespace chromeos_update_engine {
40
41 namespace boot_control {
42
43 // Factory defined in boot_control.h.
CreateBootControl()44 std::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
Init()54 bool 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
GetNumSlots() const86 unsigned int BootControlAndroid::GetNumSlots() const {
87 return module_->getNumberSlots(module_);
88 }
89
GetCurrentSlot() const90 BootControlInterface::Slot BootControlAndroid::GetCurrentSlot() const {
91 return module_->getCurrentSlot(module_);
92 }
93
GetPartitionDevice(const string & partition_name,Slot slot,string * device) const94 bool 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
IsSlotBootable(Slot slot) const143 bool 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
MarkSlotUnbootable(Slot slot)153 bool 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
SetActiveBootSlot(Slot slot)163 bool 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
MarkBootSuccessfulAsync(base::Callback<void (bool)> callback)172 bool 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