| // Copyright 2020 The Pigweed Authors |
| // |
| // 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 |
| // |
| // https://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. |
| |
| #define PW_LOG_MODULE_NAME "KVS" |
| |
| #include "pw_kvs/flash_memory.h" |
| |
| #include <algorithm> |
| #include <cinttypes> |
| #include <cstring> |
| |
| #include "pw_kvs_private/macros.h" |
| #include "pw_log/log.h" |
| #include "pw_status/status_with_size.h" |
| |
| namespace pw::kvs { |
| |
| using std::byte; |
| |
| StatusWithSize FlashPartition::Output::DoWrite(std::span<const byte> data) { |
| TRY_WITH_SIZE(flash_.Write(address_, data)); |
| address_ += data.size(); |
| return StatusWithSize(data.size()); |
| } |
| |
| StatusWithSize FlashPartition::Input::DoRead(std::span<byte> data) { |
| StatusWithSize result = flash_.Read(address_, data); |
| address_ += result.size(); |
| return result; |
| } |
| |
| Status FlashPartition::Erase(Address address, size_t num_sectors) { |
| if (permission_ == PartitionPermission::kReadOnly) { |
| return Status::PERMISSION_DENIED; |
| } |
| |
| TRY(CheckBounds(address, num_sectors * sector_size_bytes())); |
| return flash_.Erase(PartitionToFlashAddress(address), num_sectors); |
| } |
| |
| StatusWithSize FlashPartition::Read(Address address, std::span<byte> output) { |
| TRY_WITH_SIZE(CheckBounds(address, output.size())); |
| return flash_.Read(PartitionToFlashAddress(address), output); |
| } |
| |
| StatusWithSize FlashPartition::Write(Address address, |
| std::span<const byte> data) { |
| if (permission_ == PartitionPermission::kReadOnly) { |
| return StatusWithSize::PERMISSION_DENIED; |
| } |
| TRY_WITH_SIZE(CheckBounds(address, data.size())); |
| return flash_.Write(PartitionToFlashAddress(address), data); |
| } |
| |
| Status FlashPartition::IsRegionErased(Address source_flash_address, |
| size_t length, |
| bool* is_erased) { |
| // Max alignment is artificial to keep the stack usage low for this |
| // function. Using 16 because it's the alignment of encrypted flash. |
| constexpr size_t kMaxAlignment = 16; |
| |
| // Relying on Read() to check address and len arguments. |
| if (is_erased == nullptr) { |
| return Status::INVALID_ARGUMENT; |
| } |
| const size_t alignment = alignment_bytes(); |
| if (alignment > kMaxAlignment || kMaxAlignment % alignment || |
| length % alignment) { |
| return Status::INVALID_ARGUMENT; |
| } |
| |
| byte buffer[kMaxAlignment]; |
| byte erased_pattern_buffer[kMaxAlignment]; |
| |
| size_t offset = 0; |
| std::memset(erased_pattern_buffer, |
| int(flash_.erased_memory_content()), |
| sizeof(erased_pattern_buffer)); |
| *is_erased = false; |
| while (length > 0u) { |
| // Check earlier that length is aligned, no need to round up |
| size_t read_size = std::min(sizeof(buffer), length); |
| TRY(Read(source_flash_address + offset, read_size, buffer).status()); |
| if (std::memcmp(buffer, erased_pattern_buffer, read_size)) { |
| // Detected memory chunk is not entirely erased |
| return Status::OK; |
| } |
| offset += read_size; |
| length -= read_size; |
| } |
| *is_erased = true; |
| return Status::OK; |
| } |
| |
| bool FlashPartition::AppearsErased(std::span<const byte> data) const { |
| for (byte b : data) { |
| if (b != flash_.erased_memory_content()) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| Status FlashPartition::CheckBounds(Address address, size_t length) const { |
| if (address + length > size_bytes()) { |
| PW_LOG_ERROR( |
| "Attempted out-of-bound flash memory access (address: %u length: %u)", |
| unsigned(address), |
| unsigned(length)); |
| return Status::OUT_OF_RANGE; |
| } |
| return Status::OK; |
| } |
| |
| } // namespace pw::kvs |