| // Copyright 2022 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. |
| |
| #include <cstddef> |
| |
| #include "pw_hdlc/encoded_size.h" |
| #include "pw_hdlc/rpc_channel.h" |
| #include "pw_hdlc/rpc_packets.h" |
| #include "pw_log/log.h" |
| #include "pw_rpc_system_server/rpc_server.h" |
| #include "pw_stream/sys_io_stream.h" |
| |
| namespace pw::rpc::system_server { |
| namespace { |
| |
| // Hard-coded to 1055 bytes, which is enough to fit 512-byte payloads when using |
| // HDLC framing. |
| constexpr size_t kMaxTransmissionUnit = 1055; |
| |
| static_assert(kMaxTransmissionUnit == |
| hdlc::MaxEncodedFrameSize(rpc::cfg::kEncodingBufferSizeBytes)); |
| |
| // Used to write HDLC data to pw::sys_io. |
| stream::SysIoWriter writer; |
| stream::SysIoReader reader; |
| |
| // Set up the output channel for the pw_rpc server to use. |
| hdlc::FixedMtuChannelOutput<kMaxTransmissionUnit> hdlc_channel_output( |
| writer, pw::hdlc::kDefaultRpcAddress, "HDLC channel"); |
| Channel channels[] = {pw::rpc::Channel::Create<1>(&hdlc_channel_output)}; |
| rpc::Server server(channels); |
| |
| } // namespace |
| |
| void Init() { |
| // Send log messages to HDLC address 1. This prevents logs from interfering |
| // with pw_rpc communications. |
| pw::log_basic::SetOutput([](std::string_view log) { |
| pw::hdlc::WriteUIFrame(1, as_bytes(span(log)), writer); |
| }); |
| } |
| |
| rpc::Server& Server() { return server; } |
| |
| Status Start() { |
| constexpr size_t kDecoderBufferSize = |
| hdlc::Decoder::RequiredBufferSizeForFrameSize(kMaxTransmissionUnit); |
| // Declare a buffer for decoding incoming HDLC frames. |
| std::array<std::byte, kDecoderBufferSize> input_buffer; |
| hdlc::Decoder decoder(input_buffer); |
| |
| while (true) { |
| std::byte byte; |
| Status ret_val = pw::sys_io::ReadByte(&byte); |
| if (!ret_val.ok()) { |
| return ret_val; |
| } |
| if (auto result = decoder.Process(byte); result.ok()) { |
| hdlc::Frame& frame = result.value(); |
| if (frame.address() == hdlc::kDefaultRpcAddress) { |
| server.ProcessPacket(frame.data()); |
| } |
| } |
| } |
| } |
| |
| } // namespace pw::rpc::system_server |