77 lines
2.6 KiB
C++
77 lines
2.6 KiB
C++
/*
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* Copyright (C) 2015 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include <stdio.h>
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#include <string>
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#include "fs_mgr.h"
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#include "fs_mgr_priv.h"
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// Realistically, this file should be part of the android::fs_mgr namespace;
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using namespace android::fs_mgr;
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// https://source.android.com/devices/tech/ota/ab/ab_implement#partitions
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// All partitions that are A/B-ed should be named as follows (slots are always
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// named a, b, etc.): boot_a, boot_b, system_a, system_b, vendor_a, vendor_b.
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static std::string other_suffix(const std::string& slot_suffix) {
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if (slot_suffix == "_a") {
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return "_b";
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}
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if (slot_suffix == "_b") {
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return "_a";
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}
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return "";
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}
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// Returns "_b" or "_a", which is *the other* slot of androidboot.slot_suffix
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// in kernel cmdline, or an empty string if that parameter does not exist.
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std::string fs_mgr_get_other_slot_suffix() {
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return other_suffix(fs_mgr_get_slot_suffix());
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}
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// Returns "_a" or "_b" based on androidboot.slot_suffix in kernel cmdline, or an empty string
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// if that parameter does not exist.
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std::string fs_mgr_get_slot_suffix() {
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std::string ab_suffix;
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fs_mgr_get_boot_config("slot_suffix", &ab_suffix);
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return ab_suffix;
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}
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// Updates |fstab| for slot_suffix. Returns true on success, false on error.
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bool fs_mgr_update_for_slotselect(Fstab* fstab) {
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std::string ab_suffix;
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for (auto& entry : *fstab) {
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if (!entry.fs_mgr_flags.slot_select && !entry.fs_mgr_flags.slot_select_other) {
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continue;
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}
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if (ab_suffix.empty()) {
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ab_suffix = fs_mgr_get_slot_suffix();
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// Return false if failed to get ab_suffix when MF_SLOTSELECT is specified.
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if (ab_suffix.empty()) return false;
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}
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const auto& update_suffix =
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entry.fs_mgr_flags.slot_select ? ab_suffix : other_suffix(ab_suffix);
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entry.blk_device = entry.blk_device + update_suffix;
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entry.logical_partition_name = entry.logical_partition_name + update_suffix;
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}
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return true;
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}
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