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 <mtdutils.h> 24 25 #include "update_engine/payload_consumer/file_descriptor.h" 26 27 namespace chromeos_update_engine { 28 29 // A class defining the file descriptor API for raw MTD device. This file 30 // descriptor supports either random read, or sequential write but not both at 31 // once. 32 class MtdFileDescriptor : public EintrSafeFileDescriptor { 33 public: 34 MtdFileDescriptor(); 35 36 static bool IsMtd(const char* path); 37 38 bool Open(const char* path, int flags, mode_t mode) override; 39 bool Open(const char* path, int flags) override; 40 ssize_t Read(void* buf, size_t count) override; 41 ssize_t Write(const void* buf, size_t count) override; 42 off64_t Seek(off64_t offset, int whence) override; BlockDevSize()43 uint64_t BlockDevSize() override { return 0; } BlkIoctl(int request,uint64_t start,uint64_t length,int * result)44 bool BlkIoctl(int request, 45 uint64_t start, 46 uint64_t length, 47 int* result) override { 48 return false; 49 } 50 bool Close() override; 51 52 private: 53 std::unique_ptr<MtdReadContext, decltype(&mtd_read_close)> read_ctx_; 54 std::unique_ptr<MtdWriteContext, decltype(&mtd_write_close)> write_ctx_; 55 uint64_t nr_written_; 56 }; 57 58 struct UbiVolumeInfo { 59 // Number of eraseblocks. 60 uint64_t reserved_ebs; 61 // Size of each eraseblock. 62 uint64_t eraseblock_size; 63 }; 64 65 // A file descriptor to update a UBI volume, similar to MtdFileDescriptor. 66 // Once the file descriptor is opened for write, the volume is marked as being 67 // updated. The volume will not be usable until an update is completed. See 68 // UBI_IOCVOLUP ioctl operation. 69 class UbiFileDescriptor : public EintrSafeFileDescriptor { 70 public: 71 // Perform some queries about |path| to see if it is a UBI volume. 72 static bool IsUbi(const char* path); 73 74 bool Open(const char* path, int flags, mode_t mode) override; 75 bool Open(const char* path, int flags) override; 76 ssize_t Read(void* buf, size_t count) override; 77 ssize_t Write(const void* buf, size_t count) override; 78 off64_t Seek(off64_t offset, int whence) override; BlockDevSize()79 uint64_t BlockDevSize() override { return 0; } BlkIoctl(int request,uint64_t start,uint64_t length,int * result)80 bool BlkIoctl(int request, 81 uint64_t start, 82 uint64_t length, 83 int* result) override { 84 return false; 85 } 86 bool Close() override; 87 88 private: 89 enum Mode { 90 kReadOnly, 91 kWriteOnly 92 }; 93 94 uint64_t usable_eb_blocks_; 95 uint64_t eraseblock_size_; 96 uint64_t volume_size_; 97 uint64_t nr_written_; 98 99 Mode mode_; 100 }; 101 102 } // namespace chromeos_update_engine 103 104 #endif // UPDATE_ENGINE_PAYLOAD_CONSUMER_MTD_FILE_DESCRIPTOR_H_ 105