1 // 2 // Copyright (C) 2014 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 #ifndef UPDATE_ENGINE_PAYLOAD_CONSUMER_MTD_FILE_DESCRIPTOR_H_ 18 #define UPDATE_ENGINE_PAYLOAD_CONSUMER_MTD_FILE_DESCRIPTOR_H_ 19 20 // This module defines file descriptors that deal with NAND media. We are 21 // concerned with raw NAND access (as MTD device), and through UBI layer. 22 23 #include <memory> 24 25 #include <mtdutils.h> 26 27 #include "update_engine/payload_consumer/file_descriptor.h" 28 29 namespace chromeos_update_engine { 30 31 // A class defining the file descriptor API for raw MTD device. This file 32 // descriptor supports either random read, or sequential write but not both at 33 // once. 34 class MtdFileDescriptor : public EintrSafeFileDescriptor { 35 public: 36 MtdFileDescriptor(); 37 38 static bool IsMtd(const char* path); 39 40 bool Open(const char* path, int flags, mode_t mode) override; 41 bool Open(const char* path, int flags) override; 42 ssize_t Read(void* buf, size_t count) override; 43 ssize_t Write(const void* buf, size_t count) override; 44 off64_t Seek(off64_t offset, int whence) override; BlockDevSize()45 uint64_t BlockDevSize() override { return 0; } BlkIoctl(int request,uint64_t start,uint64_t length,int * result)46 bool BlkIoctl(int request, 47 uint64_t start, 48 uint64_t length, 49 int* result) override { 50 return false; 51 } 52 bool Close() override; 53 54 private: 55 std::unique_ptr<MtdReadContext, decltype(&mtd_read_close)> read_ctx_; 56 std::unique_ptr<MtdWriteContext, decltype(&mtd_write_close)> write_ctx_; 57 uint64_t nr_written_; 58 }; 59 60 struct UbiVolumeInfo { 61 // Number of eraseblocks. 62 uint64_t reserved_ebs; 63 // Size of each eraseblock. 64 uint64_t eraseblock_size; 65 }; 66 67 // A file descriptor to update a UBI volume, similar to MtdFileDescriptor. 68 // Once the file descriptor is opened for write, the volume is marked as being 69 // updated. The volume will not be usable until an update is completed. See 70 // UBI_IOCVOLUP ioctl operation. 71 class UbiFileDescriptor : public EintrSafeFileDescriptor { 72 public: 73 // Perform some queries about |path| to see if it is a UBI volume. 74 static bool IsUbi(const char* path); 75 76 bool Open(const char* path, int flags, mode_t mode) override; 77 bool Open(const char* path, int flags) override; 78 ssize_t Read(void* buf, size_t count) override; 79 ssize_t Write(const void* buf, size_t count) override; 80 off64_t Seek(off64_t offset, int whence) override; BlockDevSize()81 uint64_t BlockDevSize() override { return 0; } BlkIoctl(int request,uint64_t start,uint64_t length,int * result)82 bool BlkIoctl(int request, 83 uint64_t start, 84 uint64_t length, 85 int* result) override { 86 return false; 87 } 88 bool Close() override; 89 90 private: 91 enum Mode { kReadOnly, kWriteOnly }; 92 93 uint64_t usable_eb_blocks_; 94 uint64_t eraseblock_size_; 95 uint64_t volume_size_; 96 uint64_t nr_written_; 97 98 Mode mode_; 99 }; 100 101 } // namespace chromeos_update_engine 102 103 #endif // UPDATE_ENGINE_PAYLOAD_CONSUMER_MTD_FILE_DESCRIPTOR_H_ 104