blob: 65ef5d2a49bdb240c5d7001e417801085f519943 [file] [log] [blame]
// 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.
#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(), hdlc_channel_output);
}
}
}
}
} // namespace pw::rpc::system_server