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-rw-r--r--bootloader_message/bootloader_message.cpp180
1 files changed, 180 insertions, 0 deletions
diff --git a/bootloader_message/bootloader_message.cpp b/bootloader_message/bootloader_message.cpp
new file mode 100644
index 000000000..e0c95d223
--- /dev/null
+++ b/bootloader_message/bootloader_message.cpp
@@ -0,0 +1,180 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <bootloader_message/bootloader_message.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <string.h>
+
+#include <string>
+#include <vector>
+
+#include <android-base/file.h>
+#include <android-base/properties.h>
+#include <android-base/stringprintf.h>
+#include <android-base/unique_fd.h>
+#include <fs_mgr.h>
+
+static struct fstab* read_fstab(std::string* err) {
+ std::string ro_hardware = android::base::GetProperty("ro.hardware", "");
+ if (ro_hardware.empty()) {
+ *err = "failed to get ro.hardware";
+ return nullptr;
+ }
+ // The fstab path is always "/fstab.${ro.hardware}".
+ std::string fstab_path = "/fstab." + ro_hardware;
+ struct fstab* fstab = fs_mgr_read_fstab(fstab_path.c_str());
+ if (fstab == nullptr) {
+ *err = "failed to read " + fstab_path;
+ }
+ return fstab;
+}
+
+static std::string get_misc_blk_device(std::string* err) {
+ struct fstab* fstab = read_fstab(err);
+ if (fstab == nullptr) {
+ return "";
+ }
+ fstab_rec* record = fs_mgr_get_entry_for_mount_point(fstab, "/misc");
+ if (record == nullptr) {
+ *err = "failed to find /misc partition";
+ return "";
+ }
+ return record->blk_device;
+}
+
+// In recovery mode, recovery can get started and try to access the misc
+// device before the kernel has actually created it.
+static bool wait_for_device(const std::string& blk_device, std::string* err) {
+ int tries = 0;
+ int ret;
+ err->clear();
+ do {
+ ++tries;
+ struct stat buf;
+ ret = stat(blk_device.c_str(), &buf);
+ if (ret == -1) {
+ *err += android::base::StringPrintf("failed to stat %s try %d: %s\n",
+ blk_device.c_str(), tries, strerror(errno));
+ sleep(1);
+ }
+ } while (ret && tries < 10);
+
+ if (ret) {
+ *err += android::base::StringPrintf("failed to stat %s\n", blk_device.c_str());
+ }
+ return ret == 0;
+}
+
+static bool read_misc_partition(void* p, size_t size, size_t offset, std::string* err) {
+ std::string misc_blk_device = get_misc_blk_device(err);
+ if (misc_blk_device.empty()) {
+ return false;
+ }
+ if (!wait_for_device(misc_blk_device, err)) {
+ return false;
+ }
+ android::base::unique_fd fd(open(misc_blk_device.c_str(), O_RDONLY));
+ if (fd.get() == -1) {
+ *err = android::base::StringPrintf("failed to open %s: %s", misc_blk_device.c_str(),
+ strerror(errno));
+ return false;
+ }
+ if (lseek(fd.get(), static_cast<off_t>(offset), SEEK_SET) != static_cast<off_t>(offset)) {
+ *err = android::base::StringPrintf("failed to lseek %s: %s", misc_blk_device.c_str(),
+ strerror(errno));
+ return false;
+ }
+ if (!android::base::ReadFully(fd.get(), p, size)) {
+ *err = android::base::StringPrintf("failed to read %s: %s", misc_blk_device.c_str(),
+ strerror(errno));
+ return false;
+ }
+ return true;
+}
+
+static bool write_misc_partition(const void* p, size_t size, size_t offset, std::string* err) {
+ std::string misc_blk_device = get_misc_blk_device(err);
+ if (misc_blk_device.empty()) {
+ return false;
+ }
+ android::base::unique_fd fd(open(misc_blk_device.c_str(), O_WRONLY | O_SYNC));
+ if (fd.get() == -1) {
+ *err = android::base::StringPrintf("failed to open %s: %s", misc_blk_device.c_str(),
+ strerror(errno));
+ return false;
+ }
+ if (lseek(fd.get(), static_cast<off_t>(offset), SEEK_SET) != static_cast<off_t>(offset)) {
+ *err = android::base::StringPrintf("failed to lseek %s: %s", misc_blk_device.c_str(),
+ strerror(errno));
+ return false;
+ }
+ if (!android::base::WriteFully(fd.get(), p, size)) {
+ *err = android::base::StringPrintf("failed to write %s: %s", misc_blk_device.c_str(),
+ strerror(errno));
+ return false;
+ }
+
+ // TODO: O_SYNC and fsync duplicates each other?
+ if (fsync(fd.get()) == -1) {
+ *err = android::base::StringPrintf("failed to fsync %s: %s", misc_blk_device.c_str(),
+ strerror(errno));
+ return false;
+ }
+ return true;
+}
+
+bool read_bootloader_message(bootloader_message* boot, std::string* err) {
+ return read_misc_partition(boot, sizeof(*boot), BOOTLOADER_MESSAGE_OFFSET_IN_MISC, err);
+}
+
+bool write_bootloader_message(const bootloader_message& boot, std::string* err) {
+ return write_misc_partition(&boot, sizeof(boot), BOOTLOADER_MESSAGE_OFFSET_IN_MISC, err);
+}
+
+bool clear_bootloader_message(std::string* err) {
+ bootloader_message boot = {};
+ return write_bootloader_message(boot, err);
+}
+
+bool write_bootloader_message(const std::vector<std::string>& options, std::string* err) {
+ bootloader_message boot = {};
+ strlcpy(boot.command, "boot-recovery", sizeof(boot.command));
+ strlcpy(boot.recovery, "recovery\n", sizeof(boot.recovery));
+ for (const auto& s : options) {
+ strlcat(boot.recovery, s.c_str(), sizeof(boot.recovery));
+ if (s.back() != '\n') {
+ strlcat(boot.recovery, "\n", sizeof(boot.recovery));
+ }
+ }
+ return write_bootloader_message(boot, err);
+}
+
+bool read_wipe_package(std::string* package_data, size_t size, std::string* err) {
+ package_data->resize(size);
+ return read_misc_partition(&(*package_data)[0], size, WIPE_PACKAGE_OFFSET_IN_MISC, err);
+}
+
+bool write_wipe_package(const std::string& package_data, std::string* err) {
+ return write_misc_partition(package_data.data(), package_data.size(),
+ WIPE_PACKAGE_OFFSET_IN_MISC, err);
+}
+
+extern "C" bool write_bootloader_message(const char* options) {
+ std::string err;
+ return write_bootloader_message({options}, &err);
+}