Merge pull request 'Filesystem and CFDP updates' (#34) from filesystem-api-update into main

Reviewed-on: #34

.clang-format

@@ -4,4 +4,5 @@ IndentWidth: 2
 ---
 Language: Cpp
 ColumnLimit: 100
+ReflowComments: true
 ---

.gitignore

@@ -2,7 +2,7 @@
 .idea/*
 !/.idea/runConfigurations
 !/.idea/cmake.xml
-!/.idea/codeStyles
+# !/.idea/codeStyles
 
 # Eclipse
 .cproject

.idea/codeStyles/Project.xml

@@ -1,14 +0,0 @@
-<component name="ProjectCodeStyleConfiguration">
-  <code_scheme name="Project" version="173">
-    <clangFormatSettings>
-      <option name="ENABLED" value="true" />
-    </clangFormatSettings>
-    <codeStyleSettings language="CMake">
-      <indentOptions>
-        <option name="INDENT_SIZE" value="2" />
-        <option name="CONTINUATION_INDENT_SIZE" value="0" />
-        <option name="TAB_SIZE" value="2" />
-      </indentOptions>
-    </codeStyleSettings>
-  </code_scheme>
-</component>

.idea/codeStyles/codeStyleConfig.xml

@@ -1,5 +0,0 @@
-<component name="ProjectCodeStyleConfiguration">
-  <state>
-    <option name="USE_PER_PROJECT_SETTINGS" value="true" />
-  </state>
-</component>

CHANGELOG.md

@@ -30,9 +30,13 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
   https://egit.irs.uni-stuttgart.de/fsfw/fsfw/pulls/742
 - `PusTmZcWriter` now exposes API to set message counter field.
 - Relative timeshift in the PUS time service.
+- CFDP support for PDU checksums
 
 ## Changed
 
+- Improved File System Abstraction to be more in line with normal filesystems.
+- CFDP implementation was improved, has now even less dependencies on other FSFW components
+  and allows one inserted packet per state machine call.
 - The PUS time service now dumps the time before setting a new time and after having set the
   time.
 - HK generation is now countdown based.

CMakeLists.txt

@@ -140,7 +140,7 @@ option(FSFW_ADD_SGP4_PROPAGATOR "Add SGP4 propagator code" OFF)
 set(FSFW_TEST_TGT fsfw-tests)
 set(FSFW_DUMMY_TGT fsfw-dummy)
 
-add_library(${LIB_FSFW_NAME})
+add_library(${LIB_FSFW_NAME} src/fsfw/cfdp/handler/PduPacketIF.h)
 
 if(IPO_SUPPORTED AND FSFW_ENABLE_IPO)
   set_property(TARGET ${LIB_FSFW_NAME} PROPERTY INTERPROCEDURAL_OPTIMIZATION
@@ -175,7 +175,10 @@ if(FSFW_BUILD_TESTS)
   configure_file(unittests/testcfg/TestsConfig.h.in tests/TestsConfig.h)
 
   project(${FSFW_TEST_TGT} CXX C)
-  add_executable(${FSFW_TEST_TGT})
+  add_executable(
+    ${FSFW_TEST_TGT}
+    unittests/cfdp/PduSenderMock.cpp unittests/cfdp/PduSenderMock.h
+    unittests/cfdp/handler/OwnedPduPacket.h)
   if(IPO_SUPPORTED AND FSFW_ENABLE_IPO)
     set_property(TARGET ${FSFW_TEST_TGT} PROPERTY INTERPROCEDURAL_OPTIMIZATION
                                                   TRUE)

src/fsfw/cfdp/CfdpDistributor.h

@@ -4,7 +4,7 @@
 #include <utility>
 #include <vector>
 
-#include "fsfw/cfdp/pdu/PduHeaderReader.h"
+#include "fsfw/cfdp/pdu/HeaderReader.h"
 #include "fsfw/returnvalues/returnvalue.h"
 #include "fsfw/tcdistribution/CfdpPacketChecker.h"
 #include "fsfw/tcdistribution/TcDistributorBase.h"

src/fsfw/cfdp/definitions.h

@@ -38,6 +38,7 @@ static constexpr ReturnValue_t FILESTORE_REQUIRES_SECOND_FILE =
 static constexpr ReturnValue_t FILESTORE_RESPONSE_CANT_PARSE_FS_MESSAGE =
     returnvalue::makeCode(CFDP_CLASS_ID, 9);
 static constexpr ReturnValue_t INVALID_PDU_FORMAT = returnvalue::makeCode(CFDP_CLASS_ID, 10);
+static constexpr ReturnValue_t PDU_CHECKSUM_FAILURE = returnvalue::makeCode(CFDP_CLASS_ID, 11);
 
 //! Checksum types according to the SANA Checksum Types registry
 //! https://sanaregistry.org/r/checksum_identifiers/

src/fsfw/cfdp/handler/DestHandler.cpp

@@ -8,14 +8,18 @@
 #include "fsfw/cfdp/pdu/EofPduReader.h"
 #include "fsfw/cfdp/pdu/FileDataReader.h"
 #include "fsfw/cfdp/pdu/FinishedPduCreator.h"
-#include "fsfw/cfdp/pdu/PduHeaderReader.h"
+#include "fsfw/cfdp/pdu/HeaderReader.h"
 #include "fsfw/objectmanager.h"
 #include "fsfw/tmtcservices/TmTcMessage.h"
 
 using namespace returnvalue;
 
-cfdp::DestHandler::DestHandler(DestHandlerParams params, FsfwParams fsfwParams)
+cfdp::DestHandler::DestHandler(PduSenderIF& pduSender, size_t pduBufSize, DestHandlerParams params,
-    : tlvVec(params.maxTlvsInOnePdu),
+                               FsfwParams fsfwParams)
+
+    : pduBuf(pduBufSize),
+      pduSender(pduSender),
+      tlvVec(params.maxTlvsInOnePdu),
       msgToUserVec(params.maxTlvsInOnePdu),
       transactionParams(params.maxFilenameLen),
       destParams(std::move(params)),
@@ -23,57 +27,44 @@ cfdp::DestHandler::DestHandler(DestHandlerParams params, FsfwParams fsfwParams)
   transactionParams.pduConf.direction = cfdp::Direction::TOWARDS_SENDER;
 }
 
-const cfdp::DestHandler::FsmResult& cfdp::DestHandler::stateMachine() {
+const cfdp::DestHandler::FsmResult& cfdp::DestHandler::stateMachineNoPacket() {
+  return stateMachine(std::nullopt);
+}
+const cfdp::DestHandler::FsmResult& cfdp::DestHandler::stateMachine(
+    const std::optional<std::reference_wrapper<PduPacketIF>> optPduPacket) {
   ReturnValue_t result;
   uint8_t errorIdx = 0;
   fsmRes.resetOfIteration();
   if (fsmRes.step == TransactionStep::IDLE) {
-    for (auto infoIter = destParams.packetListRef.begin();
+    if (!optPduPacket.has_value()) {
-         infoIter != destParams.packetListRef.end();) {
+      return fsmRes;
-      if (infoIter->pduType == PduType::FILE_DIRECTIVE and
+    }
-          infoIter->directiveType == FileDirective::METADATA) {
+    PduPacketIF& pduPacket = *optPduPacket;
-        result = handleMetadataPdu(*infoIter);
+    if (pduPacket.getPduType() == FILE_DATA or
+        (pduPacket.getPduType() == FILE_DIRECTIVE and *pduPacket.getFileDirective() != METADATA)) {
+      fsmRes.result = DEST_NON_METADATA_PDU_AS_FIRST_PDU;
+      return fsmRes;
+    }
+    result = handleMetadataPdu(pduPacket);
     checkAndHandleError(result, errorIdx);
-        // Store data was deleted in PDU handler because a store guard is used
-        destParams.packetListRef.erase(infoIter++);
-      } else {
-        infoIter++;
-      }
-    }
-    if (fsmRes.step == TransactionStep::IDLE) {
-      // To decrease the already high complexity of the software, all packets arriving before
-      // a metadata PDU are deleted.
-      for (auto infoIter = destParams.packetListRef.begin();
-           infoIter != destParams.packetListRef.end();) {
-        fsfwParams.tcStore->deleteData(infoIter->storeId);
-        infoIter++;
-      }
-      destParams.packetListRef.clear();
-    }
-
-    if (fsmRes.step != TransactionStep::IDLE) {
-      fsmRes.callStatus = CallStatus::CALL_AGAIN;
-    }
     return updateFsmRes(errorIdx);
   }
+
   if (fsmRes.state == CfdpState::BUSY_CLASS_1_NACKED) {
     if (fsmRes.step == TransactionStep::RECEIVING_FILE_DATA_PDUS) {
-      for (auto infoIter = destParams.packetListRef.begin();
+      if (!optPduPacket.has_value()) {
-           infoIter != destParams.packetListRef.end();) {
+        return fsmRes;
-        if (infoIter->pduType == PduType::FILE_DATA) {
+      }
-          result = handleFileDataPdu(*infoIter);
+      PduPacketIF& pduPacket = *optPduPacket;
+      if (pduPacket.getPduType() == FILE_DATA) {
+        result = handleFileDataPdu(pduPacket);
         checkAndHandleError(result, errorIdx);
-          // Store data was deleted in PDU handler because a store guard is used
+
-          destParams.packetListRef.erase(infoIter++);
+      } else if (pduPacket.getPduType() == FILE_DIRECTIVE and
-        } else if (infoIter->pduType == PduType::FILE_DIRECTIVE and
+                 *pduPacket.getFileDirective() == EOF_DIRECTIVE) {
-                   infoIter->directiveType == FileDirective::EOF_DIRECTIVE) {
         // TODO: Support for check timer missing
-          result = handleEofPdu(*infoIter);
+        result = handleEofPdu(pduPacket);
         checkAndHandleError(result, errorIdx);
-          // Store data was deleted in PDU handler because a store guard is used
-          destParams.packetListRef.erase(infoIter++);
-        } else {
-          infoIter++;
       }
     }
   }
@@ -85,7 +76,6 @@ const cfdp::DestHandler::FsmResult& cfdp::DestHandler::stateMachine() {
     result = sendFinishedPdu();
     checkAndHandleError(result, errorIdx);
     finish();
-    }
     return updateFsmRes(errorIdx);
   }
   if (fsmRes.state == CfdpState::BUSY_CLASS_2_ACKED) {
@@ -97,75 +87,37 @@ const cfdp::DestHandler::FsmResult& cfdp::DestHandler::stateMachine() {
   return updateFsmRes(errorIdx);
 }
 
-ReturnValue_t cfdp::DestHandler::passPacket(PacketInfo packet) {
+ReturnValue_t cfdp::DestHandler::handleMetadataPdu(const PduPacketIF& pduPacket) {
-  if (destParams.packetListRef.full()) {
-    return FAILED;
-  }
-  destParams.packetListRef.push_back(packet);
-  return OK;
-}
-
-ReturnValue_t cfdp::DestHandler::initialize() {
-  if (fsfwParams.tmStore == nullptr) {
-    fsfwParams.tmStore = ObjectManager::instance()->get<StorageManagerIF>(objects::TM_STORE);
-    if (fsfwParams.tmStore == nullptr) {
-      return FAILED;
-    }
-  }
-
-  if (fsfwParams.tcStore == nullptr) {
-    fsfwParams.tcStore = ObjectManager::instance()->get<StorageManagerIF>(objects::TC_STORE);
-    if (fsfwParams.tcStore == nullptr) {
-      return FAILED;
-    }
-  }
-
-  if (fsfwParams.msgQueue == nullptr) {
-    return FAILED;
-  }
-  return OK;
-}
-
-ReturnValue_t cfdp::DestHandler::handleMetadataPdu(const PacketInfo& info) {
   // Process metadata PDU
-  auto constAccessorPair = fsfwParams.tcStore->getData(info.storeId);
-  if (constAccessorPair.first != OK) {
-    // TODO: This is not a CFDP error. Event and/or warning?
-    return constAccessorPair.first;
-  }
   cfdp::StringLv sourceFileName;
   cfdp::StringLv destFileName;
+
   MetadataGenericInfo metadataInfo(transactionParams.fileSize);
-  MetadataPduReader reader(constAccessorPair.second.data(), constAccessorPair.second.size(),
+  size_t pduSize = 0;
-                           metadataInfo, tlvVec.data(), tlvVec.size());
+  auto rawPdu = pduPacket.getRawPduData(pduSize);
+  MetadataPduReader reader(rawPdu, pduSize, metadataInfo, tlvVec.data(), tlvVec.size());
   ReturnValue_t result = reader.parseData();
   // TODO: The standard does not really specify what happens if this kind of error happens
   //       I think it might be a good idea to cache some sort of error code, which
   //       is translated into a warning and/or event by an upper layer
   if (result != OK) {
-    return handleMetadataParseError(result, constAccessorPair.second.data(),
+    return handleMetadataParseError(result, rawPdu, pduSize);
-                                    constAccessorPair.second.size());
   }
   return startTransaction(reader);
 }
 
-ReturnValue_t cfdp::DestHandler::handleFileDataPdu(const cfdp::PacketInfo& info) {
+ReturnValue_t cfdp::DestHandler::handleFileDataPdu(const PduPacketIF& info) {
+  size_t pduSize = 0;
+  const auto rawPdu = info.getRawPduData(pduSize);
   // Process file data PDU
-  auto constAccessorPair = fsfwParams.tcStore->getData(info.storeId);
-  if (constAccessorPair.first != OK) {
-    // TODO: This is not a CFDP error. Event and/or warning?
-    return constAccessorPair.first;
-  }
   FileDataInfo fdInfo;
-  FileDataReader reader(constAccessorPair.second.data(), constAccessorPair.second.size(), fdInfo);
+  FileDataReader reader(rawPdu, pduSize, fdInfo);
   ReturnValue_t result = reader.parseData();
   if (result != OK) {
     return result;
   }
   size_t fileSegmentLen = 0;
   const uint8_t* fileData = fdInfo.getFileData(&fileSegmentLen);
-  FileOpParams fileOpParams(transactionParams.destName.data(), fileSegmentLen);
-  fileOpParams.offset = fdInfo.getOffset().value();
   if (destParams.cfg.indicCfg.fileSegmentRecvIndicRequired) {
     FileSegmentRecvdParams segParams;
     segParams.offset = fdInfo.getOffset().value();
@@ -177,7 +129,9 @@ ReturnValue_t cfdp::DestHandler::handleFileDataPdu(const cfdp::PacketInfo& info)
     segParams.segmentMetadata = {segMetadata, segmentMetadatLen};
     destParams.user.fileSegmentRecvdIndication(segParams);
   }
-  result = destParams.user.vfs.writeToFile(fileOpParams, fileData);
+  // sif::printDebug("Writing %d bytes at offset %d\n", fileSegmentLen, fdInfo.getOffset().value());
+  result = destParams.user.vfs.writeToFile(transactionParams.destName.data(),
+                                           fdInfo.getOffset().value(), fileData, fileSegmentLen);
   if (result != returnvalue::OK) {
     // TODO: Proper Error handling
 #if FSFW_CPP_OSTREAM_ENABLED == 1
@@ -191,25 +145,21 @@ ReturnValue_t cfdp::DestHandler::handleFileDataPdu(const cfdp::PacketInfo& info)
                                              static_cast<uint8_t>(fsmRes.step), result);
     }
     return result;
-  } else {
+  }
   transactionParams.deliveryStatus = FileDeliveryStatus::RETAINED_IN_FILESTORE;
   transactionParams.vfsErrorCount = 0;
-  }
   if (fdInfo.getOffset().value() + fileSegmentLen > transactionParams.progress) {
     transactionParams.progress = fdInfo.getOffset().value() + fileSegmentLen;
   }
   return result;
 }
 
-ReturnValue_t cfdp::DestHandler::handleEofPdu(const cfdp::PacketInfo& info) {
+ReturnValue_t cfdp::DestHandler::handleEofPdu(const cfdp::PduPacketIF& info) {
+  size_t pduSize = 0;
+  const auto rawPdu = info.getRawPduData(pduSize);
   // Process EOF PDU
-  auto constAccessorPair = fsfwParams.tcStore->getData(info.storeId);
-  if (constAccessorPair.first != OK) {
-    // TODO: This is not a CFDP error. Event and/or warning?
-    return constAccessorPair.first;
-  }
   EofInfo eofInfo(nullptr);
-  EofPduReader reader(constAccessorPair.second.data(), constAccessorPair.second.size(), eofInfo);
+  EofPduReader reader(rawPdu, pduSize, eofInfo);
   ReturnValue_t result = reader.parseData();
   if (result != OK) {
     return result;
@@ -244,6 +194,7 @@ ReturnValue_t cfdp::DestHandler::handleMetadataParseError(ReturnValue_t result,
 #if FSFW_CPP_OSTREAM_ENABLED == 1
   sif::warning << "Parsing Metadata PDU failed with code " << result << std::endl;
 #else
+  sif::printWarning("cfdp::DestHandler: parsing metadata PDU failed with code %04x\n", result);
 #endif
   PduHeaderReader headerReader(rawData, maxSize);
   result = headerReader.parseData();
@@ -307,24 +258,26 @@ ReturnValue_t cfdp::DestHandler::startTransaction(const MetadataPduReader& reade
   // so there is no need to create a file or truncate an existing file
   if (destNameSize > 0 and sourceNameSize > 0) {
     transactionParams.metadataOnly = false;
-    FilesystemParams fparams(transactionParams.destName.data());
     // handling to allow only specifying target directory. Example:
     // Source path /test/hello.txt, dest path /tmp -> dest path /tmp/hello.txt
-    if (destParams.user.vfs.isDirectory(transactionParams.destName.data())) {
+    bool isDirectory = false;
+
+    result = destParams.user.vfs.isDirectory(transactionParams.destName.data(), isDirectory);
+    if (result == returnvalue::OK && isDirectory) {
       result = tryBuildingAbsoluteDestName(destNameSize);
       if (result != OK) {
         return result;
       }
     }
-    if (destParams.user.vfs.fileExists(fparams)) {
+    if (destParams.user.vfs.fileExists(transactionParams.destName.data())) {
-      result = destParams.user.vfs.truncateFile(fparams);
+      result = destParams.user.vfs.truncateFile(transactionParams.destName.data());
       if (result != returnvalue::OK) {
         fileErrorHandler(events::FILESTORE_ERROR, result, "file truncation error");
         return FAILED;
         // TODO: Relevant for filestore rejection error?
       }
     } else {
-      result = destParams.user.vfs.createFile(fparams);
+      result = destParams.user.vfs.createFile(transactionParams.destName.data());
       if (result != OK) {
         fileErrorHandler(events::FILESTORE_ERROR, result, "file creation error");
         return FAILED;
@@ -359,6 +312,7 @@ ReturnValue_t cfdp::DestHandler::startTransaction(const MetadataPduReader& reade
   transactionParams.checksumType = info.getChecksumType();
   transactionParams.closureRequested = info.isClosureRequested();
   reader.fillConfig(transactionParams.pduConf);
+  transactionParams.pduConf.crcFlag = transactionParams.remoteCfg->crcOnTransmission;
   transactionParams.pduConf.direction = Direction::TOWARDS_SENDER;
   transactionParams.transactionId.entityId = transactionParams.pduConf.sourceId;
   transactionParams.transactionId.seqNum = transactionParams.pduConf.seqNum;
@@ -368,10 +322,10 @@ ReturnValue_t cfdp::DestHandler::startTransaction(const MetadataPduReader& reade
   params.destFileName = transactionParams.destName.data();
   params.sourceFileName = transactionParams.sourceName.data();
   params.numberOfMsgsToUser = 0;
-  for (const auto& opt : tlvVec) {
+  for (uint32_t tlvIdx = 0; tlvIdx < reader.getNumberOfParsedOptions(); tlvIdx++) {
-    if (opt.getType() == TlvType::MSG_TO_USER) {
+    if (tlvVec[tlvIdx].getType() == TlvType::MSG_TO_USER) {
       msgToUserVec[params.numberOfMsgsToUser] =
-          MessageToUserTlv(opt.getValue(), opt.getLengthField());
+          MessageToUserTlv(tlvVec[tlvIdx].getValue(), tlvVec[tlvIdx].getLengthField());
       params.numberOfMsgsToUser++;
     }
   }
@@ -411,10 +365,9 @@ ReturnValue_t cfdp::DestHandler::tryBuildingAbsoluteDestName(size_t destNameSize
   // A path may only have a maximum of 256 characters in CFDP, so this buffer should be sufficient
   // for all use-cases.
   char baseNameBuf[512]{};
-  FilesystemParams fparamsSrc(transactionParams.sourceName.data());
   size_t baseNameLen = 0;
-  ReturnValue_t result = destParams.user.vfs.getBaseFilename(fparamsSrc, baseNameBuf,
+  const ReturnValue_t result = destParams.user.vfs.getBaseFilename(
-                                                             sizeof(baseNameBuf), baseNameLen);
+      transactionParams.sourceName.data(), baseNameBuf, sizeof(baseNameBuf), baseNameLen);
   if (result != returnvalue::OK or baseNameLen == 0) {
     fileErrorHandler(events::FILENAME_TOO_LARGE_ERROR, 0, "error retrieving source base name");
     return FAILED;
@@ -442,7 +395,6 @@ void cfdp::DestHandler::fileErrorHandler(Event event, ReturnValue_t result,
 
 void cfdp::DestHandler::finish() {
   transactionParams.reset();
-  destParams.packetListRef.clear();
   fsmRes.state = CfdpState::IDLE;
   fsmRes.step = TransactionStep::IDLE;
 }
@@ -451,26 +403,26 @@ ReturnValue_t cfdp::DestHandler::checksumVerification() {
   std::array<uint8_t, 1024> buf{};
   etl::crc32 crcCalc;
   uint64_t currentOffset = 0;
-  FileOpParams params(transactionParams.destName.data(), transactionParams.fileSize.value());
   while (currentOffset < transactionParams.fileSize.value()) {
-    uint64_t readLen;
+    uint64_t lenToRead;
     if (currentOffset + buf.size() > transactionParams.fileSize.value()) {
-      readLen = transactionParams.fileSize.value() - currentOffset;
+      lenToRead = transactionParams.fileSize.value() - currentOffset;
     } else {
-      readLen = buf.size();
+      lenToRead = buf.size();
     }
-    if (readLen > 0) {
+    if (lenToRead > 0) {
-      params.offset = currentOffset;
+      size_t readLen = 0;
-      params.size = readLen;
+      const auto result =
-      auto result = destParams.user.vfs.readFromFile(params, buf.data(), buf.size());
+          destParams.user.vfs.readFromFile(transactionParams.destName.data(), currentOffset,
+                                           lenToRead, buf.data(), readLen, buf.size());
       if (result != OK) {
         // TODO: I think this is a case for a filestore rejection, but it might sense to print
         //       a warning or trigger an event because this should generally not happen
         return FAILED;
       }
-      crcCalc.add(buf.begin(), buf.begin() + readLen);
+      crcCalc.add(buf.begin(), buf.begin() + lenToRead);
     }
-    currentOffset += readLen;
+    currentOffset += lenToRead;
   }
 
   uint32_t value = crcCalc.value();
@@ -502,19 +454,11 @@ ReturnValue_t cfdp::DestHandler::sendFinishedPdu() {
   FinishedInfo info(transactionParams.conditionCode, transactionParams.deliveryCode,
                     transactionParams.deliveryStatus);
   FinishPduCreator finishedPdu(transactionParams.pduConf, info);
-  store_address_t storeId;
+
-  uint8_t* dataPtr = nullptr;
-  ReturnValue_t result =
-      fsfwParams.tmStore->getFreeElement(&storeId, finishedPdu.getSerializedSize(), &dataPtr);
-  if (result != OK) {
-#if FSFW_CPP_OSTREAM_ENABLED == 1
-    sif::warning << "cfdp::DestHandler:sendFinishedPdu: Getting store slot failed" << std::endl;
-#endif
-    fsfwParams.eventReporter->forwardEvent(events::STORE_ERROR, result, 0);
-    return result;
-  }
   size_t serLen = 0;
-  result = finishedPdu.serialize(dataPtr, serLen, finishedPdu.getSerializedSize());
+  ReturnValue_t result =
+      finishedPdu.serialize(pduBuf.data(), serLen, finishedPdu.getSerializedSize());
+  checkAndHandleError(result, fsmRes.errors);
   if (result != OK) {
 #if FSFW_CPP_OSTREAM_ENABLED == 1
     sif::warning << "cfdp::DestHandler::sendFinishedPdu: Serializing Finished PDU failed"
@@ -523,13 +467,12 @@ ReturnValue_t cfdp::DestHandler::sendFinishedPdu() {
     fsfwParams.eventReporter->forwardEvent(events::SERIALIZATION_ERROR, result, 0);
     return result;
   }
-  TmTcMessage msg(storeId);
+  pduSender.sendPdu(PduType::FILE_DIRECTIVE, FileDirective::FINISH, pduBuf.data(), serLen);
-  result = fsfwParams.msgQueue->sendMessage(fsfwParams.packetDest.getReportReceptionQueue(), &msg);
   if (result != OK) {
 #if FSFW_CPP_OSTREAM_ENABLED == 1
     sif::warning << "cfdp::DestHandler::sendFinishedPdu: Sending PDU failed" << std::endl;
 #endif
-    fsfwParams.eventReporter->forwardEvent(events::MSG_QUEUE_ERROR, result, 0);
+    fsfwParams.eventReporter->forwardEvent(events::PDU_SEND_ERROR, result, 0);
     return result;
   }
   fsmRes.packetsSent++;
@@ -560,8 +503,6 @@ void cfdp::DestHandler::checkAndHandleError(ReturnValue_t result, uint8_t& error
   }
 }
 
-void cfdp::DestHandler::setMsgQueue(MessageQueueIF& queue) { fsfwParams.msgQueue = &queue; }
-
 void cfdp::DestHandler::setEventReporter(EventReportingProxyIF& reporter) {
   fsfwParams.eventReporter = &reporter;
 }
@@ -569,6 +510,3 @@ void cfdp::DestHandler::setEventReporter(EventReportingProxyIF& reporter) {
 const cfdp::DestHandlerParams& cfdp::DestHandler::getDestHandlerParams() const {
   return destParams;
 }
-
-StorageManagerIF* cfdp::DestHandler::getTmStore() const { return fsfwParams.tmStore; }
-StorageManagerIF* cfdp::DestHandler::getTcStore() const { return fsfwParams.tcStore; }

src/fsfw/cfdp/handler/DestHandler.h

@@ -11,13 +11,13 @@
 #include "RemoteConfigTableIF.h"
 #include "UserBase.h"
 #include "defs.h"
+#include "fsfw/cfdp/handler/PduPacketIF.h"
+#include "fsfw/cfdp/handler/PduSenderIF.h"
 #include "fsfw/cfdp/handler/mib.h"
 #include "fsfw/cfdp/pdu/MetadataPduReader.h"
 #include "fsfw/cfdp/pdu/PduConfig.h"
 #include "fsfw/cfdp/tlv/MessageToUserTlv.h"
-#include "fsfw/container/DynamicFIFO.h"
 #include "fsfw/storagemanager/StorageManagerIF.h"
-#include "fsfw/storagemanager/storeAddress.h"
 #include "fsfw/tmtcservices/AcceptsTelemetryIF.h"
 
 namespace cfdp {
@@ -28,7 +28,6 @@ using LostSegmentsListBase = etl::iset<etl::pair<uint64_t, uint64_t>>;
 
 struct DestHandlerParams {
   DestHandlerParams(LocalEntityCfg cfg, UserBase& user, RemoteConfigTableIF& remoteCfgTable,
-                    PacketInfoListBase& packetList,
                     //  TODO: This container can potentially take tons of space. For a better
                     //        memory efficient implementation, an additional abstraction could be
                     //        be used so users can use uint32_t as the pair type
@@ -39,14 +38,12 @@ struct DestHandlerParams {
       : cfg(std::move(cfg)),
         user(user),
         remoteCfgTable(remoteCfgTable),
-        packetListRef(packetList),
         lostSegmentsContainer(lostSegmentsContainer) {}
 
   LocalEntityCfg cfg;
   UserBase& user;
   RemoteConfigTableIF& remoteCfgTable;
 
-  PacketInfoListBase& packetListRef;
   LostSegmentsListBase& lostSegmentsContainer;
   uint8_t maxTlvsInOnePdu = 20;
   size_t maxFilenameLen = 255;
@@ -64,17 +61,14 @@ class DestHandler {
   };
 
   struct FsmResult {
-   public:
+    uint32_t packetsSent = 0;
     ReturnValue_t result = returnvalue::OK;
-    CallStatus callStatus = CallStatus::CALL_AFTER_DELAY;
     TransactionStep step = TransactionStep::IDLE;
     CfdpState state = CfdpState::IDLE;
-    uint32_t packetsSent = 0;
     uint8_t errors = 0;
     std::array<ReturnValue_t, 3> errorCodes = {};
     void resetOfIteration() {
       result = returnvalue::OK;
-      callStatus = CallStatus::CALL_AFTER_DELAY;
       packetsSent = 0;
       errors = 0;
       errorCodes.fill(returnvalue::OK);
@@ -85,28 +79,30 @@ class DestHandler {
    */
   ReturnValue_t PARTIAL_SUCCESS = returnvalue::makeCode(0, 2);
   ReturnValue_t FAILURE = returnvalue::makeCode(0, 3);
-  explicit DestHandler(DestHandlerParams handlerParams, FsfwParams fsfwParams);
+
+  explicit DestHandler(PduSenderIF& pduSender, size_t pduBufSize, DestHandlerParams handlerParams,
+                       FsfwParams fsfwParams);
 
   /**
+   * This is the core function to drive the destination handler. It is also used to insert
+   * packets into the destination handler.
    *
-   * @return
+   * The state machine should either be called if packets with the appropriate destination ID
-   *  - @c returnvalue::OK  State machine OK for this execution cycle
+   * are received and periodically to perform all CFDP related tasks, for example
-   *  - @c CALL_FSM_AGAIN   State machine should be called again.
+   * checking for timeouts or missed file segments.
+   *
+   * The function returns the number of sent PDU packets on success.
    */
-  const FsmResult& stateMachine();
+  const FsmResult& stateMachine(std::optional<std::reference_wrapper<PduPacketIF>> optPduPacket);
-  void setMsgQueue(MessageQueueIF& queue);
+
+  const FsmResult& stateMachineNoPacket();
+
   void setEventReporter(EventReportingProxyIF& reporter);
 
-  ReturnValue_t passPacket(PacketInfo packet);
-
-  ReturnValue_t initialize();
-
   [[nodiscard]] CfdpState getCfdpState() const;
   [[nodiscard]] TransactionStep getTransactionStep() const;
   [[nodiscard]] const TransactionId& getTransactionId() const;
   [[nodiscard]] const DestHandlerParams& getDestHandlerParams() const;
-  [[nodiscard]] StorageManagerIF* getTcStore() const;
-  [[nodiscard]] StorageManagerIF* getTmStore() const;
 
  private:
   struct TransactionParams {
@@ -149,6 +145,8 @@ class DestHandler {
     RemoteEntityCfg* remoteCfg = nullptr;
   };
 
+  std::vector<uint8_t> pduBuf;
+  PduSenderIF& pduSender;
   std::vector<cfdp::Tlv> tlvVec;
   std::vector<MessageToUserTlv> msgToUserVec;
   TransactionParams transactionParams;
@@ -157,9 +155,9 @@ class DestHandler {
   FsmResult fsmRes;
 
   ReturnValue_t startTransaction(const MetadataPduReader& reader);
-  ReturnValue_t handleMetadataPdu(const PacketInfo& info);
+  ReturnValue_t handleMetadataPdu(const PduPacketIF& pduPacket);
-  ReturnValue_t handleFileDataPdu(const PacketInfo& info);
+  ReturnValue_t handleFileDataPdu(const PduPacketIF& info);
-  ReturnValue_t handleEofPdu(const PacketInfo& info);
+  ReturnValue_t handleEofPdu(const PduPacketIF& info);
   ReturnValue_t handleMetadataParseError(ReturnValue_t result, const uint8_t* rawData,
                                          size_t maxSize);
   ReturnValue_t handleTransferCompletion();

src/fsfw/cfdp/handler/PduPacketIF.h

@@ -0,0 +1,18 @@
+#pragma once
+
+#include <optional>
+
+#include "fsfw/cfdp/definitions.h"
+
+namespace cfdp {
+
+class PduPacketIF {
+ public:
+  virtual ~PduPacketIF() = default;
+
+  [[nodiscard]] virtual cfdp::PduType getPduType() const = 0;
+  [[nodiscard]] virtual std::optional<cfdp::FileDirective> getFileDirective() const = 0;
+  [[nodiscard]] virtual const uint8_t* getRawPduData(size_t& pduLen) const = 0;
+};
+
+}  // namespace cfdp

src/fsfw/cfdp/handler/PduSenderIF.h

@@ -0,0 +1,17 @@
+#pragma once
+
+#include <optional>
+
+#include "fsfw/cfdp/definitions.h"
+
+namespace cfdp {
+class PduSenderIF {
+ public:
+  virtual ~PduSenderIF() = default;
+
+  virtual ReturnValue_t sendPdu(cfdp::PduType pduType,
+                                std::optional<cfdp::FileDirective> fileDirective,
+                                const uint8_t* pdu, size_t pduSize) = 0;
+};
+
+}  // namespace cfdp

src/fsfw/cfdp/handler/ReservedMessageParser.cpp

@@ -14,7 +14,7 @@ cfdp::ReservedMessageParser::ReservedMessageParser(StorageManagerIF& ipcStore,
     : msgQueue(msgQueue), ipcStore(ipcStore), userDestination(userDestination) {}
 
 ReturnValue_t cfdp::ReservedMessageParser::parse(const MessageToUserTlv* msgsToUserArray,
-                                                 size_t numMsgToUser) {
+                                                 size_t numMsgToUser) const {
   ReturnValue_t result = returnvalue::OK;
   cfdp::StringLv sourceFileName;
   cfdp::StringLv destFileName;
@@ -23,11 +23,10 @@ ReturnValue_t cfdp::ReservedMessageParser::parse(const MessageToUserTlv* msgsToU
   size_t deserSize = 0;
   bool needToSendPutRequest = false;
   for (size_t idx = 0; idx < numMsgToUser; idx++) {
-    if (&msgsToUserArray[idx] == nullptr) {
+    uint8_t messageType = 0;
+    if (not msgsToUserArray[idx].isReservedCfdpMessage(messageType, &currentPtr, deserSize)) {
       continue;
     }
-    uint8_t messageType = 0;
-    if (msgsToUserArray[idx].isReservedCfdpMessage(messageType, &currentPtr, deserSize)) {
     if (messageType == static_cast<uint8_t>(ProxyOpMessageType::PUT_REQUEST)) {
       EntityId entityIdLv;
       result = entityIdLv.deSerializeFromLv(&currentPtr, &deserSize);
@@ -40,8 +39,7 @@ ReturnValue_t cfdp::ReservedMessageParser::parse(const MessageToUserTlv* msgsToU
       if (result != OK) {
         return result;
       }
-        result =
+      result = destFileName.deSerialize(&currentPtr, &deserSize, SerializeIF::Endianness::NETWORK);
-            destFileName.deSerialize(&currentPtr, &deserSize, SerializeIF::Endianness::NETWORK);
       if (result != OK) {
         return result;
       }
@@ -49,7 +47,6 @@ ReturnValue_t cfdp::ReservedMessageParser::parse(const MessageToUserTlv* msgsToU
       needToSendPutRequest = true;
     }
   }
-  }
   if (needToSendPutRequest) {
     store_address_t storeId;
     uint8_t* dataPtr;

src/fsfw/cfdp/handler/ReservedMessageParser.h

@@ -16,7 +16,7 @@ class ReservedMessageParser {
   ReservedMessageParser(StorageManagerIF& ipcStore, MessageQueueIF& msgQueue,
                         MessageQueueId_t userDestination);
 
-  ReturnValue_t parse(const MessageToUserTlv* msgsToUserArray, size_t numMsgsToUser);
+  ReturnValue_t parse(const MessageToUserTlv* msgsToUserArray, size_t numMsgsToUser) const;
 
  private:
   MessageQueueIF& msgQueue;

src/fsfw/cfdp/handler/SourceHandler.cpp

@@ -16,8 +16,12 @@
 
 using namespace returnvalue;
 
-cfdp::SourceHandler::SourceHandler(SourceHandlerParams params, FsfwParams fsfwParams)
+cfdp::SourceHandler::SourceHandler(PduSenderIF& pduSender, size_t pduBufferSize,
-    : sourceParams(std::move(params)), fsfwParams(fsfwParams) {
+                                   SourceHandlerParams params, FsfwParams fsfwParams)
+    : pduSender(pduSender),
+      pduBuf(pduBufferSize),
+      sourceParams(std::move(params)),
+      fsfwParams(fsfwParams) {
   // The entity ID portion of the transaction ID will always remain fixed.
   transactionParams.id.entityId = sourceParams.cfg.localId;
   transactionParams.pduConf.sourceId = sourceParams.cfg.localId;
@@ -61,14 +65,14 @@ cfdp::SourceHandler::FsmResult& cfdp::SourceHandler::fsmNacked() {
     if (result != OK) {
       addError(result);
     }
-    fsmResult.callStatus = CallStatus::CALL_AGAIN;
+    // fsmResult.callStatus = CallStatus::CALL_AGAIN;
     return fsmResult;
   }
   if (step == TransactionStep::SENDING_FILE_DATA) {
     bool noFdPdu = false;
     result = prepareAndSendNextFileDataPdu(noFdPdu);
     if (result == OK and !noFdPdu) {
-      fsmResult.callStatus = CallStatus::CALL_AGAIN;
+      // fsmResult.callStatus = CallStatus::CALL_AGAIN;
       return fsmResult;
     }
   }
@@ -82,10 +86,10 @@ cfdp::SourceHandler::FsmResult& cfdp::SourceHandler::fsmNacked() {
     }
     if (transactionParams.closureRequested) {
       step = TransactionStep::WAIT_FOR_FINISH;
-      fsmResult.callStatus = CallStatus::CALL_AFTER_DELAY;
+      // fsmResult.callStatus = CallStatus::CALL_AFTER_DELAY;
     } else {
       step = TransactionStep::NOTICE_OF_COMPLETION;
-      fsmResult.callStatus = CallStatus::CALL_AGAIN;
+      // fsmResult.callStatus = CallStatus::CALL_AGAIN;
     }
     return fsmResult;
   }
@@ -101,10 +105,14 @@ cfdp::SourceHandler::FsmResult& cfdp::SourceHandler::fsmNacked() {
   return fsmResult;
 }
 
-const cfdp::SourceHandler::FsmResult& cfdp::SourceHandler::stateMachine() {
+const cfdp::SourceHandler::FsmResult& cfdp::SourceHandler::stateMachineNoPacket() {
+  return stateMachine(std::nullopt);
+}
+
+const cfdp::SourceHandler::FsmResult& cfdp::SourceHandler::stateMachine(
+    std::optional<std::reference_wrapper<PduPacketIF>> optPduPacket) {
   fsmResult.packetsSent = 0;
   fsmResult.errors = 0;
-  fsmResult.callStatus = CallStatus::DONE;
   if (state == cfdp::CfdpState::IDLE) {
     return fsmResult;
   }
@@ -123,25 +131,25 @@ ReturnValue_t cfdp::SourceHandler::checksumGeneration() {
   std::array<uint8_t, 1024> buf{};
   etl::crc32 crcCalc;
   uint64_t currentOffset = 0;
-  FileOpParams params(transactionParams.sourceName.data(), transactionParams.fileSize.value());
   while (currentOffset < transactionParams.fileSize.value()) {
-    uint64_t readLen;
+    uint64_t lenToRead;
     if (currentOffset + buf.size() > transactionParams.fileSize.value()) {
-      readLen = transactionParams.fileSize.value() - currentOffset;
+      lenToRead = transactionParams.fileSize.value() - currentOffset;
     } else {
-      readLen = buf.size();
+      lenToRead = buf.size();
     }
-    if (readLen > 0) {
+    if (lenToRead > 0) {
-      params.offset = currentOffset;
+      size_t readLen = 0;
-      params.size = readLen;
+      auto result =
-      auto result = sourceParams.user.vfs.readFromFile(params, buf.data(), buf.size());
+          sourceParams.user.vfs.readFromFile(transactionParams.sourceName.data(), currentOffset,
+                                             lenToRead, buf.data(), readLen, buf.size());
       if (result != OK) {
         addError(result);
         return FAILED;
       }
-      crcCalc.add(buf.begin(), buf.begin() + readLen);
+      crcCalc.add(buf.begin(), buf.begin() + lenToRead);
     }
-    currentOffset += readLen;
+    currentOffset += lenToRead;
   }
 
   transactionParams.crc = crcCalc.value();
@@ -169,8 +177,7 @@ ReturnValue_t cfdp::SourceHandler::transactionStart(PutRequest& putRequest, Remo
   // operation is safe.
   transactionParams.sourceName[transactionParams.sourceNameSize] = '\0';
   transactionParams.destName[transactionParams.destNameSize] = '\0';
-  FilesystemParams params(transactionParams.sourceName.data());
+  if (!sourceParams.user.vfs.fileExists(transactionParams.sourceName.data())) {
-  if (!sourceParams.user.vfs.fileExists(params)) {
     return FILE_DOES_NOT_EXIST;
   }
   if (cfg.maxFileSegmentLen > fileBuf.size() or cfg.maxFileSegmentLen == 0) {
@@ -206,7 +213,7 @@ ReturnValue_t cfdp::SourceHandler::transactionStart(PutRequest& putRequest, Remo
   }
   step = TransactionStep::IDLE;
   uint64_t fileSize = 0;
-  sourceParams.user.vfs.getFileSize(params, fileSize);
+  sourceParams.user.vfs.getFileSize(transactionParams.sourceName.data(), fileSize);
   transactionParams.pduConf.largeFile = false;
   if (fileSize > UINT32_MAX) {
     transactionParams.pduConf.largeFile = true;
@@ -230,7 +237,8 @@ ReturnValue_t cfdp::SourceHandler::prepareAndSendMetadataPdu() {
                           transactionParams.fileSize);
   auto metadataPdu =
       MetadataPduCreator(transactionParams.pduConf, metadataInfo, sourceName, destName, nullptr, 0);
-  ReturnValue_t result = sendGenericPdu(metadataPdu);
+  ReturnValue_t result =
+      sendGenericPdu(PduType::FILE_DIRECTIVE, FileDirective::METADATA, metadataPdu);
   if (result != OK) {
     return result;
   }
@@ -241,7 +249,7 @@ ReturnValue_t cfdp::SourceHandler::prepareAndSendMetadataPdu() {
 
 ReturnValue_t cfdp::SourceHandler::prepareAndSendNextFileDataPdu(bool& noFileDataPdu) {
   cfdp::Fss offset(transactionParams.progress);
-  uint64_t readLen;
+  uint64_t lenToRead;
   uint64_t fileSize = transactionParams.fileSize.value();
   noFileDataPdu = false;
   if (fileSize == 0) {
@@ -251,29 +259,31 @@ ReturnValue_t cfdp::SourceHandler::prepareAndSendNextFileDataPdu(bool& noFileDat
     return OK;
   }
   if (fileSize < transactionParams.remoteCfg.maxFileSegmentLen) {
-    readLen = transactionParams.fileSize.value();
+    lenToRead = transactionParams.fileSize.value();
   } else {
     if (transactionParams.progress + transactionParams.remoteCfg.maxFileSegmentLen > fileSize) {
-      readLen = fileSize - transactionParams.progress;
+      lenToRead = fileSize - transactionParams.progress;
     } else {
-      readLen = transactionParams.remoteCfg.maxFileSegmentLen;
+      lenToRead = transactionParams.remoteCfg.maxFileSegmentLen;
     }
   }
-  FileOpParams fileParams(transactionParams.sourceName.data(), readLen);
+  FileOpParams fileParams(transactionParams.sourceName.data(), lenToRead);
   fileParams.offset = transactionParams.progress;
-  ReturnValue_t result =
+  size_t readLen = 0;
-      sourceParams.user.vfs.readFromFile(fileParams, fileBuf.data(), fileBuf.size());
+  ReturnValue_t result = sourceParams.user.vfs.readFromFile(
+      transactionParams.sourceName.data(), transactionParams.progress, lenToRead, fileBuf.data(),
+      readLen, fileBuf.size());
   if (result != returnvalue::OK) {
     addError(result);
     return result;
   }
-  auto fileDataInfo = FileDataInfo(offset, fileBuf.data(), readLen);
+  auto fileDataInfo = FileDataInfo(offset, fileBuf.data(), lenToRead);
   auto fileDataPdu = FileDataCreator(transactionParams.pduConf, fileDataInfo);
-  result = sendGenericPdu(fileDataPdu);
+  result = sendGenericPdu(PduType::FILE_DATA, std::nullopt, fileDataPdu);
   if (result != OK) {
     return result;
   }
-  transactionParams.progress += readLen;
+  transactionParams.progress += lenToRead;
   if (transactionParams.progress >= fileSize) {
     // Advance FSM after all file data PDUs were sent.
     step = TransactionStep::SENDING_EOF;
@@ -285,72 +295,44 @@ ReturnValue_t cfdp::SourceHandler::prepareAndSendEofPdu() {
   auto eofInfo =
       EofInfo(ConditionCode::NO_ERROR, transactionParams.crc, transactionParams.fileSize);
   auto eofPdu = EofPduCreator(transactionParams.pduConf, eofInfo);
-  ReturnValue_t result = sendGenericPdu(eofPdu);
-  if (result != OK) {
-    return result;
-  }
-  return OK;
-}
-
-ReturnValue_t cfdp::SourceHandler::initialize() {
-  if (fsfwParams.tmStore == nullptr) {
-    fsfwParams.tmStore = ObjectManager::instance()->get<StorageManagerIF>(objects::TM_STORE);
-    if (fsfwParams.tmStore == nullptr) {
-      return FAILED;
-    }
-  }
-
-  if (fsfwParams.tcStore == nullptr) {
-    fsfwParams.tcStore = ObjectManager::instance()->get<StorageManagerIF>(objects::TC_STORE);
-    if (fsfwParams.tcStore == nullptr) {
-      return FAILED;
-    }
-  }
-
-  if (fsfwParams.msgQueue == nullptr) {
-    return FAILED;
-  }
-  return OK;
-}
-
-ReturnValue_t cfdp::SourceHandler::sendGenericPdu(const SerializeIF& pdu) {
-  uint8_t* dataPtr;
-  store_address_t storeId;
   ReturnValue_t result =
-      fsfwParams.tmStore->getFreeElement(&storeId, pdu.getSerializedSize(), &dataPtr);
+      sendGenericPdu(PduType::FILE_DIRECTIVE, FileDirective::EOF_DIRECTIVE, eofPdu);
   if (result != OK) {
-    addError(result);
-    fsmResult.callStatus = CallStatus::CALL_AFTER_DELAY;
-    if (result == StorageManagerIF::DATA_STORAGE_FULL) {
-      return TM_STORE_FULL;
-    }
     return result;
   }
+  return OK;
+}
+
+ReturnValue_t cfdp::SourceHandler::initialize() { return OK; }
+
+ReturnValue_t cfdp::SourceHandler::sendGenericPdu(PduType pduType,
+                                                  std::optional<FileDirective> fileDirective,
+                                                  const SerializeIF& pdu) {
+  store_address_t storeId;
+  if (pdu.getSerializedSize() > pduBuf.size()) {
+    addError(PDU_BUFFER_TOO_SMALL);
+    return PDU_BUFFER_TOO_SMALL;
+  }
   size_t serializedLen = 0;
-  result = pdu.serializeBe(dataPtr, serializedLen, pdu.getSerializedSize());
+  ReturnValue_t result = pdu.serializeBe(pduBuf.data(), serializedLen, pdu.getSerializedSize());
   if (result != OK) {
     addError(result);
     return result;
   }
-  TmTcMessage tmMsg(storeId);
+  pduSender.sendPdu(pduType, fileDirective, pduBuf.data(), serializedLen);
-  result =
-      fsfwParams.msgQueue->sendMessage(fsfwParams.packetDest.getReportReceptionQueue(), &tmMsg);
-  if (result != OK) {
-    fsmResult.callStatus = CallStatus::CALL_AFTER_DELAY;
-  }
-  if (result == MessageQueueIF::FULL) {
-    return TARGET_MSG_QUEUE_FULL;
-  } else if (result == OK) {
   fsmResult.packetsSent += 1;
-  }
   return result;
 }
 
 ReturnValue_t cfdp::SourceHandler::noticeOfCompletion() {
   if (sourceParams.cfg.indicCfg.transactionFinishedIndicRequired) {
+    // TODO: This could still be improved by caching the Finished PDU parameters.
+    FileDeliveryStatus deliveryStatus = FileDeliveryStatus::FILE_STATUS_UNREPORTED;
+    if (transactionParams.closureRequested) {
+      deliveryStatus = FileDeliveryStatus::RETAINED_IN_FILESTORE;
+    }
     cfdp::TransactionFinishedParams params(transactionParams.id, ConditionCode::NO_ERROR,
-                                           FileDeliveryCode::DATA_COMPLETE,
+                                           FileDeliveryCode::DATA_COMPLETE, deliveryStatus);
-                                           FileDeliveryStatus::RETAINED_IN_FILESTORE);
     sourceParams.user.transactionFinishedIndication(params);
   }
   return OK;
@@ -359,7 +341,7 @@ ReturnValue_t cfdp::SourceHandler::noticeOfCompletion() {
 ReturnValue_t cfdp::SourceHandler::reset() {
   step = TransactionStep::IDLE;
   state = cfdp::CfdpState::IDLE;
-  fsmResult.callStatus = CallStatus::DONE;
+  // fsmResult.callStatus = CallStatus::DONE;
   transactionParams.reset();
   return OK;
 }

src/fsfw/cfdp/handler/SourceHandler.h

@@ -4,6 +4,8 @@
 #include <cstdint>
 #include <vector>
 
+#include "PduPacketIF.h"
+#include "PduSenderIF.h"
 #include "UserBase.h"
 #include "defs.h"
 #include "fsfw/cfdp/Fss.h"
@@ -40,14 +42,15 @@ class SourceHandler {
   struct FsmResult {
    public:
     ReturnValue_t result = returnvalue::OK;
-    CallStatus callStatus = CallStatus::CALL_AFTER_DELAY;
-    CfdpState state = CfdpState::IDLE;
     uint32_t packetsSent = 0;
+    // CallStatus callStatus = CallStatus::CALL_AFTER_DELAY;
+    CfdpState state = CfdpState::IDLE;
     uint8_t errors = 0;
     std::array<ReturnValue_t, 3> errorCodes = {};
   };
 
-  SourceHandler(SourceHandlerParams params, FsfwParams fsfwParams);
+  SourceHandler(PduSenderIF& pduSender, size_t pduBufferSize, SourceHandlerParams params,
+                FsfwParams fsfwParams);
 
   [[nodiscard]] CfdpState getState() const;
   [[nodiscard]] TransactionStep getStep() const;
@@ -58,7 +61,8 @@ class SourceHandler {
    * @return
    */
   ReturnValue_t transactionStart(PutRequest& putRequest, RemoteEntityCfg& cfg);
-  const FsmResult& stateMachine();
+  const FsmResult& stateMachine(std::optional<std::reference_wrapper<PduPacketIF>> optPduPacket);
+  const FsmResult& stateMachineNoPacket();
 
   ReturnValue_t initialize();
 
@@ -86,6 +90,8 @@ class SourceHandler {
     }
   } transactionParams;
 
+  PduSenderIF& pduSender;
+  std::vector<uint8_t> pduBuf;
   cfdp::CfdpState state = cfdp::CfdpState::IDLE;
   TransactionStep step = TransactionStep::IDLE;
   std::array<uint8_t, 4096> fileBuf{};
@@ -101,7 +107,9 @@ class SourceHandler {
   ReturnValue_t noticeOfCompletion();
   ReturnValue_t reset();
 
-  [[nodiscard]] ReturnValue_t sendGenericPdu(const SerializeIF& pdu);
+  [[nodiscard]] ReturnValue_t sendGenericPdu(PduType pduType,
+                                             std::optional<FileDirective> fileDirective,
+                                             const SerializeIF& pdu);
   void addError(ReturnValue_t error);
 };
 

src/fsfw/cfdp/handler/defs.h

@@ -1,5 +1,4 @@
-#ifndef FSFW_CFDP_HANDLER_DEFS_H
+#pragma once
-#define FSFW_CFDP_HANDLER_DEFS_H
 
 #include <etl/list.h>
 
@@ -8,59 +7,25 @@
 #include "fsfw/tmtcservices/AcceptsTelemetryIF.h"
 
 namespace cfdp {
-
 enum class CfdpState { IDLE, BUSY_CLASS_1_NACKED, BUSY_CLASS_2_ACKED, SUSPENDED };
 
 static constexpr uint8_t SSID = SUBSYSTEM_ID::CFDP;
 static constexpr uint8_t CID = CLASS_ID::CFDP_HANDLER;
 
-struct PacketInfo {
-  PacketInfo(PduType type, store_address_t storeId,
-             std::optional<FileDirective> directive = std::nullopt)
-      : pduType(type), directiveType(directive), storeId(storeId) {}
-
-  PduType pduType = PduType::FILE_DATA;
-  std::optional<FileDirective> directiveType = FileDirective::INVALID_DIRECTIVE;
-  store_address_t storeId = store_address_t::invalid();
-  PacketInfo() = default;
-};
-
 struct FsfwParams {
-  FsfwParams(AcceptsTelemetryIF& packetDest, MessageQueueIF* msgQueue,
+  FsfwParams(EventReportingProxyIF* eventReporter) : eventReporter(eventReporter) {}
-             EventReportingProxyIF* eventReporter, StorageManagerIF& tcStore,
-             StorageManagerIF& tmStore)
-      : FsfwParams(packetDest, msgQueue, eventReporter) {
-    this->tcStore = &tcStore;
-    this->tmStore = &tmStore;
-  }
 
-  FsfwParams(AcceptsTelemetryIF& packetDest, MessageQueueIF* msgQueue,
-             EventReportingProxyIF* eventReporter)
-      : packetDest(packetDest), msgQueue(msgQueue), eventReporter(eventReporter) {}
-  AcceptsTelemetryIF& packetDest;
-  MessageQueueIF* msgQueue;
   EventReportingProxyIF* eventReporter = nullptr;
-  StorageManagerIF* tcStore = nullptr;
-  StorageManagerIF* tmStore = nullptr;
 };
 
-template <size_t SIZE>
-using PacketInfoList = etl::list<PacketInfo, SIZE>;
-using PacketInfoListBase = etl::ilist<PacketInfo>;
-
-enum class CallStatus { DONE, CALL_AFTER_DELAY, CALL_AGAIN };
-
 namespace events {
-
+static constexpr Event PDU_SEND_ERROR = event::makeEvent(SSID, 1, severity::LOW);
-static constexpr Event STORE_ERROR = event::makeEvent(SSID, 0, severity::LOW);
-static constexpr Event MSG_QUEUE_ERROR = event::makeEvent(SSID, 1, severity::LOW);
 static constexpr Event SERIALIZATION_ERROR = event::makeEvent(SSID, 2, severity::LOW);
 static constexpr Event FILESTORE_ERROR = event::makeEvent(SSID, 3, severity::LOW);
 //! [EXPORT] : [COMMENT] P1: Transaction step ID, P2: 0 for source file name, 1 for dest file name
 static constexpr Event FILENAME_TOO_LARGE_ERROR = event::makeEvent(SSID, 4, severity::LOW);
 //! [EXPORT] : [COMMENT] CFDP request handling failed. P2: Returncode.
 static constexpr Event HANDLING_CFDP_REQUEST_FAILED = event::makeEvent(SSID, 5, severity::LOW);
-
 }  // namespace events
 
 static constexpr ReturnValue_t SOURCE_TRANSACTION_PENDING = returnvalue::makeCode(CID, 0);
@@ -71,6 +36,6 @@ static constexpr ReturnValue_t DEST_NAME_EMPTY = returnvalue::makeCode(CID, 4);
 static constexpr ReturnValue_t WRONG_REMOTE_CFG_ENTITY_ID = returnvalue::makeCode(CID, 5);
 static constexpr ReturnValue_t TARGET_MSG_QUEUE_FULL = returnvalue::makeCode(CID, 6);
 static constexpr ReturnValue_t TM_STORE_FULL = returnvalue::makeCode(CID, 7);
-
+static constexpr ReturnValue_t DEST_NON_METADATA_PDU_AS_FIRST_PDU = returnvalue::makeCode(CID, 8);
+static constexpr ReturnValue_t PDU_BUFFER_TOO_SMALL = returnvalue::makeCode(CID, 9);
 }  // namespace cfdp
-#endif  // FSFW_CFDP_HANDLER_DEFS_H

src/fsfw/cfdp/pdu/AckPduCreator.cpp

@@ -1,5 +1,7 @@
 #include "AckPduCreator.h"
 
+#include "fsfw/globalfunctions/CRC.h"
+
 AckPduCreator::AckPduCreator(AckInfo &ackInfo, PduConfig &pduConf)
     : FileDirectiveCreator(pduConf, cfdp::FileDirective::ACK, 2), ackInfo(ackInfo) {}
 
@@ -7,6 +9,7 @@ size_t AckPduCreator::getSerializedSize() const { return FileDirectiveCreator::g
 
 ReturnValue_t AckPduCreator::serialize(uint8_t **buffer, size_t *size, size_t maxSize,
                                        Endianness streamEndianness) const {
+  const uint8_t *start = *buffer;
   ReturnValue_t result = FileDirectiveCreator::serialize(buffer, size, maxSize, streamEndianness);
   if (result != returnvalue::OK) {
     return result;
@@ -29,5 +32,10 @@ ReturnValue_t AckPduCreator::serialize(uint8_t **buffer, size_t *size, size_t ma
   **buffer = ackedConditionCode << 4 | transactionStatus;
   *buffer += 1;
   *size += 1;
+
+  if (getCrcFlag()) {
+    uint16_t crc = CRC::crc16ccitt(start, getWholePduSize() - 2);
+    result = SerializeAdapter::serialize(&crc, buffer, size, maxSize, streamEndianness);
+  }
   return returnvalue::OK;
 }

src/fsfw/cfdp/pdu/EofPduCreator.cpp

@@ -1,6 +1,7 @@
 #include "EofPduCreator.h"
 
 #include "fsfw/FSFW.h"
+#include "fsfw/globalfunctions/CRC.h"
 
 EofPduCreator::EofPduCreator(PduConfig &conf, EofInfo &info)
     : FileDirectiveCreator(conf, cfdp::FileDirective::EOF_DIRECTIVE, 9), info(info) {
@@ -11,6 +12,7 @@ size_t EofPduCreator::getSerializedSize() const { return FileDirectiveCreator::g
 
 ReturnValue_t EofPduCreator::serialize(uint8_t **buffer, size_t *size, size_t maxSize,
                                        Endianness streamEndianness) const {
+  const uint8_t *start = *buffer;
   ReturnValue_t result = FileDirectiveCreator::serialize(buffer, size, maxSize, streamEndianness);
   if (result != returnvalue::OK) {
     return result;
@@ -36,5 +38,9 @@ ReturnValue_t EofPduCreator::serialize(uint8_t **buffer, size_t *size, size_t ma
   if (info.getFaultLoc() != nullptr and info.getConditionCode() != cfdp::ConditionCode::NO_ERROR) {
     result = info.getFaultLoc()->serialize(buffer, size, maxSize, streamEndianness);
   }
+  if (getCrcFlag()) {
+    uint16_t crc = CRC::crc16ccitt(start, getWholePduSize() - 2);
+    result = SerializeAdapter::serialize(&crc, buffer, size, maxSize, streamEndianness);
+  }
   return result;
 }

src/fsfw/cfdp/pdu/FileDataCreator.cpp

@@ -2,6 +2,8 @@
 
 #include <cstring>
 
+#include "fsfw/globalfunctions/CRC.h"
+
 FileDataCreator::FileDataCreator(PduConfig& conf, FileDataInfo& info)
     : HeaderCreator(conf, cfdp::PduType::FILE_DATA, 0, info.getSegmentMetadataFlag()), info(info) {
   update();
@@ -18,6 +20,7 @@ ReturnValue_t FileDataCreator::serialize(uint8_t** buffer, size_t* size, size_t
   if (buffer == nullptr or size == nullptr) {
     return returnvalue::FAILED;
   }
+  const uint8_t* start = *buffer;
   if (*size + getSerializedSize() > maxSize) {
     return SerializeIF::BUFFER_TOO_SHORT;
   }
@@ -50,6 +53,11 @@ ReturnValue_t FileDataCreator::serialize(uint8_t** buffer, size_t* size, size_t
   std::memcpy(*buffer, readOnlyPtr, fileSize);
   *buffer += fileSize;
   *size += fileSize;
+
+  if (getCrcFlag()) {
+    uint16_t crc = CRC::crc16ccitt(start, getWholePduSize() - 2);
+    result = SerializeAdapter::serialize(&crc, buffer, size, maxSize, streamEndianness);
+  }
   return returnvalue::OK;
 }
 

src/fsfw/cfdp/pdu/FileDataReader.cpp

@@ -8,6 +8,9 @@ ReturnValue_t FileDataReader::parseData() {
   if (result != returnvalue::OK) {
     return result;
   }
+  if (not performCrcCheckIfApplicable()) {
+    return cfdp::PDU_CHECKSUM_FAILURE;
+  }
   size_t currentIdx = PduHeaderReader::getHeaderSize();
   const uint8_t* buf = pointers.rawPtr + currentIdx;
   size_t remSize = PduHeaderReader::getWholePduSize() - currentIdx;
@@ -34,6 +37,9 @@ ReturnValue_t FileDataReader::parseData() {
   if (result != returnvalue::OK) {
     return result;
   }
+  if (getCrcFlag()) {
+    remSize -= 2;
+  }
   if (remSize > 0) {
     info.setFileData(buf, remSize);
   }

src/fsfw/cfdp/pdu/FileDataReader.h

@@ -3,7 +3,7 @@
 
 #include "../definitions.h"
 #include "FileDataInfo.h"
-#include "PduHeaderReader.h"
+#include "HeaderReader.h"
 
 class FileDataReader : public PduHeaderReader {
  public:

src/fsfw/cfdp/pdu/FileDirectiveReader.cpp

@@ -1,5 +1,7 @@
 #include "FileDirectiveReader.h"
 
+#include "fsfw/globalfunctions/CRC.h"
+
 FileDirectiveReader::FileDirectiveReader(const uint8_t *pduBuf, size_t maxSize)
     : PduHeaderReader(pduBuf, maxSize) {}
 
@@ -10,6 +12,10 @@ ReturnValue_t FileDirectiveReader::parseData() {
   if (result != returnvalue::OK) {
     return result;
   }
+  if (not performCrcCheckIfApplicable()) {
+    return cfdp::PDU_CHECKSUM_FAILURE;
+  }
+
   if (this->getPduDataFieldLen() < 1) {
     return cfdp::INVALID_PDU_DATAFIELD_LEN;
   }

src/fsfw/cfdp/pdu/FileDirectiveReader.h

@@ -2,7 +2,7 @@
 #define FSFW_SRC_FSFW_CFDP_PDU_FILEDIRECTIVEDESERIALIZER_H_
 
 #include "../definitions.h"
-#include "fsfw/cfdp/pdu/PduHeaderReader.h"
+#include "fsfw/cfdp/pdu/HeaderReader.h"
 
 /**
  * @brief   This class is used to deserialize a PDU file directive header from raw memory.

src/fsfw/cfdp/pdu/FinishedPduCreator.cpp

@@ -1,5 +1,7 @@
 #include "FinishedPduCreator.h"
 
+#include "fsfw/globalfunctions/CRC.h"
+
 FinishPduCreator::FinishPduCreator(PduConfig &conf, FinishedInfo &finishInfo)
     : FileDirectiveCreator(conf, cfdp::FileDirective::FINISH, 0), finishInfo(finishInfo) {
   updateDirectiveFieldLen();
@@ -13,6 +15,7 @@ void FinishPduCreator::updateDirectiveFieldLen() {
 
 ReturnValue_t FinishPduCreator::serialize(uint8_t **buffer, size_t *size, size_t maxSize,
                                           Endianness streamEndianness) const {
+  const uint8_t *start = *buffer;
   ReturnValue_t result = FileDirectiveCreator::serialize(buffer, size, maxSize, streamEndianness);
   if (result != returnvalue::OK) {
     return result;
@@ -40,5 +43,9 @@ ReturnValue_t FinishPduCreator::serialize(uint8_t **buffer, size_t *size, size_t
   if (finishInfo.getFaultLocation(&entityId) == returnvalue::OK) {
     result = entityId->serialize(buffer, size, maxSize, streamEndianness);
   }
+  if (getCrcFlag()) {
+    uint16_t crc = CRC::crc16ccitt(start, getWholePduSize() - 2);
+    result = SerializeAdapter::serialize(&crc, buffer, size, maxSize, streamEndianness);
+  }
   return result;
 }

src/fsfw/cfdp/pdu/HeaderReader.cpp

@@ -1,8 +1,10 @@
+#include "HeaderReader.h"
+
 #include <fsfw/serialize/SerializeAdapter.h>
 
 #include <cstring>
 
-#include "PduHeaderReader.h"
+#include "fsfw/globalfunctions/CRC.h"
 
 PduHeaderReader::PduHeaderReader(const uint8_t *pduBuf, size_t maxSize) {
   setReadOnlyData(pduBuf, maxSize);
@@ -17,28 +19,29 @@ ReturnValue_t PduHeaderReader::parseData() {
   }
   pointers.fixedHeader =
       reinterpret_cast<PduHeaderFixedStruct *>(const_cast<uint8_t *>(pointers.rawPtr));
-  sourceIdRaw = static_cast<uint8_t *>(&pointers.fixedHeader->variableFieldsStart);
+  sourceIdRaw = &pointers.fixedHeader->variableFieldsStart;
   cfdp::WidthInBytes widthEntityIds = getLenEntityIds();
   cfdp::WidthInBytes widthSeqNum = getLenSeqNum();
   seqNumRaw = static_cast<uint8_t *>(sourceIdRaw) + static_cast<uint8_t>(widthEntityIds);
   destIdRaw = static_cast<uint8_t *>(seqNumRaw) + static_cast<uint8_t>(widthSeqNum);
   if (getWholePduSize() > PduHeaderReader::getHeaderSize()) {
-    pointers.dataFieldStart = reinterpret_cast<const uint8_t *>(destIdRaw) + widthEntityIds;
+    pointers.dataFieldStart = static_cast<const uint8_t *>(destIdRaw) + widthEntityIds;
   } else {
     pointers.dataFieldStart = nullptr;
   }
+
   return returnvalue::OK;
 }
 
-ReturnValue_t PduHeaderReader::setData(uint8_t *dataPtr, size_t maxSize_, void *args) {
+ReturnValue_t PduHeaderReader::setData(uint8_t *dataPtr, size_t maxSize, void *args) {
   if (dataPtr == nullptr) {
     return returnvalue::FAILED;
   }
-  if (maxSize_ < 7) {
+  if (maxSize < 7) {
     return SerializeIF::STREAM_TOO_SHORT;
   }
   pointers.rawPtr = dataPtr;
-  maxSize = maxSize_;
+  this->maxSize = maxSize;
   return returnvalue::OK;
 }
 
@@ -166,3 +169,12 @@ void PduHeaderReader::fillConfig(PduConfig &cfg) const {
 }
 
 const uint8_t *PduHeaderReader::getPduDataField() const { return pointers.dataFieldStart; }
+
+bool PduHeaderReader::performCrcCheckIfApplicable() const {
+  if (getCrcFlag()) {
+    if (CRC::crc16ccitt(pointers.rawPtr, getWholePduSize()) != 0) {
+      return false;
+    }
+  }
+  return true;
+}

src/fsfw/cfdp/pdu/HeaderReader.h

@@ -71,6 +71,11 @@ class PduHeaderReader : public RedirectableDataPointerIF, public PduHeaderIF {
   void getDestId(cfdp::EntityId& destId) const override;
   void getTransactionSeqNum(cfdp::TransactionSeqNum& seqNum) const override;
 
+  /**
+   * Performs the CRC check on the whole PDU if the CRC flag is set.
+   */
+  [[nodiscard]] bool performCrcCheckIfApplicable() const;
+
   ReturnValue_t deserResult = returnvalue::OK;
 
   [[nodiscard]] size_t getMaxSize() const;

src/fsfw/cfdp/pdu/KeepAlivePduCreator.cpp

@@ -1,5 +1,7 @@
 #include "KeepAlivePduCreator.h"
 
+#include "fsfw/globalfunctions/CRC.h"
+
 KeepAlivePduCreator::KeepAlivePduCreator(PduConfig &conf, cfdp::Fss &progress)
     : FileDirectiveCreator(conf, cfdp::FileDirective::KEEP_ALIVE, 4), progress(progress) {
   updateDirectiveFieldLen();
@@ -17,9 +19,18 @@ void KeepAlivePduCreator::updateDirectiveFieldLen() {
 
 ReturnValue_t KeepAlivePduCreator::serialize(uint8_t **buffer, size_t *size, size_t maxSize,
                                              Endianness streamEndianness) const {
+  const uint8_t *start = *buffer;
   ReturnValue_t result = FileDirectiveCreator::serialize(buffer, size, maxSize, streamEndianness);
   if (result != returnvalue::OK) {
     return result;
   }
-  return progress.serialize(this->getLargeFileFlag(), buffer, size, maxSize, streamEndianness);
+  result = progress.serialize(this->getLargeFileFlag(), buffer, size, maxSize, streamEndianness);
+  if (result != returnvalue::OK) {
+    return result;
+  }
+  if (getCrcFlag()) {
+    uint16_t crc = CRC::crc16ccitt(start, getWholePduSize() - 2);
+    result = SerializeAdapter::serialize(&crc, buffer, size, maxSize, streamEndianness);
+  }
+  return result;
 }

src/fsfw/cfdp/pdu/MetadataPduCreator.cpp

@@ -1,5 +1,7 @@
 #include "MetadataPduCreator.h"
 
+#include "fsfw/globalfunctions/CRC.h"
+
 MetadataPduCreator::MetadataPduCreator(PduConfig &conf, MetadataGenericInfo &info,
                                        cfdp::StringLv &srcFileName, cfdp::StringLv &destFileName,
                                        cfdp::Tlv **optionsArray, size_t optionsLen)
@@ -29,6 +31,7 @@ size_t MetadataPduCreator::getSerializedSize() const {
 
 ReturnValue_t MetadataPduCreator::serialize(uint8_t **buffer, size_t *size, size_t maxSize,
                                             Endianness streamEndianness) const {
+  const uint8_t *start = *buffer;
   ReturnValue_t result = FileDirectiveCreator::serialize(buffer, size, maxSize, streamEndianness);
   if (result != returnvalue::OK) {
     return result;
@@ -60,6 +63,11 @@ ReturnValue_t MetadataPduCreator::serialize(uint8_t **buffer, size_t *size, size
       }
     }
   }
+
+  if (getCrcFlag()) {
+    uint16_t crc = CRC::crc16ccitt(start, getWholePduSize() - 2);
+    result = SerializeAdapter::serialize(&crc, buffer, size, maxSize, streamEndianness);
+  }
   return result;
 }
 const cfdp::StringLv &MetadataPduCreator::getSourceFileName() const { return srcFileName; }

src/fsfw/cfdp/pdu/MetadataPduReader.cpp

@@ -38,6 +38,10 @@ ReturnValue_t MetadataPduReader::parseData() {
     return result;
   }
 
+  if (getCrcFlag() && remSize == 2) {
+    return returnvalue::OK;
+  }
+
   if (remSize > 0) {
     if (optionArrayMaxSize == 0 or optionArray == nullptr) {
       return cfdp::METADATA_CANT_PARSE_OPTIONS;

src/fsfw/cfdp/pdu/NakPduCreator.cpp

@@ -1,5 +1,7 @@
 #include "NakPduCreator.h"
 
+#include "fsfw/globalfunctions/CRC.h"
+
 NakPduCreator::NakPduCreator(PduConfig &pduConf, NakInfo &nakInfo)
     : FileDirectiveCreator(pduConf, cfdp::FileDirective::NAK, 0), nakInfo(nakInfo) {
   updateDirectiveFieldLen();
@@ -13,6 +15,7 @@ size_t NakPduCreator::getSerializedSize() const { return FileDirectiveCreator::g
 
 ReturnValue_t NakPduCreator::serialize(uint8_t **buffer, size_t *size, size_t maxSize,
                                        Endianness streamEndianness) const {
+  const uint8_t *start = *buffer;
   ReturnValue_t result = FileDirectiveCreator::serialize(buffer, size, maxSize, streamEndianness);
   if (result != returnvalue::OK) {
     return result;
@@ -40,5 +43,9 @@ ReturnValue_t NakPduCreator::serialize(uint8_t **buffer, size_t *size, size_t ma
       }
     }
   }
+  if (getCrcFlag()) {
+    uint16_t crc = CRC::crc16ccitt(start, getWholePduSize() - 2);
+    result = SerializeAdapter::serialize(&crc, buffer, size, maxSize, streamEndianness);
+  }
   return result;
 }

src/fsfw/cfdp/pdu/PromptPduCreator.cpp

@@ -1,5 +1,7 @@
 #include "PromptPduCreator.h"
 
+#include "fsfw/globalfunctions/CRC.h"
+
 PromptPduCreator::PromptPduCreator(PduConfig &conf, cfdp::PromptResponseRequired responseRequired)
     : FileDirectiveCreator(conf, cfdp::FileDirective::PROMPT, 1),
       responseRequired(responseRequired) {}
@@ -10,6 +12,7 @@ size_t PromptPduCreator::getSerializedSize() const {
 
 ReturnValue_t PromptPduCreator::serialize(uint8_t **buffer, size_t *size, size_t maxSize,
                                           Endianness streamEndianness) const {
+  const uint8_t *start = *buffer;
   ReturnValue_t result = FileDirectiveCreator::serialize(buffer, size, maxSize, streamEndianness);
   if (result != returnvalue::OK) {
     return result;
@@ -20,5 +23,10 @@ ReturnValue_t PromptPduCreator::serialize(uint8_t **buffer, size_t *size, size_t
   **buffer = responseRequired << 7;
   *buffer += 1;
   *size += 1;
+
+  if (getCrcFlag()) {
+    uint16_t crc = CRC::crc16ccitt(start, getWholePduSize() - 2);
+    result = SerializeAdapter::serialize(&crc, buffer, size, maxSize, streamEndianness);
+  }
   return result;
 }

src/fsfw/datapoollocal/LocalPoolDataSetBase.cpp

@@ -17,8 +17,7 @@ LocalPoolDataSetBase::LocalPoolDataSetBase(HasLocalDataPoolIF *hkOwner, uint32_t
   if (hkOwner == nullptr) {
     // Configuration error.
 #if FSFW_CPP_OSTREAM_ENABLED == 1
-    sif::error << "LocalPoolDataSetBase::LocalPoolDataSetBase: Owner "
+    sif::error << "LocalPoolDataSetBase::LocalPoolDataSetBase: Owner " << "invalid!" << std::endl;
-               << "invalid!" << std::endl;
 #else
     sif::printError(
         "LocalPoolDataSetBase::LocalPoolDataSetBase: Owner "
@@ -187,8 +186,8 @@ ReturnValue_t LocalPoolDataSetBase::serializeLocalPoolIds(uint8_t **buffer, size
         SerializeAdapter::serialize(&currentPoolId, buffer, size, maxSize, streamEndianness);
     if (result != returnvalue::OK) {
 #if FSFW_CPP_OSTREAM_ENABLED == 1
-      sif::warning << "LocalPoolDataSetBase::serializeLocalPoolIds: "
+      sif::warning << "LocalPoolDataSetBase::serializeLocalPoolIds: " << "Serialization error!"
-                   << "Serialization error!" << std::endl;
+                   << std::endl;
 #else
       sif::printWarning(
           "LocalPoolDataSetBase::serializeLocalPoolIds: "

src/fsfw/datapoollocal/LocalPoolObjectBase.cpp

@@ -17,8 +17,8 @@ LocalPoolObjectBase::LocalPoolObjectBase(lp_id_t poolId, HasLocalDataPoolIF* hkO
   }
   if (hkOwner == nullptr) {
 #if FSFW_CPP_OSTREAM_ENABLED == 1
-    sif::error << "LocalPoolVar<T>::LocalPoolVar: The supplied pool "
+    sif::error << "LocalPoolVar<T>::LocalPoolVar: The supplied pool " << "owner is a invalid!"
-               << "owner is a invalid!" << std::endl;
+               << std::endl;
 #endif
     return;
   }

src/fsfw/devicehandlers/DeviceHandlerFailureIsolation.cpp

@@ -243,8 +243,8 @@ bool DeviceHandlerFailureIsolation::isFdirInActionOrAreWeFaulty(EventMessage* ev
   if (owner == nullptr) {
     // Configuration error.
 #if FSFW_CPP_OSTREAM_ENABLED == 1
-    sif::error << "DeviceHandlerFailureIsolation::"
+    sif::error << "DeviceHandlerFailureIsolation::" << "isFdirInActionOrAreWeFaulty: Owner not set!"
-               << "isFdirInActionOrAreWeFaulty: Owner not set!" << std::endl;
+               << std::endl;
 #endif
     return false;
   }

src/fsfw/fdir/FailureIsolationBase.cpp

@@ -62,8 +62,7 @@ ReturnValue_t FailureIsolationBase::initialize() {
         ObjectManager::instance()->get<ConfirmsFailuresIF>(faultTreeParent);
     if (parentIF == nullptr) {
 #if FSFW_CPP_OSTREAM_ENABLED == 1
-      sif::error << "FailureIsolationBase::intialize: Parent object "
+      sif::error << "FailureIsolationBase::intialize: Parent object " << "invalid" << std::endl;
-                 << "invalid" << std::endl;
       sif::error << "Make sure it implements ConfirmsFailuresIF" << std::endl;
 #else
       sif::printError("FailureIsolationBase::intialize: Parent object invalid\n");

src/fsfw/filesystem/HasFileSystemIF.h

@@ -58,11 +58,7 @@ class HasFileSystemIF {
   static constexpr ReturnValue_t DIRECTORY_ALREADY_EXISTS = MAKE_RETURN_CODE(22);
   static constexpr ReturnValue_t NOT_A_DIRECTORY = MAKE_RETURN_CODE(23);
   static constexpr ReturnValue_t DIRECTORY_NOT_EMPTY = MAKE_RETURN_CODE(24);
-
+  static constexpr ReturnValue_t ELEMENT_DOES_NOT_EXIST = MAKE_RETURN_CODE(25);
-  //! [EXPORT] : P1: Sequence number missing
-  static constexpr ReturnValue_t SEQUENCE_PACKET_MISSING_WRITE = MAKE_RETURN_CODE(30);
-  //! [EXPORT] : P1: Sequence number missing
-  static constexpr ReturnValue_t SEQUENCE_PACKET_MISSING_READ = MAKE_RETURN_CODE(31);
 
   virtual ~HasFileSystemIF() = default;
 
@@ -75,21 +71,27 @@ class HasFileSystemIF {
   }
 
   // Get the base filename without the full directory path
-  virtual ReturnValue_t getBaseFilename(FilesystemParams params, char* nameBuf, size_t maxLen,
+  virtual ReturnValue_t getBaseFilename(const char* path, char* nameBuf, size_t maxLen,
                                         size_t& baseNameLen) = 0;
 
-  virtual bool isDirectory(const char* path) = 0;
+  virtual ReturnValue_t isDirectory(const char* path, bool& isDirectory) = 0;
 
-  virtual ReturnValue_t getFileSize(FilesystemParams params, uint64_t& fileSize) = 0;
+  virtual ReturnValue_t getFileSize(const char* path, uint64_t& fileSize,
+                                    FileSystemArgsIF* args) = 0;
+  virtual ReturnValue_t getFileSize(const char* path, uint64_t& fileSize) {
+    return getFileSize(path, fileSize, nullptr);
+  }
 
-  virtual bool fileExists(FilesystemParams params) = 0;
+  virtual bool fileExists(const char* path, FileSystemArgsIF* args) = 0;
+  virtual bool fileExists(const char* path) { return fileExists(path, nullptr); }
 
   /**
    * Truncate a file, deleting its contents and setting its size to 0 accordingly.
    * @param params
    * @return
    */
-  virtual ReturnValue_t truncateFile(FilesystemParams params) = 0;
+  virtual ReturnValue_t truncateFile(const char* path, FileSystemArgsIF* args) = 0;
+  virtual ReturnValue_t truncateFile(const char* path) { return truncateFile(path, nullptr); }
 
   /**
    * @brief   Generic function to write to a file.
@@ -100,32 +102,23 @@ class HasFileSystemIF {
    * @param fileOpInfo General information: File name, size to write, offset, additional arguments
    * @param data The data to write to the file
    */
-  virtual ReturnValue_t writeToFile(FileOpParams params, const uint8_t* data) = 0;
+  virtual ReturnValue_t writeToFile(const char* path, size_t offset, const uint8_t* data,
+                                    size_t size) = 0;
 
   /**
    * @brief Generic function to read from a file. This variant takes a pointer to a buffer and
    * performs pointer arithmetic by incrementing the pointer by the read size
-   * @param fileOpInfo General information: File name, size to write, offset, additional arguments
+   * @param path [in] file path
-   * @param buffer [in/out] Data will be read into the provided buffer, and the pointer will be
+   * @param offset [in] offset of data to read
-   *    incremented by the read length
+   * @param sizeToRead [in] size of data to read
-   * @param readSize [out] Will be incremented by the read length
+   * @param buffer [in/out] Data will be read into the provided buffer.
-   * @param maxSize Maximum size of the provided buffer
+   * @param actuallyRead [out] Will be set to the length actually read.
+   * @param maxSize [in] Maximum size of the provided buffer
    * @param args
    * @return
    */
-  virtual ReturnValue_t readFromFile(FileOpParams fileOpInfo, uint8_t** buffer, size_t& readSize,
+  virtual ReturnValue_t readFromFile(const char* path, size_t offset, size_t sizeToRead,
-                                     size_t maxSize) = 0;
+                                     uint8_t* buffer, size_t& actuallyRead, size_t maxSize) = 0;
-  /**
-   * Variant of the @readFromFile which does not perform pointer arithmetic.
-   * @param fileOpInfo General information: File name, size to write, offset, additional arguments
-   * @param buf
-   * @param maxSize
-   * @return
-   */
-  virtual ReturnValue_t readFromFile(FileOpParams fileOpInfo, uint8_t* buf, size_t maxSize) {
-    size_t dummy = 0;
-    return readFromFile(fileOpInfo, &buf, dummy, maxSize);
-  }
 
   /**
    * @brief   Generic function to create a new file.
@@ -136,10 +129,8 @@ class HasFileSystemIF {
    * @param args Any other arguments which an implementation might require
    * @return
    */
-  virtual ReturnValue_t createFile(FilesystemParams params) {
+  virtual ReturnValue_t createFile(const char* path) { return createFile(path, nullptr, 0); }
-    return createFile(params, nullptr, 0);
+  virtual ReturnValue_t createFile(const char* path, const uint8_t* data, size_t size) = 0;
-  }
-  virtual ReturnValue_t createFile(FilesystemParams params, const uint8_t* data, size_t size) = 0;
 
   /**
    * @brief   Generic function to delete a file.
@@ -159,9 +150,13 @@ class HasFileSystemIF {
    * @param args Any other arguments which an implementation might require
    * @return
    */
-  virtual ReturnValue_t createDirectory(FilesystemParams params, bool createParentDirs) = 0;
+  virtual ReturnValue_t createDirectory(const char* path, bool createParentDirs,
-  virtual ReturnValue_t createDirectory(FilesystemParams params) {
+                                        FileSystemArgsIF* args) = 0;
-    return createDirectory(params, false);
+  virtual ReturnValue_t createDirectory(const char* path, FileSystemArgsIF* args) {
+    return createDirectory(path, false, args);
+  }
+  virtual ReturnValue_t createDirectory(const char* path) {
+    return createDirectory(path, false, nullptr);
   }
 
   /**
@@ -169,9 +164,10 @@ class HasFileSystemIF {
    * @param repositoryPath
    * @param args Any other arguments which an implementation might require
    */
-  virtual ReturnValue_t removeDirectory(FilesystemParams params, bool deleteRecurively) = 0;
+  virtual ReturnValue_t removeDirectory(const char* path, bool deleteRecurively,
-  virtual ReturnValue_t removeDirectory(FilesystemParams params) {
+                                        FileSystemArgsIF* args) = 0;
-    return removeDirectory(params, false);
+  virtual ReturnValue_t removeDirectory(const char* path, FileSystemArgsIF* args) {
+    return removeDirectory(path, false, nullptr);
   }
 
   virtual ReturnValue_t rename(const char* oldPath, const char* newPath) {

src/fsfw/osal/common/TcpTmTcBridge.cpp

@@ -49,8 +49,8 @@ ReturnValue_t TcpTmTcBridge::handleTm() {
   MutexGuard guard(mutex, timeoutType, mutexTimeoutMs);
   TmTcMessage message;
   ReturnValue_t status = returnvalue::OK;
-  for (ReturnValue_t result = tmTcReceptionQueue->receiveMessage(&message);
+  for (ReturnValue_t result = tmtcReceptionQueue->receiveMessage(&message);
-       result == returnvalue::OK; result = tmTcReceptionQueue->receiveMessage(&message)) {
+       result == returnvalue::OK; result = tmtcReceptionQueue->receiveMessage(&message)) {
     status = storeDownlinkData(&message);
     if (status != returnvalue::OK) {
       break;

src/fsfw/osal/common/TcpTmTcServer.cpp

@@ -321,8 +321,8 @@ ReturnValue_t TcpTmTcServer::handleTcRingBufferData(size_t availableReadData) {
 #if FSFW_CPP_OSTREAM_ENABLED == 1
     // Possible configuration error, too much data or/and data coming in too fast,
     // requiring larger buffers
-    sif::warning << "TcpTmTcServer::handleServerOperation: Ring buffer reached "
+    sif::warning << "TcpTmTcServer::handleServerOperation: Ring buffer reached " << "fill count"
-                 << "fill count" << std::endl;
+                 << std::endl;
 #else
     sif::printWarning(
         "TcpTmTcServer::handleServerOperation: Ring buffer reached "

src/fsfw/pus/Service20ParameterManagement.cpp

@@ -49,8 +49,8 @@ ReturnValue_t Service20ParameterManagement::checkAndAcquireTargetID(object_id_t*
   if (SerializeAdapter::deSerialize(objectIdToSet, &tcData, &tcDataLen,
                                     SerializeIF::Endianness::BIG) != returnvalue::OK) {
 #if FSFW_CPP_OSTREAM_ENABLED == 1
-    sif::error << "Service20ParameterManagement::checkAndAcquireTargetID: "
+    sif::error << "Service20ParameterManagement::checkAndAcquireTargetID: " << "Invalid data."
-               << "Invalid data." << std::endl;
+               << std::endl;
 #else
     sif::printError(
         "Service20ParameterManagement::"

src/fsfw/pus/Service3Housekeeping.cpp

@@ -196,8 +196,8 @@ ReturnValue_t Service3Housekeeping::handleReply(const CommandMessage* reply,
 
     default:
 #if FSFW_CPP_OSTREAM_ENABLED == 1
-      sif::warning << "Service3Housekeeping::handleReply: Invalid reply with "
+      sif::warning << "Service3Housekeeping::handleReply: Invalid reply with " << "reply command "
-                   << "reply command " << command << std::endl;
+                   << command << std::endl;
 #else
       sif::printWarning(
           "Service3Housekeeping::handleReply: Invalid reply with "

src/fsfw/storagemanager/LocalPool.cpp

@@ -12,8 +12,7 @@ LocalPool::LocalPool(object_id_t setObjectId, const LocalPoolConfig& poolConfig,
       spillsToHigherPools(spillsToHigherPools) {
   if (NUMBER_OF_SUBPOOLS == 0) {
 #if FSFW_CPP_OSTREAM_ENABLED == 1
-    sif::error << "LocalPool::LocalPool: Passed pool configuration is "
+    sif::error << "LocalPool::LocalPool: Passed pool configuration is " << " invalid!" << std::endl;
-               << " invalid!" << std::endl;
 #endif
   }
   max_subpools_t index = 0;

src/fsfw/subsystem/Subsystem.cpp

@@ -38,10 +38,9 @@ ReturnValue_t Subsystem::checkSequence(HybridIterator<ModeListEntry> iter,
     if (!existsModeTable(iter->getTableId())) {
 #if FSFW_CPP_OSTREAM_ENABLED == 1
       using namespace std;
-      sif::warning << "Subsystem::checkSequence: "
+      sif::warning << "Subsystem::checkSequence: " << "Object " << setfill('0') << hex << "0x"
-                   << "Object " << setfill('0') << hex << "0x" << setw(8) << getObjectId()
+                   << setw(8) << getObjectId() << setw(0) << ": Mode table for mode ID " << "0x"
-                   << setw(0) << ": Mode table for mode ID "
+                   << setw(8) << iter->getTableId() << " does not exist" << dec << endl;
-                   << "0x" << setw(8) << iter->getTableId() << " does not exist" << dec << endl;
 #endif
       return TABLE_DOES_NOT_EXIST;
     } else {

src/fsfw/tasks/FixedSlotSequence.cpp

@@ -101,8 +101,7 @@ ReturnValue_t FixedSlotSequence::checkSequence() const {
     if (result != returnvalue::OK) {
       // Continue for now but print error output.
 #if FSFW_CPP_OSTREAM_ENABLED == 1
-      sif::error << "FixedSlotSequence::checkSequence:"
+      sif::error << "FixedSlotSequence::checkSequence:" << " Custom check failed!" << std::endl;
-                 << " Custom check failed!" << std::endl;
 #endif
     }
   }

src/fsfw/tcdistribution/PusDistributor.cpp

@@ -8,8 +8,8 @@
 
 #define PUS_DISTRIBUTOR_DEBUGGING 0
 
-PusDistributor::PusDistributor(uint16_t setApid, object_id_t setObjectId,
+PusDistributor::PusDistributor(uint16_t setApid, object_id_t setObjectId, StorageManagerIF* store_,
-                               CcsdsDistributorIF* distributor, StorageManagerIF* store_)
+                               CcsdsDistributorIF* distributor)
     : TcDistributorBase(setObjectId),
       store(store_),
       checker(setApid, ccsds::PacketType::TC),
@@ -122,14 +122,12 @@ ReturnValue_t PusDistributor::initialize() {
       return ObjectManagerIF::CHILD_INIT_FAILED;
     }
   }
-  if (ccsdsDistributor == nullptr) {
+  if (ccsdsDistributor != nullptr) {
-#if FSFW_CPP_OSTREAM_ENABLED == 1
+    ReturnValue_t result =
-    sif::error << "PUSDistributor::initialize: Packet source invalid" << std::endl;
+        ccsdsDistributor->registerApplication(CcsdsDistributorIF::DestInfo(*this, false));
-    sif::error << " Make sure it exists and implements CCSDSDistributorIF!" << std::endl;
+    if (result != returnvalue::OK) {
-#else
+      return result;
-    sif::printError("PusDistributor::initialize: Packet source invalid\n");
+    }
-    sif::printError("Make sure it exists and implements CcsdsDistributorIF\n");
-#endif
     return ObjectManagerIF::CHILD_INIT_FAILED;
   }
   if (verifyChannel == nullptr) {
@@ -139,7 +137,7 @@ ReturnValue_t PusDistributor::initialize() {
       return ObjectManagerIF::CHILD_INIT_FAILED;
     }
   }
-  return ccsdsDistributor->registerApplication(CcsdsDistributorIF::DestInfo(*this, false));
+  return SystemObject::initialize();
 }
 
 void PusDistributor::checkerFailurePrinter() const {

src/fsfw/tcdistribution/PusDistributor.h

@@ -31,8 +31,9 @@ class PusDistributor : public TcDistributorBase,
    * @param setPacketSource Object ID of the source of TC packets.
    * Must implement CcsdsDistributorIF.
    */
-  PusDistributor(uint16_t setApid, object_id_t setObjectId, CcsdsDistributorIF* packetSource,
+  PusDistributor(uint16_t setApid, object_id_t setObjectId, StorageManagerIF* store = nullptr,
-                 StorageManagerIF* store = nullptr);
+                 CcsdsDistributorIF* packetSource = nullptr);
+
   [[nodiscard]] const char* getName() const override;
   /**
    * The destructor is empty.

src/fsfw/tmtcpacket/ccsds/SpacePacketCreator.cpp

@@ -43,10 +43,11 @@ ReturnValue_t SpacePacketCreator::serialize(uint8_t **buffer, size_t *size, size
 
 void SpacePacketCreator::setCcsdsLenFromTotalDataFieldLen(size_t actualLength) {
   if (actualLength == 0) {
-    return;
+    setDataLenField(actualLength);
-  }
+  } else {
     setDataLenField(actualLength - 1);
   }
+}
 size_t SpacePacketCreator::getSerializedSize() const { return ccsds::HEADER_LEN; }
 
 ReturnValue_t SpacePacketCreator::deSerialize(const uint8_t **buffer, size_t *size,

src/fsfw/tmtcservices/TmTcBridge.cpp

@@ -17,11 +17,11 @@ TmTcBridge::TmTcBridge(const char* name, object_id_t objectId, object_id_t tcDes
 
 {
   auto mqArgs = MqArgs(objectId, static_cast<void*>(this));
-  tmTcReceptionQueue = QueueFactory::instance()->createMessageQueue(
+  tmtcReceptionQueue = QueueFactory::instance()->createMessageQueue(
       msgQueueDepth, MessageQueueMessage::MAX_MESSAGE_SIZE, &mqArgs);
 }
 
-TmTcBridge::~TmTcBridge() { QueueFactory::instance()->deleteMessageQueue(tmTcReceptionQueue); }
+TmTcBridge::~TmTcBridge() { QueueFactory::instance()->deleteMessageQueue(tmtcReceptionQueue); }
 
 void TmTcBridge::setNumberOfSentPacketsPerCycle(uint32_t sentPacketsPerCycle_) {
   this->sentPacketsPerCycle = sentPacketsPerCycle_;
@@ -34,8 +34,7 @@ ReturnValue_t TmTcBridge::setMaxNumberOfPacketsStored(unsigned int maxNumberOfPa
   } else {
 #if FSFW_CPP_OSTREAM_ENABLED == 1
     sif::warning << "TmTcBridge::setMaxNumberOfPacketsStored: Number of "
-                 << "packets stored exceeds limits. "
+                 << "packets stored exceeds limits. " << "Keeping default value." << std::endl;
-                 << "Keeping default value." << std::endl;
 #endif
     return returnvalue::FAILED;
   }
@@ -70,7 +69,7 @@ ReturnValue_t TmTcBridge::initialize() {
 
   tmFifo = new DynamicFIFO<store_address_t>(maxNumberOfPacketsStored);
 
-  tmTcReceptionQueue->setDefaultDestination(tcDistributor->getRequestQueue());
+  tmtcReceptionQueue->setDefaultDestination(tcDistributor->getRequestQueue());
   return returnvalue::OK;
 }
 
@@ -79,15 +78,13 @@ ReturnValue_t TmTcBridge::performOperation(uint8_t operationCode) {
   result = handleTc();
   if (result != returnvalue::OK) {
 #if FSFW_CPP_OSTREAM_ENABLED == 1
-    sif::debug << "TmTcBridge::performOperation: "
+    sif::debug << "TmTcBridge::performOperation: " << "Error handling TCs" << std::endl;
-               << "Error handling TCs" << std::endl;
 #endif
   }
   result = handleTm();
   if (result != returnvalue::OK) {
 #if FSFW_CPP_OSTREAM_ENABLED == 1
-    sif::debug << "TmTcBridge::performOperation: "
+    sif::debug << "TmTcBridge::performOperation: " << "Error handling TMs" << std::endl;
-               << "Error handling TMs" << std::endl;
 #endif
   }
   return result;
@@ -124,8 +121,8 @@ ReturnValue_t TmTcBridge::handleTmQueue() {
   const uint8_t* data = nullptr;
   size_t size = 0;
   ReturnValue_t status = returnvalue::OK;
-  for (ReturnValue_t result = tmTcReceptionQueue->receiveMessage(&message);
+  for (ReturnValue_t result = tmtcReceptionQueue->receiveMessage(&message);
-       result == returnvalue::OK; result = tmTcReceptionQueue->receiveMessage(&message)) {
+       result == returnvalue::OK; result = tmtcReceptionQueue->receiveMessage(&message)) {
 #if FSFW_VERBOSE_LEVEL >= 3
 #if FSFW_CPP_OSTREAM_ENABLED == 1
     sif::info << "Sent packet counter: " << static_cast<int>(packetSentCounter) << std::endl;
@@ -241,7 +238,7 @@ void TmTcBridge::registerCommDisconnect() {
 }
 
 MessageQueueId_t TmTcBridge::getReportReceptionQueue(uint8_t virtualChannel) const {
-  return tmTcReceptionQueue->getId();
+  return tmtcReceptionQueue->getId();
 }
 
 void TmTcBridge::printData(uint8_t* data, size_t dataLen) { arrayprinter::print(data, dataLen); }
@@ -253,7 +250,7 @@ uint32_t TmTcBridge::getIdentifier() const {
 
 MessageQueueId_t TmTcBridge::getRequestQueue() const {
   // Default implementation: Relay TC messages to TC distributor directly.
-  return tmTcReceptionQueue->getDefaultDestination();
+  return tmtcReceptionQueue->getDefaultDestination();
 }
 
 void TmTcBridge::setFifoToOverwriteOldData(bool overwriteOld) { this->overwriteOld = overwriteOld; }

src/fsfw/tmtcservices/TmTcBridge.h

@@ -80,7 +80,7 @@ class TmTcBridge : public AcceptsTelemetryIF,
 
   //! Used to send and receive TMTC messages.
   //! The TmTcMessage class is used to transport messages between tasks.
-  MessageQueueIF* tmTcReceptionQueue = nullptr;
+  MessageQueueIF* tmtcReceptionQueue = nullptr;
 
   StorageManagerIF* tmStore = nullptr;
   StorageManagerIF* tcStore = nullptr;

src/fsfw_hal/host/HostFilesystem.cpp

@@ -10,11 +10,12 @@ using namespace std;
 
 HostFilesystem::HostFilesystem() = default;
 
-ReturnValue_t HostFilesystem::writeToFile(FileOpParams params, const uint8_t *data) {
+ReturnValue_t HostFilesystem::writeToFile(const char *path_, size_t offset, const uint8_t *data,
-  if (params.path() == nullptr) {
+                                          size_t size) {
+  if (path_ == nullptr) {
     return returnvalue::FAILED;
   }
-  path path(params.path());
+  path path(path_);
   std::error_code e;
   if (not exists(path, e)) {
     return HasFileSystemIF::FILE_DOES_NOT_EXIST;
@@ -25,17 +26,20 @@ ReturnValue_t HostFilesystem::writeToFile(FileOpParams params, const uint8_t *da
   if (file.fail()) {
     return HasFileSystemIF::GENERIC_FILE_ERROR;
   }
-  file.seekp(static_cast<unsigned int>(params.offset));
+  file.seekp(static_cast<unsigned int>(offset));
-  file.write(reinterpret_cast<const char *>(data), static_cast<unsigned int>(params.size));
+  file.write(reinterpret_cast<const char *>(data), static_cast<unsigned int>(size));
   return returnvalue::OK;
 }
 
-ReturnValue_t HostFilesystem::readFromFile(FileOpParams params, uint8_t **buffer, size_t &readSize,
+ReturnValue_t HostFilesystem::readFromFile(const char *path_, size_t offset, size_t sizeToRead,
-                                           size_t maxSize) {
+                                           uint8_t *buffer, size_t &actuallyRead, size_t maxSize) {
-  if (params.path() == nullptr) {
+  if (path_ == nullptr) {
     return returnvalue::FAILED;
   }
-  path path(params.path());
+  if (sizeToRead > maxSize) {
+    return SerializeIF::BUFFER_TOO_SHORT;
+  }
+  path path(path_);
   std::error_code e;
   if (not exists(path, e)) {
     return HasFileSystemIF::FILE_DOES_NOT_EXIST;
@@ -44,23 +48,17 @@ ReturnValue_t HostFilesystem::readFromFile(FileOpParams params, uint8_t **buffer
   if (file.fail()) {
     return HasFileSystemIF::GENERIC_FILE_ERROR;
   }
-  auto sizeToRead = static_cast<unsigned int>(params.size);
+  file.seekg(static_cast<unsigned int>(offset));
-  file.seekg(static_cast<unsigned int>(params.offset));
+  file.read(reinterpret_cast<char *>(buffer), static_cast<long>(sizeToRead));
-  if (readSize + sizeToRead > maxSize) {
+  actuallyRead = sizeToRead;
-    return SerializeIF::BUFFER_TOO_SHORT;
-  }
-  file.read(reinterpret_cast<char *>(*buffer), sizeToRead);
-  readSize += sizeToRead;
-  *buffer += sizeToRead;
   return returnvalue::OK;
 }
 
-ReturnValue_t HostFilesystem::createFile(FilesystemParams params, const uint8_t *data,
+ReturnValue_t HostFilesystem::createFile(const char *path_, const uint8_t *data, size_t size) {
-                                         size_t size) {
+  if (path_ == nullptr) {
-  if (params.path == nullptr) {
     return returnvalue::FAILED;
   }
-  path path(params.path);
+  std::filesystem::path path(path_);
   std::error_code e;
   if (exists(path, e)) {
     return HasFileSystemIF::FILE_ALREADY_EXISTS;
@@ -87,11 +85,12 @@ ReturnValue_t HostFilesystem::removeFile(const char *path_, FileSystemArgsIF *ar
   return HasFileSystemIF::GENERIC_FILE_ERROR;
 }
 
-ReturnValue_t HostFilesystem::createDirectory(FilesystemParams params, bool createParentDirs) {
+ReturnValue_t HostFilesystem::createDirectory(const char *path, bool createParentDirs,
-  if (params.path == nullptr) {
+                                              FileSystemArgsIF *args) {
+  if (path == nullptr) {
     return returnvalue::FAILED;
   }
-  path dirPath(params.path);
+  std::filesystem::path dirPath(path);
 
   std::error_code e;
   if (exists(dirPath, e)) {
@@ -110,11 +109,12 @@ ReturnValue_t HostFilesystem::createDirectory(FilesystemParams params, bool crea
   return HasFileSystemIF::GENERIC_DIR_ERROR;
 }
 
-ReturnValue_t HostFilesystem::removeDirectory(FilesystemParams params, bool deleteRecurively) {
+ReturnValue_t HostFilesystem::removeDirectory(const char *path, bool deleteRecurively,
-  if (params.path == nullptr) {
+                                              FileSystemArgsIF *args) {
+  if (path == nullptr) {
     return returnvalue::FAILED;
   }
-  path dirPath(params.path);
+  std::filesystem::path dirPath(path);
   std::error_code e;
   if (not exists(dirPath, e)) {
     return HasFileSystemIF::DIRECTORY_DOES_NOT_EXIST;
@@ -153,14 +153,14 @@ ReturnValue_t HostFilesystem::rename(const char *oldPath_, const char *newPath_,
   return returnvalue::OK;
 }
 
-bool HostFilesystem::fileExists(FilesystemParams params) {
+bool HostFilesystem::fileExists(const char *path_, FileSystemArgsIF *args) {
-  path path(params.path);
+  std::filesystem::path path(path_);
   std::error_code e;
   return filesystem::exists(path, e);
 }
 
-ReturnValue_t HostFilesystem::truncateFile(FilesystemParams params) {
+ReturnValue_t HostFilesystem::truncateFile(const char *path_, FileSystemArgsIF *args) {
-  path path(params.path);
+  std::filesystem::path path(path_);
   std::error_code e;
   if (not filesystem::exists(path, e)) {
     return FILE_DOES_NOT_EXIST;
@@ -170,12 +170,19 @@ ReturnValue_t HostFilesystem::truncateFile(FilesystemParams params) {
   return returnvalue::OK;
 }
 
-bool HostFilesystem::isDirectory(const char *path) { return filesystem::is_directory(path); }
+ReturnValue_t HostFilesystem::isDirectory(const char *path, bool &isDirectory) {
+  isDirectory = filesystem::is_directory(path);
+  return returnvalue::OK;
+}
 
-ReturnValue_t HostFilesystem::getBaseFilename(FilesystemParams params, char *nameBuf, size_t maxLen,
+ReturnValue_t HostFilesystem::getBaseFilename(const char *path, char *nameBuf, size_t maxLen,
                                               size_t &baseNameLen) {
-  std::string path(params.path);
+  std::string pathAsStr(path);
-  std::string baseName = path.substr(path.find_last_of("/\\") + 1);
+  size_t lastPos = pathAsStr.find_last_of("/\\");
+  if (lastPos == std::string::npos) {
+    return returnvalue::FAILED;
+  }
+  std::string baseName = pathAsStr.substr(pathAsStr.find_last_of("/\\") + 1);
   if (baseName.size() + 1 > maxLen) {
     return returnvalue::FAILED;
   }
@@ -185,10 +192,11 @@ ReturnValue_t HostFilesystem::getBaseFilename(FilesystemParams params, char *nam
   return returnvalue::OK;
 }
 
-ReturnValue_t HostFilesystem::getFileSize(FilesystemParams params, uint64_t &fileSize) {
+ReturnValue_t HostFilesystem::getFileSize(const char *path, uint64_t &fileSize,
-  if (!fileExists(params)) {
+                                          FileSystemArgsIF *args) {
+  if (!fileExists(path, args)) {
     return HasFileSystemIF::FILE_DOES_NOT_EXIST;
   }
-  fileSize = std::filesystem::file_size(params.path);
+  fileSize = std::filesystem::file_size(path);
   return returnvalue::OK;
 }

src/fsfw_hal/host/HostFilesystem.h

@@ -9,19 +9,23 @@ class HostFilesystem : public HasFileSystemIF {
  public:
   HostFilesystem();
 
-  ReturnValue_t getBaseFilename(FilesystemParams params, char *nameBuf, size_t maxLen,
+  ReturnValue_t getBaseFilename(const char *path, char *nameBuf, size_t maxLen,
                                 size_t &baseNameLen) override;
-  virtual ReturnValue_t getFileSize(FilesystemParams params, uint64_t &fileSize) override;
+  virtual ReturnValue_t getFileSize(const char *path, uint64_t &fileSize,
-  bool isDirectory(const char *path) override;
+                                    FileSystemArgsIF *args) override;
-  bool fileExists(FilesystemParams params) override;
+  ReturnValue_t isDirectory(const char *path, bool &isDirectory) override;
-  ReturnValue_t truncateFile(FilesystemParams params) override;
+  bool fileExists(const char *path, FileSystemArgsIF *args) override;
-  ReturnValue_t writeToFile(FileOpParams params, const uint8_t *data) override;
+  ReturnValue_t truncateFile(const char *path, FileSystemArgsIF *args) override;
-  ReturnValue_t readFromFile(FileOpParams fileOpInfo, uint8_t **buffer, size_t &readSize,
+  ReturnValue_t writeToFile(const char *path, size_t offset, const uint8_t *data,
-                             size_t maxSize) override;
+                            size_t size) override;
-  ReturnValue_t createFile(FilesystemParams params, const uint8_t *data, size_t size) override;
+  ReturnValue_t readFromFile(const char *path, size_t offset, size_t sizeToRead, uint8_t *buffer,
+                             size_t &actuallyRead, size_t maxSize) override;
+  ReturnValue_t createFile(const char *path, const uint8_t *data, size_t size) override;
   ReturnValue_t removeFile(const char *path, FileSystemArgsIF *args) override;
-  ReturnValue_t createDirectory(FilesystemParams params, bool createParentDirs) override;
+  ReturnValue_t createDirectory(const char *path, bool createParentDirs,
-  ReturnValue_t removeDirectory(FilesystemParams params, bool deleteRecurively) override;
+                                FileSystemArgsIF *args) override;
+  ReturnValue_t removeDirectory(const char *path, bool deleteRecurively,
+                                FileSystemArgsIF *args) override;
   ReturnValue_t rename(const char *oldPath, const char *newPath, FileSystemArgsIF *args) override;
 
   std::error_code errorCode;

src/fsfw_hal/linux/gpio/LinuxLibgpioIF.cpp

@@ -418,8 +418,8 @@ ReturnValue_t LinuxLibgpioIF::checkForConflictsById(gpioId_t gpioIdToCheck,
 #if FSFW_CPP_OSTREAM_ENABLED == 1
     sif::warning << "LinuxLibgpioIF::checkForConflictsRegularGpio: Duplicate GPIO "
                     "definition with ID "
-                 << gpioIdToCheck << " detected. "
+                 << gpioIdToCheck << " detected. " << "Duplicate will be removed from map to add"
-                 << "Duplicate will be removed from map to add" << std::endl;
+                 << std::endl;
 #else
     sif::printWarning(
         "LinuxLibgpioIF::checkForConflictsRegularGpio: Duplicate GPIO definition "

src/fsfw_hal/linux/i2c/I2cComIF.cpp

@@ -49,8 +49,7 @@ ReturnValue_t I2cComIF::initializeInterface(CookieIF* cookie) {
     if (not statusPair.second) {
 #if FSFW_CPP_OSTREAM_ENABLED == 1
       sif::error << "I2cComIF::initializeInterface: Failed to insert device with address "
-                 << i2cAddress << "to I2C device "
+                 << i2cAddress << "to I2C device " << "map" << std::endl;
-                 << "map" << std::endl;
 #endif
       return returnvalue::FAILED;
     }
@@ -91,8 +90,8 @@ ReturnValue_t I2cComIF::sendMessage(CookieIF* cookie, const uint8_t* sendData, s
   auto i2cDeviceMapIter = i2cDeviceMap.find(i2cAddress);
   if (i2cDeviceMapIter == i2cDeviceMap.end()) {
 #if FSFW_CPP_OSTREAM_ENABLED == 1
-    sif::error << "I2cComIF::sendMessage: i2cAddress of Cookie not "
+    sif::error << "I2cComIF::sendMessage: i2cAddress of Cookie not " << "registered in i2cDeviceMap"
-               << "registered in i2cDeviceMap" << std::endl;
+               << std::endl;
 #endif
     return returnvalue::FAILED;
   }

src/fsfw_hal/linux/spi/SpiComIF.cpp

@@ -197,9 +197,8 @@ ReturnValue_t SpiComIF::performRegularSendOperation(SpiCookie* spiCookie, const
       if (result == MutexIF::MUTEX_TIMEOUT) {
         sif::error << "SpiComIF::sendMessage: Lock timeout" << std::endl;
       } else {
-        sif::error << "SpiComIF::sendMessage: Failed to lock mutex with code "
+        sif::error << "SpiComIF::sendMessage: Failed to lock mutex with code " << "0x" << std::hex
-                   << "0x" << std::hex << std::setfill('0') << std::setw(4) << result << std::dec
+                   << std::setfill('0') << std::setw(4) << result << std::dec << std::endl;
-                   << std::endl;
       }
 #else
       sif::printError("SpiComIF::sendMessage: Failed to lock mutex with code %d\n", result);
@@ -307,9 +306,8 @@ ReturnValue_t SpiComIF::performHalfDuplexReception(SpiCookie* spiCookie) {
     if (result != returnvalue::OK) {
 #if FSFW_VERBOSE_LEVEL >= 1
 #if FSFW_CPP_OSTREAM_ENABLED == 1
-      sif::error << "SpiComIF::sendMessage: Failed to lock mutex with code "
+      sif::error << "SpiComIF::sendMessage: Failed to lock mutex with code " << "0x" << std::hex
-                 << "0x" << std::hex << std::setfill('0') << std::setw(4) << result << std::dec
+                 << std::setfill('0') << std::setw(4) << result << std::dec << std::endl;
-                 << std::endl;
 #else
       sif::printError("SpiComIF::sendMessage: Failed to lock mutex with code %d\n", result);
 #endif

unittests/cfdp/CMakeLists.txt

@@ -1,6 +1,7 @@
 target_sources(
-  ${FSFW_TEST_TGT} PRIVATE testCfdp.cpp testOtherTlvs.cpp
+  ${FSFW_TEST_TGT}
-                           testReservedMsgCreator.cpp testTlv.cpp testLvs.cpp)
+  PRIVATE testCfdp.cpp testOtherTlvs.cpp testReservedMsgCreator.cpp testTlv.cpp
+          testLvs.cpp PduSenderMock.cpp)
 
 add_subdirectory(handler)
 add_subdirectory(pdu)

unittests/cfdp/PduSenderMock.cpp

@@ -0,0 +1 @@
+#include "PduSenderMock.h"

unittests/cfdp/PduSenderMock.h

@@ -0,0 +1,36 @@
+#pragma once
+#include <deque>
+#include <vector>
+
+#include "fsfw/cfdp/handler/PduSenderIF.h"
+
+struct SentPdu {
+  cfdp::PduType pduType;
+  std::optional<cfdp::FileDirective> fileDirective;
+  std::vector<uint8_t> rawPdu;
+};
+
+class PduSenderMock : public cfdp::PduSenderIF {
+ public:
+  ReturnValue_t sendPdu(cfdp::PduType pduType, std::optional<cfdp::FileDirective> fileDirective,
+
+                        const uint8_t* pdu, size_t pduSize) override {
+    SentPdu sentPdu;
+    sentPdu.pduType = pduType;
+    sentPdu.fileDirective = fileDirective;
+    sentPdu.rawPdu = std::vector(pdu, pdu + pduSize);
+    sentPdus.push_back(sentPdu);
+    return returnvalue::OK;
+  }
+
+  std::optional<SentPdu> getNextSentPacket() {
+    if (sentPdus.empty()) {
+      return std::nullopt;
+    }
+    SentPdu nextPdu = sentPdus.front();
+    sentPdus.pop_front();
+    return nextPdu;
+  }
+
+  std::deque<SentPdu> sentPdus;
+};

unittests/cfdp/handler/OwnedPduPacket.h

@@ -0,0 +1,31 @@
+#pragma once
+
+#include <optional>
+#include <vector>
+
+#include "fsfw/cfdp/definitions.h"
+#include "fsfw/cfdp/handler/PduPacketIF.h"
+
+namespace cfdp {
+
+class OwnedPduPacket : public PduPacketIF {
+ public:
+  OwnedPduPacket(PduType pduType, std::optional<FileDirective> fileDirective, const uint8_t* rawPdu,
+                 size_t pduLen)
+      : pduType(pduType), fileDirective(fileDirective), rawPdu(rawPdu, rawPdu + pduLen) {}
+
+  [[nodiscard]] cfdp::PduType getPduType() const override { return pduType; };
+  [[nodiscard]] std::optional<cfdp::FileDirective> getFileDirective() const override {
+    return fileDirective;
+  };
+  [[nodiscard]] const uint8_t* getRawPduData(size_t& pduLen) const override {
+    pduLen = rawPdu.size();
+    return rawPdu.data();
+  }
+
+  PduType pduType;
+  std::optional<FileDirective> fileDirective;
+  std::vector<uint8_t> rawPdu;
+};
+
+}  // namespace cfdp

unittests/cfdp/handler/testDestHandler.cpp

@@ -4,6 +4,8 @@
 #include <random>
 #include <utility>
 
+#include "OwnedPduPacket.h"
+#include "cfdp/PduSenderMock.h"
 #include "fsfw/cfdp.h"
 #include "fsfw/cfdp/pdu/EofPduCreator.h"
 #include "fsfw/cfdp/pdu/FileDataCreator.h"
@@ -23,60 +25,49 @@ TEST_CASE("CFDP Dest Handler", "[cfdp]") {
   MessageQueueId_t destQueueId = 2;
   AcceptsTmMock tmReceiver(destQueueId);
   MessageQueueMock mqMock(destQueueId);
-  EntityId localId = EntityId(UnsignedByteField<uint16_t>(2));
+  auto localId = EntityId(UnsignedByteField<uint16_t>(2));
-  EntityId remoteId = EntityId(UnsignedByteField<uint16_t>(3));
+  auto remoteId = EntityId(UnsignedByteField<uint16_t>(3));
   FaultHandlerMock fhMock;
   LocalEntityCfg localEntityCfg(localId, IndicationCfg(), fhMock);
   FilesystemMock fsMock;
   UserMock userMock(fsMock);
   RemoteConfigTableMock remoteCfgTableMock;
-  PacketInfoList<64> packetInfoList;
   LostSegmentsList<128> lostSegmentsList;
-  DestHandlerParams dp(localEntityCfg, userMock, remoteCfgTableMock, packetInfoList,
+  DestHandlerParams dp(localEntityCfg, userMock, remoteCfgTableMock, lostSegmentsList);
-                       lostSegmentsList);
   EventReportingProxyMock eventReporterMock;
   LocalPool::LocalPoolConfig storeCfg = {{10, 32}, {10, 64}, {10, 128}, {10, 1024}};
-  StorageManagerMock tcStore(2, storeCfg);
+  PduSenderMock senderMock;
-  StorageManagerMock tmStore(3, storeCfg);
+  FsfwParams fp(&eventReporterMock);
-  FsfwParams fp(tmReceiver, &mqMock, &eventReporterMock);
   RemoteEntityCfg cfg(remoteId);
   remoteCfgTableMock.addRemoteConfig(cfg);
-  fp.tcStore = &tcStore;
+  std::array<uint8_t, 4096> pduBuf{};
-  fp.tmStore = &tmStore;
-  uint8_t* buf = nullptr;
   size_t serLen = 0;
   store_address_t storeId;
   PduConfig conf;
-  auto destHandler = DestHandler(dp, fp);
+  auto destHandler = DestHandler(senderMock, 4096, dp, fp);
-  CHECK(destHandler.initialize() == OK);
 
   auto metadataPreparation = [&](Fss cfdpFileSize, ChecksumType checksumType) {
-    std::string srcNameString = "hello.txt";
+    const std::string srcNameString = "hello.txt";
-    std::string destNameString = "hello-cpy.txt";
+    const std::string destNameString = "hello-cpy.txt";
     StringLv srcName(srcNameString);
     StringLv destName(destNameString);
     MetadataGenericInfo info(false, checksumType, std::move(cfdpFileSize));
-    TransactionSeqNum seqNum(UnsignedByteField<uint16_t>(1));
+    const TransactionSeqNum seqNum(UnsignedByteField<uint16_t>(1));
     conf.sourceId = remoteId;
     conf.destId = localId;
     conf.mode = TransmissionMode::UNACKNOWLEDGED;
     conf.seqNum = seqNum;
-    MetadataPduCreator metadataCreator(conf, info, srcName, destName, nullptr, 0);
+    const MetadataPduCreator metadataCreator(conf, info, srcName, destName, nullptr, 0);
-    REQUIRE(tcStore.getFreeElement(&storeId, metadataCreator.getSerializedSize(), &buf) == OK);
+    REQUIRE(metadataCreator.serialize(pduBuf.data(), serLen, metadataCreator.getSerializedSize()) ==
-    REQUIRE(metadataCreator.serialize(buf, serLen, metadataCreator.getSerializedSize()) == OK);
+            OK);
-    PacketInfo packetInfo(metadataCreator.getPduType(), storeId,
+    return OwnedPduPacket(metadataCreator.getPduType(), metadataCreator.getDirectiveCode(),
-                          metadataCreator.getDirectiveCode());
+                          pduBuf.data(), serLen);
-    packetInfoList.push_back(packetInfo);
   };
 
   auto metadataCheck = [&](const cfdp::DestHandler::FsmResult& res, const char* sourceName,
                            const char* destName, size_t fileLen) {
     REQUIRE(res.result == OK);
-    REQUIRE(res.callStatus == CallStatus::CALL_AGAIN);
     REQUIRE(res.errors == 0);
-    // Assert that the packet was deleted after handling
-    REQUIRE(not tcStore.hasDataAtId(storeId));
-    REQUIRE(packetInfoList.empty());
     REQUIRE(userMock.metadataRecvd.size() == 1);
     auto& idMetadataPair = userMock.metadataRecvd.back();
     REQUIRE(idMetadataPair.first == destHandler.getTransactionId());
@@ -94,10 +85,10 @@ TEST_CASE("CFDP Dest Handler", "[cfdp]") {
   auto eofPreparation = [&](Fss cfdpFileSize, uint32_t crc) {
     EofInfo eofInfo(cfdp::ConditionCode::NO_ERROR, crc, std::move(cfdpFileSize));
     EofPduCreator eofCreator(conf, eofInfo);
-    REQUIRE(tcStore.getFreeElement(&storeId, eofCreator.getSerializedSize(), &buf) == OK);
+    REQUIRE(eofCreator.serialize(pduBuf.data(), serLen, eofCreator.getSerializedSize()) == OK);
-    REQUIRE(eofCreator.serialize(buf, serLen, eofCreator.getSerializedSize()) == OK);
+    OwnedPduPacket packet(eofCreator.getPduType(), eofCreator.getDirectiveCode(), pduBuf.data(),
-    PacketInfo packetInfo(eofCreator.getPduType(), storeId, eofCreator.getDirectiveCode());
+                          serLen);
-    packetInfoList.push_back(packetInfo);
+    return packet;
   };
 
   auto eofCheck = [&](const cfdp::DestHandler::FsmResult& res, const TransactionId& id) {
@@ -105,9 +96,6 @@ TEST_CASE("CFDP Dest Handler", "[cfdp]") {
     REQUIRE(res.state == CfdpState::IDLE);
     REQUIRE(res.errors == 0);
     REQUIRE(res.step == DestHandler::TransactionStep::IDLE);
-    // Assert that the packet was deleted after handling
-    REQUIRE(not tcStore.hasDataAtId(storeId));
-    REQUIRE(packetInfoList.empty());
     REQUIRE(userMock.eofRecvdRecvd.size() == 1);
     auto& eofId = userMock.eofRecvdRecvd.back();
     CHECK(eofId == id);
@@ -122,10 +110,6 @@ TEST_CASE("CFDP Dest Handler", "[cfdp]") {
     REQUIRE(res.result == OK);
     REQUIRE(res.state == CfdpState::BUSY_CLASS_1_NACKED);
     REQUIRE(res.step == DestHandler::TransactionStep::RECEIVING_FILE_DATA_PDUS);
-    for (const auto id : idsToCheck) {
-      REQUIRE(not tcStore.hasDataAtId(id));
-    }
-    REQUIRE(packetInfoList.empty());
   };
 
   SECTION("State") {
@@ -134,62 +118,59 @@ TEST_CASE("CFDP Dest Handler", "[cfdp]") {
   }
 
   SECTION("Idle State Machine Iteration") {
-    auto res = destHandler.stateMachine();
+    auto [packetsSent, result, step, state, errors, errorCodes] =
-    CHECK(res.result == OK);
+        destHandler.stateMachineNoPacket();
-    CHECK(res.callStatus == CallStatus::CALL_AFTER_DELAY);
+    CHECK(result == OK);
-    CHECK(res.errors == 0);
+    CHECK(errors == 0);
     CHECK(destHandler.getCfdpState() == CfdpState::IDLE);
     CHECK(destHandler.getTransactionStep() == DestHandler::TransactionStep::IDLE);
   }
 
   SECTION("Empty File Transfer") {
-    const DestHandler::FsmResult& res = destHandler.stateMachine();
+    const DestHandler::FsmResult& res = destHandler.stateMachineNoPacket();
     CHECK(res.result == OK);
     Fss cfdpFileSize(0);
-    metadataPreparation(cfdpFileSize, ChecksumType::NULL_CHECKSUM);
+    auto packet = metadataPreparation(cfdpFileSize, ChecksumType::NULL_CHECKSUM);
-    destHandler.stateMachine();
+    destHandler.stateMachine(packet);
     metadataCheck(res, "hello.txt", "hello-cpy.txt", 0);
-    destHandler.stateMachine();
+    destHandler.stateMachine(packet);
-    REQUIRE(res.callStatus == CallStatus::CALL_AFTER_DELAY);
+    // REQUIRE(res.callStatus == CallStatus::CALL_AFTER_DELAY);
     auto transactionId = destHandler.getTransactionId();
-    eofPreparation(cfdpFileSize, 0);
+    auto ownedEofPacket = eofPreparation(cfdpFileSize, 0);
     // After EOF, operation is done because no closure was requested
-    destHandler.stateMachine();
+    destHandler.stateMachine(ownedEofPacket);
     eofCheck(res, transactionId);
   }
 
   SECTION("Small File Transfer") {
-    const DestHandler::FsmResult& res = destHandler.stateMachine();
+    const DestHandler::FsmResult& res = destHandler.stateMachineNoPacket();
     CHECK(res.result == OK);
     std::string fileData = "hello test data";
     etl::crc32 crcCalc;
     crcCalc.add(fileData.begin(), fileData.end());
     uint32_t crc32 = crcCalc.value();
     Fss cfdpFileSize(fileData.size());
-    metadataPreparation(cfdpFileSize, ChecksumType::CRC_32);
+    auto metadataPacket = metadataPreparation(cfdpFileSize, ChecksumType::CRC_32);
-    destHandler.stateMachine();
+    destHandler.stateMachine(metadataPacket);
     metadataCheck(res, "hello.txt", "hello-cpy.txt", fileData.size());
-    destHandler.stateMachine();
+    destHandler.stateMachineNoPacket();
-    REQUIRE(res.callStatus == CallStatus::CALL_AFTER_DELAY);
     auto transactionId = destHandler.getTransactionId();
     Fss offset(0);
     FileDataInfo fdPduInfo(offset, reinterpret_cast<const uint8_t*>(fileData.data()),
                            fileData.size());
     FileDataCreator fdPduCreator(conf, fdPduInfo);
-    REQUIRE(tcStore.getFreeElement(&storeId, fdPduCreator.getSerializedSize(), &buf) == OK);
+    REQUIRE(fdPduCreator.serialize(pduBuf.data(), serLen, fdPduCreator.getSerializedSize()) == OK);
-    REQUIRE(fdPduCreator.serialize(buf, serLen, fdPduCreator.getSerializedSize()) == OK);
+    OwnedPduPacket fdPdu(fdPduCreator.getPduType(), std::nullopt, pduBuf.data(), serLen);
-    PacketInfo packetInfo(fdPduCreator.getPduType(), storeId, std::nullopt);
+    destHandler.stateMachine(fdPdu);
-    packetInfoList.push_back(packetInfo);
-    destHandler.stateMachine();
     fileDataPduCheck(res, {storeId});
-    eofPreparation(cfdpFileSize, crc32);
+    auto eofPacket = eofPreparation(cfdpFileSize, crc32);
     // After EOF, operation is done because no closure was requested
-    destHandler.stateMachine();
+    destHandler.stateMachine(eofPacket);
     eofCheck(res, transactionId);
   }
 
   SECTION("Segmented File Transfer") {
-    const DestHandler::FsmResult& res = destHandler.stateMachine();
+    const DestHandler::FsmResult& res = destHandler.stateMachineNoPacket();
     CHECK(res.result == OK);
     std::random_device dev;
     std::mt19937 rng(dev());
@@ -202,43 +183,40 @@ TEST_CASE("CFDP Dest Handler", "[cfdp]") {
     crcCalc.add(largerFileData.begin(), largerFileData.end());
     uint32_t crc32 = crcCalc.value();
     Fss cfdpFileSize(largerFileData.size());
-    metadataPreparation(cfdpFileSize, ChecksumType::CRC_32);
+    auto metaPacket = metadataPreparation(cfdpFileSize, ChecksumType::CRC_32);
-    destHandler.stateMachine();
+    destHandler.stateMachine(metaPacket);
     metadataCheck(res, "hello.txt", "hello-cpy.txt", largerFileData.size());
-    destHandler.stateMachine();
+    destHandler.stateMachineNoPacket();
-    REQUIRE(res.callStatus == CallStatus::CALL_AFTER_DELAY);
     auto transactionId = destHandler.getTransactionId();
 
     std::vector<store_address_t> idsToCheck;
     {
       Fss offset(0);
-      FileDataInfo fdPduInfo(offset, reinterpret_cast<const uint8_t*>(largerFileData.data()),
+      FileDataInfo fdPduInfo(offset, (largerFileData.data()), largerFileData.size() / 2);
-                             largerFileData.size() / 2);
       FileDataCreator fdPduCreator(conf, fdPduInfo);
-      REQUIRE(tcStore.getFreeElement(&storeId, fdPduCreator.getSerializedSize(), &buf) == OK);
+      REQUIRE(fdPduCreator.serialize(pduBuf.data(), serLen, fdPduCreator.getSerializedSize()) ==
-      REQUIRE(fdPduCreator.serialize(buf, serLen, fdPduCreator.getSerializedSize()) == OK);
+              OK);
-      PacketInfo packetInfo(fdPduCreator.getPduType(), storeId, std::nullopt);
       idsToCheck.push_back(storeId);
-      packetInfoList.push_back(packetInfo);
+      OwnedPduPacket fdPdu(fdPduCreator.getPduType(), std::nullopt, pduBuf.data(), serLen);
+      destHandler.stateMachine(fdPdu);
     }
 
     {
       Fss offset(512);
-      FileDataInfo fdPduInfo(offset, reinterpret_cast<const uint8_t*>(largerFileData.data() + 512),
+      FileDataInfo fdPduInfo(offset, largerFileData.data() + 512, largerFileData.size() / 2);
-                             largerFileData.size() / 2);
       FileDataCreator fdPduCreator(conf, fdPduInfo);
-      REQUIRE(tcStore.getFreeElement(&storeId, fdPduCreator.getSerializedSize(), &buf) == OK);
+      REQUIRE(fdPduCreator.serialize(pduBuf.data(), serLen, fdPduCreator.getSerializedSize()) ==
-      REQUIRE(fdPduCreator.serialize(buf, serLen, fdPduCreator.getSerializedSize()) == OK);
+              OK);
-      PacketInfo packetInfo(fdPduCreator.getPduType(), storeId, std::nullopt);
       idsToCheck.push_back(storeId);
-      packetInfoList.push_back(packetInfo);
+      OwnedPduPacket fdPdu(fdPduCreator.getPduType(), std::nullopt, pduBuf.data(), serLen);
+      destHandler.stateMachine(fdPdu);
     }
 
-    destHandler.stateMachine();
+    destHandler.stateMachineNoPacket();
     fileDataPduCheck(res, idsToCheck);
-    eofPreparation(cfdpFileSize, crc32);
+    auto eofPacket = eofPreparation(cfdpFileSize, crc32);
     // After EOF, operation is done because no closure was requested
-    destHandler.stateMachine();
+    destHandler.stateMachine(eofPacket);
     eofCheck(res, transactionId);
   }
 }

unittests/cfdp/handler/testReservedMsgParser.cpp

@@ -1,3 +1,4 @@
+#include <array>
 #include <catch2/catch_test_macros.hpp>
 
 #include "fsfw/cfdp/CfdpMessage.h"

unittests/cfdp/handler/testSourceHandler.cpp

@@ -4,6 +4,7 @@
 #include <filesystem>
 #include <random>
 
+#include "cfdp/PduSenderMock.h"
 #include "fsfw/cfdp.h"
 #include "fsfw/cfdp/handler/PutRequest.h"
 #include "fsfw/cfdp/handler/SourceHandler.h"
@@ -27,13 +28,13 @@ TEST_CASE("CFDP Source Handler", "[cfdp]") {
   using namespace cfdp;
   using namespace returnvalue;
   using namespace std::filesystem;
-  const size_t MAX_FILE_SEGMENT_SIZE = 255;
+  constexpr size_t MAX_FILE_SEGMENT_SIZE = 255;
 
   MessageQueueId_t destQueueId = 2;
   AcceptsTmMock tmReceiver(destQueueId);
-  MessageQueueMock mqMock(destQueueId);
+  // MessageQueueMock mqMock(destQueueId);
-  EntityId localId = EntityId(UnsignedByteField<uint16_t>(2));
+  auto localId = EntityId(UnsignedByteField<uint16_t>(2));
-  EntityId remoteId = EntityId(UnsignedByteField<uint16_t>(5));
+  auto remoteId = EntityId(UnsignedByteField<uint16_t>(5));
   FaultHandlerMock fhMock;
   LocalEntityCfg localEntityCfg(localId, IndicationCfg(), fhMock);
   FilesystemMock fsMock;
@@ -41,49 +42,37 @@ TEST_CASE("CFDP Source Handler", "[cfdp]") {
   SeqCountProviderU16 seqCountProvider;
   SourceHandlerParams dp(localEntityCfg, userMock, seqCountProvider);
 
+  PduSenderMock pduSender;
   EventReportingProxyMock eventReporterMock;
   LocalPool::LocalPoolConfig storeCfg = {{10, 32}, {10, 64}, {10, 128}, {10, 1024}};
-  StorageManagerMock tcStore(2, storeCfg);
+  FsfwParams fp(&eventReporterMock);
-  StorageManagerMock tmStore(3, storeCfg);
+  auto sourceHandler = SourceHandler(pduSender, 4096, dp, fp);
-  FsfwParams fp(tmReceiver, &mqMock, &eventReporterMock);
-  fp.tcStore = &tcStore;
-  fp.tmStore = &tmStore;
-  auto sourceHandler = SourceHandler(dp, fp);
 
   RemoteEntityCfg cfg;
   cfg.maxFileSegmentLen = MAX_FILE_SEGMENT_SIZE;
   cfg.remoteId = remoteId;
   std::string srcFileName = "/tmp/cfdp-test.txt";
   std::string destFileName = "/tmp/cfdp-test2.txt";
-  FilesystemParams srcFileNameFs(srcFileName.c_str());
+  fsMock.createFile(srcFileName.c_str());
-  fsMock.createFile(srcFileNameFs);
+  cfdp::StringLv srcNameLv(srcFileName.c_str(), srcFileName.length());
-  cfdp::StringLv srcNameLv(srcFileNameFs.path, std::strlen(srcFileNameFs.path));
   FilesystemParams destFileNameFs(destFileName.c_str());
   cfdp::StringLv destNameLv(destFileNameFs.path, std::strlen(destFileNameFs.path));
   PutRequest putRequest(remoteId, srcNameLv, destNameLv);
   CHECK(sourceHandler.initialize() == OK);
 
-  auto onePduSentCheck = [&](const SourceHandler::FsmResult& fsmResult, TmTcMessage& tmtcMessage,
+  auto onePduSentCheck = [&](const SourceHandler::FsmResult& fsmResult) {
-                             const uint8_t** pduPtr) {
     CHECK(fsmResult.errors == 0);
     CHECK(fsmResult.packetsSent == 1);
-    CHECK(mqMock.numberOfSentMessages() == 1);
-    REQUIRE(mqMock.getNextSentMessage(destQueueId, tmtcMessage) == OK);
-    auto accessor = tmStore.getData(tmtcMessage.getStorageId());
-    REQUIRE(accessor.first == OK);
-    *pduPtr = accessor.second.data();
-    return std::move(accessor);
   };
   auto genericMetadataCheck = [&](const SourceHandler::FsmResult& fsmResult,
                                   size_t expectedFileSize, uint16_t expectedSeqNum) {
     CHECK(fsmResult.errors == 0);
-    CHECK(fsmResult.callStatus == CallStatus::CALL_AGAIN);
+    auto optNextPacket = pduSender.getNextSentPacket();
-    TmTcMessage tmtcMessage;
+    CHECK(optNextPacket.has_value());
-    const uint8_t* pduPtr;
+    const auto& [pduType, fileDirective, rawPdu] = *optNextPacket;
-    auto accessor = onePduSentCheck(fsmResult, tmtcMessage, &pduPtr);
+    CHECK(rawPdu.size() == 55);
-    CHECK(accessor.second.size() == 55);
     MetadataGenericInfo metadataInfo;
-    MetadataPduReader metadataReader(pduPtr, accessor.second.size(), metadataInfo, nullptr, 0);
+    MetadataPduReader metadataReader(rawPdu.data(), rawPdu.size(), metadataInfo, nullptr, 0);
     REQUIRE(metadataReader.parseData() == OK);
     std::string srcNameRead = metadataReader.getSourceFileName().getString();
     CHECK(srcNameRead == srcFileName);
@@ -107,20 +96,19 @@ TEST_CASE("CFDP Source Handler", "[cfdp]") {
     }
     CHECK(metadataInfo.getFileSize().value() == expectedFileSize);
     CHECK(!metadataInfo.isClosureRequested());
-    mqMock.clearMessages();
   };
   auto genericEofCheck = [&](const SourceHandler::FsmResult& fsmResult, size_t expectedFileSize,
                              uint32_t expectedChecksum, uint16_t expectedSeqNum) {
-    CHECK(fsmResult.errors == 0);
+    onePduSentCheck(fsmResult);
-    CHECK(fsmResult.callStatus == CallStatus::CALL_AGAIN);
     TmTcMessage tmtcMessage;
-    const uint8_t* pduPtr;
+    auto optNextPacket = pduSender.getNextSentPacket();
-    auto accessor = onePduSentCheck(fsmResult, tmtcMessage, &pduPtr);
+    CHECK(optNextPacket.has_value());
+    const auto& [pduType, fileDirective, rawPdu] = *optNextPacket;
     // 10 byte PDU header, 1 byte directive field, 1 byte condition code, 4 byte checksum,
     // 4 byte FSS
-    CHECK(accessor.second.size() == 20);
+    CHECK(rawPdu.size() == 20);
     EofInfo eofInfo;
-    EofPduReader eofReader(pduPtr, accessor.second.size(), eofInfo);
+    EofPduReader eofReader(rawPdu.data(), rawPdu.size(), eofInfo);
     REQUIRE(eofReader.parseData() == OK);
     TransactionSeqNum seqNum;
     eofReader.getTransactionSeqNum(seqNum);
@@ -133,8 +121,7 @@ TEST_CASE("CFDP Source Handler", "[cfdp]") {
     CHECK(eofInfo.getFileSize().value() == expectedFileSize);
   };
   auto genericNoticeOfCompletionCheck = [&](const SourceHandler::FsmResult& fsmResult,
-                                            uint16_t expectedSeqNum) {
+                                            const uint16_t expectedSeqNum) {
-    CHECK(fsmResult.callStatus == CallStatus::DONE);
     CHECK(userMock.finishedRecvd.size() == 1);
     CHECK(userMock.finishedRecvd.back().first ==
           TransactionId(localId, TransactionSeqNum(cfdp::WidthInBytes::TWO_BYTES, expectedSeqNum)));
@@ -151,41 +138,43 @@ TEST_CASE("CFDP Source Handler", "[cfdp]") {
     CHECK(sourceHandler.transactionStart(putRequest, cfg) == OK);
 
     size_t expectedFileSize = 0;
-    const SourceHandler::FsmResult& fsmResult = sourceHandler.stateMachine();
+    const SourceHandler::FsmResult& fsmResult = sourceHandler.stateMachineNoPacket();
     // Verify metadata PDU was sent.
     genericMetadataCheck(fsmResult, expectedFileSize, 0);
 
-    sourceHandler.stateMachine();
+    sourceHandler.stateMachineNoPacket();
     // Verify EOF PDU was sent. No file data PDU is sent for an empty file and the checksum is 0.
     genericEofCheck(fsmResult, expectedFileSize, 0, 0);
 
     // Verify notice of completion.
-    sourceHandler.stateMachine();
+    sourceHandler.stateMachineNoPacket();
     genericNoticeOfCompletionCheck(fsmResult, 0);
   }
 
   SECTION("Transfer small file") {
     uint16_t expectedSeqNum = 0;
-    fsMock.createFile(srcFileNameFs);
+    fsMock.createFile(srcFileName.c_str());
     std::string fileContent = "hello world\n";
     size_t expectedFileSize = fileContent.size();
-    FileOpParams params(srcFileName.c_str(), expectedFileSize);
+    fsMock.writeToFile(srcFileName.c_str(), 0, reinterpret_cast<const uint8_t*>(fileContent.data()),
-    fsMock.writeToFile(params, reinterpret_cast<const uint8_t*>(fileContent.data()));
+                       expectedFileSize);
     CHECK(sourceHandler.transactionStart(putRequest, cfg) == OK);
-    const SourceHandler::FsmResult& fsmResult = sourceHandler.stateMachine();
+    const SourceHandler::FsmResult& fsmResult = sourceHandler.stateMachineNoPacket();
 
     // Verify metadata PDU was sent.
     genericMetadataCheck(fsmResult, expectedFileSize, expectedSeqNum);
 
     // Verify that a small file data PDU was sent.
-    sourceHandler.stateMachine();
+    sourceHandler.stateMachineNoPacket();
-    TmTcMessage tmtcMessage;
+
-    const uint8_t* pduPtr;
+    onePduSentCheck(fsmResult);
-    auto accessor = onePduSentCheck(fsmResult, tmtcMessage, &pduPtr);
+    auto optNextPacket = pduSender.getNextSentPacket();
+    CHECK(optNextPacket.has_value());
+    const auto& [pduType, fileDirective, rawPdu] = *optNextPacket;
     FileDataInfo fdInfo;
-    FileDataReader fdReader(pduPtr, accessor.second.size(), fdInfo);
+    FileDataReader fdReader(rawPdu.data(), rawPdu.size(), fdInfo);
     // 10 byte PDU header, 4 byte offset, 12 bytes file data.
-    CHECK(accessor.second.size() == 26);
+    CHECK(rawPdu.size() == 26);
     CHECK(fdReader.parseData() == OK);
     CHECK(fdInfo.getOffset().value() == 0);
     size_t fileSize = 0;
@@ -194,9 +183,8 @@ TEST_CASE("CFDP Source Handler", "[cfdp]") {
     CHECK(fileData != nullptr);
     std::string dataReadBack(reinterpret_cast<const char*>(fileData), fileSize);
     CHECK(dataReadBack == fileContent);
-    mqMock.clearMessages();
 
-    sourceHandler.stateMachine();
+    sourceHandler.stateMachineNoPacket();
 
     etl::crc32 crcCalc;
     crcCalc.add(fileContent.data(), fileContent.data() + fileContent.size());
@@ -204,7 +192,7 @@ TEST_CASE("CFDP Source Handler", "[cfdp]") {
     genericEofCheck(fsmResult, expectedFileSize, crcCalc.value(), expectedSeqNum);
 
     // Verify notice of completion.
-    sourceHandler.stateMachine();
+    sourceHandler.stateMachineNoPacket();
     genericNoticeOfCompletionCheck(fsmResult, expectedSeqNum);
   }
 
@@ -220,25 +208,26 @@ TEST_CASE("CFDP Source Handler", "[cfdp]") {
       val = distU8(rng);
     }
     size_t expectedFileSize = largerFileData.size();
-    fsMock.createFile(srcFileNameFs);
+    fsMock.createFile(srcFileName.c_str());
-    FileOpParams params(srcFileName.c_str(), expectedFileSize);
+    fsMock.writeToFile(srcFileName.c_str(), 0, largerFileData.data(), largerFileData.size());
-    fsMock.writeToFile(params, reinterpret_cast<const uint8_t*>(largerFileData.data()));
     CHECK(sourceHandler.transactionStart(putRequest, cfg) == OK);
-    const SourceHandler::FsmResult& fsmResult = sourceHandler.stateMachine();
+    const SourceHandler::FsmResult& fsmResult = sourceHandler.stateMachineNoPacket();
     // Verify metadata PDU was sent.
     genericMetadataCheck(fsmResult, expectedFileSize, expectedSeqNum);
 
     // Check first file data PDU. It should have the maximum file segment size.
-    sourceHandler.stateMachine();
+    sourceHandler.stateMachineNoPacket();
-    TmTcMessage tmtcMessage;
+
-    const uint8_t* pduPtr;
+    onePduSentCheck(fsmResult);
+    auto optNextPacket = pduSender.getNextSentPacket();
+    CHECK(optNextPacket.has_value());
+    const auto& [pduType, fileDirective, rawPdu] = *optNextPacket;
     FileDataInfo fdInfo;
     {
-      CHECK(fsmResult.callStatus == CallStatus::CALL_AGAIN);
+      // auto accessor = onePduSentCheck(fsmResult, tmtcMessage, &pduPtr);
-      auto accessor = onePduSentCheck(fsmResult, tmtcMessage, &pduPtr);
+      FileDataReader fdReader(rawPdu.data(), rawPdu.size(), fdInfo);
-      FileDataReader fdReader(pduPtr, accessor.second.size(), fdInfo);
       // 10 byte PDU header, 4 byte offset, 255 byte file data
-      CHECK(accessor.second.size() == 269);
+      CHECK(rawPdu.size() == 269);
       CHECK(fdReader.parseData() == OK);
       CHECK(fdInfo.getOffset().value() == 0);
       size_t fileSize = 0;
@@ -249,16 +238,16 @@ TEST_CASE("CFDP Source Handler", "[cfdp]") {
         CHECK(fileData[i] == largerFileData[i]);
       }
     }
-    mqMock.clearMessages();
 
     // Check second file data PDU.
-    sourceHandler.stateMachine();
+    sourceHandler.stateMachineNoPacket();
     {
-      CHECK(fsmResult.callStatus == CallStatus::CALL_AGAIN);
+      optNextPacket = pduSender.getNextSentPacket();
-      auto accessor = onePduSentCheck(fsmResult, tmtcMessage, &pduPtr);
+      CHECK(optNextPacket.has_value());
-      FileDataReader fdReader(pduPtr, accessor.second.size(), fdInfo);
+      const auto& [pduType, fileDirective, rawPdu] = *optNextPacket;
+      FileDataReader fdReader(rawPdu.data(), rawPdu.size(), fdInfo);
       // 10 byte PDU header, 4 byte offset, remaining file data (400 - 255 == 145).
-      CHECK(accessor.second.size() == 10 + 4 + largerFileData.size() - MAX_FILE_SEGMENT_SIZE);
+      CHECK(rawPdu.size() == 10 + 4 + largerFileData.size() - MAX_FILE_SEGMENT_SIZE);
       CHECK(fdReader.parseData() == OK);
       CHECK(fdInfo.getOffset().value() == MAX_FILE_SEGMENT_SIZE);
       size_t fileDataSize = 0;
@@ -269,10 +258,9 @@ TEST_CASE("CFDP Source Handler", "[cfdp]") {
         CHECK(fileData[i] == largerFileData[MAX_FILE_SEGMENT_SIZE + i]);
       }
     }
-    mqMock.clearMessages();
 
     // Check EOF and verify checksum.
-    sourceHandler.stateMachine();
+    sourceHandler.stateMachineNoPacket();
 
     etl::crc32 crcCalc;
     crcCalc.add(largerFileData.data(), largerFileData.data() + largerFileData.size());
@@ -280,7 +268,7 @@ TEST_CASE("CFDP Source Handler", "[cfdp]") {
     genericEofCheck(fsmResult, expectedFileSize, crcCalc.value(), expectedSeqNum);
 
     // Verify notice of completion.
-    sourceHandler.stateMachine();
+    sourceHandler.stateMachineNoPacket();
     genericNoticeOfCompletionCheck(fsmResult, expectedSeqNum);
   }
 }

unittests/cfdp/pdu/testCfdpHeader.cpp

@@ -4,7 +4,7 @@
 #include "fsfw/cfdp/pdu/FinishedInfo.h"
 #include "fsfw/cfdp/pdu/FinishedPduCreator.h"
 #include "fsfw/cfdp/pdu/HeaderCreator.h"
-#include "fsfw/cfdp/pdu/PduHeaderReader.h"
+#include "fsfw/cfdp/pdu/HeaderReader.h"
 #include "fsfw/returnvalues/returnvalue.h"
 
 using namespace returnvalue;

unittests/hal/testFsMock.cpp

@@ -10,7 +10,7 @@ TEST_CASE("Filesystem Mock", "[mocks]") {
 
   SECTION("Create File") {
     FilesystemParams params("hello.txt");
-    CHECK(fsMock.createFile(params) == returnvalue::OK);
+    CHECK(fsMock.createFile("hello.txt") == returnvalue::OK);
     auto iter = fsMock.fileMap.find("hello.txt");
     REQUIRE(iter != fsMock.fileMap.end());
     FilesystemMock::FileInfo &stats = iter->second;
@@ -21,8 +21,8 @@ TEST_CASE("Filesystem Mock", "[mocks]") {
   SECTION("Write to File") {
     std::string testData = "test data";
     FileOpParams params("hello.txt", testData.size());
-    CHECK(fsMock.writeToFile(params, reinterpret_cast<const uint8_t *>(testData.data())) ==
+    CHECK(fsMock.writeToFile("hello.txt", 0, reinterpret_cast<const uint8_t *>(testData.data()),
-          returnvalue::OK);
+                             testData.size()) == returnvalue::OK);
     auto iter = fsMock.fileMap.find("hello.txt");
     REQUIRE(iter != fsMock.fileMap.end());
     FilesystemMock::FileInfo &stats = iter->second;
@@ -38,7 +38,7 @@ TEST_CASE("Filesystem Mock", "[mocks]") {
 
   SECTION("Create Directory") {
     FilesystemParams params("hello");
-    CHECK(fsMock.createDirectory(params) == returnvalue::OK);
+    CHECK(fsMock.createDirectory("hello") == returnvalue::OK);
     REQUIRE(not fsMock.dirMap.empty());
     auto iter = fsMock.dirMap.find("hello");
     REQUIRE(iter != fsMock.dirMap.end());

unittests/hal/testHostFilesystem.cpp

@@ -25,15 +25,13 @@ TEST_CASE("Host Filesystem", "[hal][host]") {
   REQUIRE_NOTHROW(fs::remove_all(dir0));
 
   SECTION("Create file") {
-    FilesystemParams params(file0.c_str());
+    REQUIRE(hostFs.createFile(file0.c_str()) == returnvalue::OK);
-    REQUIRE(hostFs.createFile(params) == returnvalue::OK);
     CHECK(fs::is_regular_file(file0));
     REQUIRE(fs::exists(file0));
   }
 
   SECTION("Remove File") {
-    FilesystemParams params(file0.c_str());
+    REQUIRE(hostFs.createFile(file0.c_str()) == returnvalue::OK);
-    REQUIRE(hostFs.createFile(params) == returnvalue::OK);
     CHECK(fs::is_regular_file(file0));
     REQUIRE(fs::exists(file0));
     REQUIRE(hostFs.removeFile(file0.c_str()) == returnvalue::OK);
@@ -41,23 +39,20 @@ TEST_CASE("Host Filesystem", "[hal][host]") {
   }
 
   SECTION("Create Directory") {
-    FilesystemParams params(dir0.c_str());
+    REQUIRE(hostFs.createDirectory(dir0.c_str()) == returnvalue::OK);
-    REQUIRE(hostFs.createDirectory(params) == returnvalue::OK);
     CHECK(fs::is_directory(dir0));
     REQUIRE(fs::exists(dir0));
   }
 
   SECTION("Remove Directory") {
-    FilesystemParams params(dir0.c_str());
+    REQUIRE(hostFs.createDirectory(dir0.c_str()) == returnvalue::OK);
-    REQUIRE(hostFs.createDirectory(params) == returnvalue::OK);
     REQUIRE(fs::exists(dir0));
-    REQUIRE(hostFs.removeDirectory(params) == returnvalue::OK);
+    REQUIRE(hostFs.removeDirectory(dir0.c_str(), false, nullptr) == returnvalue::OK);
     REQUIRE(not fs::exists(dir0));
   }
 
   SECTION("Rename File") {
-    FilesystemParams params(file0.c_str());
+    REQUIRE(hostFs.createFile(file0.c_str()) == returnvalue::OK);
-    REQUIRE(hostFs.createFile(params) == returnvalue::OK);
     CHECK(fs::is_regular_file(file0));
     REQUIRE(fs::exists(file0));
     REQUIRE(hostFs.rename(file0.c_str(), file1.c_str()) == returnvalue::OK);
@@ -65,12 +60,11 @@ TEST_CASE("Host Filesystem", "[hal][host]") {
 
   SECTION("Write To File") {
     std::string data = "hello world!";
-    FileOpParams params(file0.c_str(), data.size());
+    REQUIRE(hostFs.createFile(file0.c_str()) == returnvalue::OK);
-    REQUIRE(hostFs.createFile(params.fsParams) == returnvalue::OK);
     CHECK(fs::is_regular_file(file0));
     REQUIRE(fs::exists(file0));
-    CHECK(hostFs.writeToFile(params, reinterpret_cast<const uint8_t*>(data.c_str())) ==
+    CHECK(hostFs.writeToFile(file0.c_str(), 0, reinterpret_cast<const uint8_t*>(data.c_str()),
-          returnvalue::OK);
+                             data.size()) == returnvalue::OK);
     CHECK(fs::file_size(file0) == data.size());
     ifstream ifile(file0);
     std::array<char, 524> readBuf{};
@@ -87,14 +81,13 @@ TEST_CASE("Host Filesystem", "[hal][host]") {
     for (uint8_t& byte : randData) {
       byte = distU8(rng);
     }
-    FileOpParams params(file0.c_str(), randData.size() - 256);
+    REQUIRE(hostFs.createFile(file0.c_str()) == returnvalue::OK);
-    REQUIRE(hostFs.createFile(params.fsParams) == returnvalue::OK);
     CHECK(fs::is_regular_file(file0));
     REQUIRE(fs::exists(file0));
     // Write first file chunk
-    CHECK(hostFs.writeToFile(params, randData.cbegin()) == returnvalue::OK);
+    CHECK(hostFs.writeToFile(file0.c_str(), 0, randData.cbegin(), randData.size() - 256) ==
-    params.offset = 256;
+          returnvalue::OK);
-    CHECK(hostFs.writeToFile(params, randData.cbegin() + 256) == returnvalue::OK);
+    CHECK(hostFs.writeToFile(file0.c_str(), 256, randData.cbegin() + 256, 256) == returnvalue::OK);
     std::ifstream rf(file0, ios::binary);
     std::array<uint8_t, 512> readBack{};
     REQUIRE(std::filesystem::file_size(file0) == 512);
@@ -106,8 +99,7 @@ TEST_CASE("Host Filesystem", "[hal][host]") {
 
   SECTION("Read From File") {
     std::string data = "hello world!";
-    FileOpParams params(file0.c_str(), data.size());
+    REQUIRE(hostFs.createFile(file0.c_str()) == returnvalue::OK);
-    REQUIRE(hostFs.createFile(params.fsParams) == returnvalue::OK);
     CHECK(fs::is_regular_file(file0));
     ofstream of(file0);
     of.write(data.c_str(), static_cast<unsigned int>(data.size()));
@@ -116,8 +108,10 @@ TEST_CASE("Host Filesystem", "[hal][host]") {
     REQUIRE(fs::exists(file0));
     std::array<uint8_t, 256> readBuf{};
     uint8_t* readPtr = readBuf.data();
-    size_t readSize = 0;
+    size_t readSize = data.size();
-    CHECK(hostFs.readFromFile(params, &readPtr, readSize, readBuf.size()) == returnvalue::OK);
+    size_t actuallyRead = 0;
+    CHECK(hostFs.readFromFile(file0.c_str(), 0, readSize, readPtr, actuallyRead, readBuf.size()) ==
+          returnvalue::OK);
     std::string readBackString(reinterpret_cast<const char*>(readBuf.data()));
     CHECK(readSize == data.size());
     CHECK(data == readBackString);
@@ -125,21 +119,21 @@ TEST_CASE("Host Filesystem", "[hal][host]") {
 
   SECTION("Invalid Input does not crash") {
     FileOpParams params(nullptr, 10);
-    REQUIRE(hostFs.createFile(params.fsParams) != returnvalue::OK);
+    REQUIRE(hostFs.createFile(nullptr) != returnvalue::OK);
-    REQUIRE(hostFs.createDirectory(params.fsParams) != returnvalue::OK);
+    REQUIRE(hostFs.createDirectory(nullptr) != returnvalue::OK);
-    REQUIRE(hostFs.createFile(params.fsParams) != returnvalue::OK);
+    REQUIRE(hostFs.createFile(nullptr) != returnvalue::OK);
-    REQUIRE(hostFs.removeDirectory(params.fsParams) != returnvalue::OK);
+    REQUIRE(hostFs.removeDirectory(nullptr, false, nullptr) != returnvalue::OK);
     REQUIRE(hostFs.removeFile(nullptr) != returnvalue::OK);
     REQUIRE(hostFs.rename(nullptr, nullptr) != returnvalue::OK);
-    REQUIRE(hostFs.writeToFile(params, nullptr) != returnvalue::OK);
+    REQUIRE(hostFs.writeToFile(nullptr, 0, nullptr, 0) != returnvalue::OK);
     size_t readLen = 0;
-    REQUIRE(hostFs.readFromFile(params, nullptr, readLen, 20) != returnvalue::OK);
+    REQUIRE(hostFs.readFromFile(nullptr, 0, 0, nullptr, readLen, 20) != returnvalue::OK);
   }
 
   SECTION("Create File but already exists") {
     FilesystemParams params(file0.c_str());
-    REQUIRE(hostFs.createFile(params) == returnvalue::OK);
+    REQUIRE(hostFs.createFile(file0.c_str()) == returnvalue::OK);
-    REQUIRE(hostFs.createFile(params) == HasFileSystemIF::FILE_ALREADY_EXISTS);
+    REQUIRE(hostFs.createFile(file0.c_str()) == HasFileSystemIF::FILE_ALREADY_EXISTS);
   }
 
   SECTION("Remove File but does not exist") {
@@ -148,36 +142,35 @@ TEST_CASE("Host Filesystem", "[hal][host]") {
 
   SECTION("Create Directory but already exists") {
     FileOpParams params(file0.c_str(), 12);
-    REQUIRE(hostFs.createDirectory(params.fsParams) == returnvalue::OK);
+    REQUIRE(hostFs.createDirectory(file0.c_str()) == returnvalue::OK);
-    REQUIRE(hostFs.createDirectory(params.fsParams) == HasFileSystemIF::DIRECTORY_ALREADY_EXISTS);
+    REQUIRE(hostFs.createDirectory(file0.c_str()) == HasFileSystemIF::DIRECTORY_ALREADY_EXISTS);
   }
 
   SECTION("Remove Directory but does not exist") {
     FilesystemParams params(dir0.c_str());
-    REQUIRE(hostFs.removeDirectory(params) == HasFileSystemIF::DIRECTORY_DOES_NOT_EXIST);
+    REQUIRE(hostFs.removeDirectory(dir0.c_str(), false, nullptr) ==
+            HasFileSystemIF::DIRECTORY_DOES_NOT_EXIST);
   }
 
   SECTION("Remove Directory but is file") {
     ofstream of(file0);
-    FilesystemParams params(file0.c_str());
+    REQUIRE(hostFs.removeDirectory(file0.c_str(), false, nullptr) ==
-    REQUIRE(hostFs.removeDirectory(params) == HasFileSystemIF::NOT_A_DIRECTORY);
+            HasFileSystemIF::NOT_A_DIRECTORY);
   }
 
   SECTION("Read from file but does not exist") {
     std::string data = "hello world!";
-    FileOpParams params(file0.c_str(), data.size());
+    std::array<uint8_t, 16> readBuf{};
-    std::array<uint8_t, 10> readBuf{};
     uint8_t* readPtr = readBuf.data();
     size_t readSize = 0;
-    CHECK(hostFs.readFromFile(params, &readPtr, readSize, readBuf.size()) ==
+    CHECK(hostFs.readFromFile(file0.c_str(), 0, data.size(), readPtr, readSize, readBuf.size()) ==
           HasFileSystemIF::FILE_DOES_NOT_EXIST);
   }
 
   SECTION("Write to file but does not exist") {
     std::string data = "hello world!";
-    FileOpParams params(file0.c_str(), data.size());
+    CHECK(hostFs.writeToFile(file0.c_str(), 0, reinterpret_cast<const uint8_t*>(data.c_str()),
-    CHECK(hostFs.writeToFile(params, reinterpret_cast<const uint8_t*>(data.c_str())) ==
+                             data.size()) == HasFileSystemIF::FILE_DOES_NOT_EXIST);
-          HasFileSystemIF::FILE_DOES_NOT_EXIST);
   }
 
   SECTION("Remove recursively") {
@@ -185,7 +178,7 @@ TEST_CASE("Host Filesystem", "[hal][host]") {
     ofstream of(fileInDir0);
     CHECK(fs::is_directory(dir0));
     CHECK(fs::is_regular_file(fileInDir0));
-    REQUIRE(hostFs.removeDirectory(FilesystemParams(dir0.c_str()), true) == returnvalue::OK);
+    REQUIRE(hostFs.removeDirectory(dir0.c_str(), true, nullptr) == returnvalue::OK);
     CHECK(not fs::is_directory(dir0));
     CHECK(not fs::is_regular_file(fileInDir0));
   }
@@ -195,12 +188,12 @@ TEST_CASE("Host Filesystem", "[hal][host]") {
     ofstream of(fileInDir0);
     CHECK(fs::is_directory(dir0));
     CHECK(fs::is_regular_file(fileInDir0));
-    REQUIRE(hostFs.removeDirectory(FilesystemParams(dir0.c_str())) ==
+    REQUIRE(hostFs.removeDirectory(dir0.c_str(), false, nullptr) ==
             HasFileSystemIF::DIRECTORY_NOT_EMPTY);
   }
 
   SECTION("Create directory with parent directory") {
-    CHECK(hostFs.createDirectory(FilesystemParams(dirWithParent.c_str()), true) == returnvalue::OK);
+    CHECK(hostFs.createDirectory(dirWithParent.c_str(), true, nullptr) == returnvalue::OK);
     CHECK(fs::is_directory(dir0));
     CHECK(fs::is_directory(dirWithParent));
   }
@@ -216,10 +209,9 @@ TEST_CASE("Host Filesystem", "[hal][host]") {
     std::array<uint8_t, 15> readBuf{};
     uint8_t* readPtr = readBuf.data();
     size_t readSize = 0;
-    CHECK(hostFs.readFromFile(params, &readPtr, readSize, 5) == SerializeIF::BUFFER_TOO_SHORT);
+    CHECK(hostFs.readFromFile(file0.c_str(), 0, data.size(), readPtr, readSize, 5) ==
-    readSize = 10;
-    CHECK(hostFs.readFromFile(params, &readPtr, readSize, readBuf.size()) ==
           SerializeIF::BUFFER_TOO_SHORT);
+    ;
   }
 
   REQUIRE_NOTHROW(fs::remove(file0));

unittests/mocks/DeviceHandlerMock.cpp

@@ -4,9 +4,7 @@
 
 DeviceHandlerMock::DeviceHandlerMock(object_id_t objectId, object_id_t deviceCommunication,
                                      CookieIF *comCookie, FailureIsolationBase *fdirInstance)
-    : DeviceHandlerBase(objectId, deviceCommunication, comCookie, fdirInstance) {
+    : DeviceHandlerBase(objectId, deviceCommunication, comCookie, fdirInstance) {}
-  setMode(MODE_ON);
-}
 
 DeviceHandlerMock::~DeviceHandlerMock() = default;
 
@@ -101,3 +99,12 @@ ReturnValue_t DeviceHandlerMock::enablePeriodicReply(DeviceCommandId_t replyId)
 ReturnValue_t DeviceHandlerMock::disablePeriodicReply(DeviceCommandId_t replyId) {
   return updatePeriodicReply(false, replyId);
 }
+
+ReturnValue_t DeviceHandlerMock::initialize() {
+  ReturnValue_t result = DeviceHandlerBase::initialize();
+  if (result != returnvalue::OK) {
+    return result;
+  }
+  setMode(MODE_ON);
+  return result;
+}

unittests/mocks/DeviceHandlerMock.h

@@ -21,6 +21,8 @@ class DeviceHandlerMock : public DeviceHandlerBase {
   ReturnValue_t enablePeriodicReply(DeviceCommandId_t replyId);
   ReturnValue_t disablePeriodicReply(DeviceCommandId_t replyId);
 
+  ReturnValue_t initialize() override;
+
  protected:
   void doStartUp() override;
   void doShutDown() override;

unittests/mocks/FilesystemMock.cpp

@@ -1,5 +1,6 @@
 #include "FilesystemMock.h"
 
+#include <cstring>
 #include <filesystem>
 
 #include "fsfw/serialize/SerializeIF.h"
@@ -12,45 +13,42 @@ ReturnValue_t FilesystemMock::feedFile(const std::string &filename, std::ifstrea
   FileOpParams params(filename.c_str(), fileSize);
   std::vector<uint8_t> rawData(fileSize);
   file.read(reinterpret_cast<char*>(rawData.data()), static_cast<unsigned int>(rawData.size()));
-  createOrAddToFile(params, rawData.data());
+  createOrAddToFile(filename.data(), 0, rawData.data(), rawData.size());
   return returnvalue::OK;
 }
 
-ReturnValue_t FilesystemMock::writeToFile(FileOpParams params, const uint8_t *data) {
+ReturnValue_t FilesystemMock::writeToFile(const char* path, size_t offset, const uint8_t* data,
-  createOrAddToFile(params, data);
+                                          size_t size) {
+  createOrAddToFile(path, offset, data, size);
   return returnvalue::OK;
 }
 
-ReturnValue_t FilesystemMock::readFromFile(FileOpParams params, uint8_t **buffer, size_t &readSize,
+ReturnValue_t FilesystemMock::readFromFile(const char* path, size_t offset, size_t size,
-                                           size_t maxSize) {
+                                           uint8_t* buffer, size_t& readSize, size_t maxSize) {
-  std::string filename(params.path());
+  const std::string filename(path);
-  auto iter = fileMap.find(filename);
+  const auto iter = fileMap.find(filename);
   if (iter == fileMap.end()) {
     return HasFileSystemIF::FILE_DOES_NOT_EXIST;
-  } else {
+  }
-    FileInfo &info = iter->second;
+  auto& [fileSegQueue, fileRaw] = iter->second;
-    size_t readLen = params.size;
+  size_t readLen = size;
-    if (params.offset + params.size > info.fileRaw.size()) {
+  if (offset + size > fileRaw.size()) {
-      if (params.offset > info.fileRaw.size()) {
+    if (offset > fileRaw.size()) {
       return returnvalue::OK;
     }
-      readLen = info.fileRaw.size() - params.offset;
+    readLen = fileRaw.size() - offset;
   }
   if (readSize + readLen > maxSize) {
     return SerializeIF::STREAM_TOO_SHORT;
   }
-    std::copy(info.fileRaw.data() + params.offset, info.fileRaw.data() + params.offset + readLen,
+  // std::copy(info.fileRaw.data() + offset, info.fileRaw.data() + offset + readLen, *buffer);
-              *buffer);
+  std::memcpy(buffer, fileRaw.data() + offset, readLen);
-    *buffer += readLen;
+  readSize = readLen;
-    readSize += readLen;
-  }
   return returnvalue::OK;
 }
 
-ReturnValue_t FilesystemMock::createFile(FilesystemParams params, const uint8_t *data,
+ReturnValue_t FilesystemMock::createFile(const char* path, const uint8_t* data, size_t size) {
-                                         size_t size) {
+  createOrAddToFile(path, 0, data, size);
-  FileOpParams params2(params.path, size);
-  createOrAddToFile(params2, data);
   return returnvalue::OK;
 }
 
@@ -65,15 +63,17 @@ ReturnValue_t FilesystemMock::removeFile(const char *path, FileSystemArgsIF *arg
   }
 }
 
-ReturnValue_t FilesystemMock::createDirectory(FilesystemParams params, bool createParentDirs) {
+ReturnValue_t FilesystemMock::createDirectory(const char* path, bool createParentDirs,
-  std::string dirPath = params.path;
+                                              FileSystemArgsIF* args) {
+  std::string dirPath = path;
   dirMap[dirPath].createCallCount++;
   dirMap[dirPath].wihParentDir.push(createParentDirs);
   return returnvalue::OK;
 }
 
-ReturnValue_t FilesystemMock::removeDirectory(FilesystemParams params, bool deleteRecurively) {
+ReturnValue_t FilesystemMock::removeDirectory(const char* path, bool deleteRecurively,
-  std::string dirPath = params.path;
+                                              FileSystemArgsIF* args) {
+  std::string dirPath = path;
   dirMap[dirPath].delCallCount++;
   dirMap[dirPath].recursiveDeletion.push(deleteRecurively);
   return returnvalue::OK;
@@ -85,36 +85,36 @@ ReturnValue_t FilesystemMock::rename(const char *oldPath, const char *newPath,
   return returnvalue::OK;
 }
 
-void FilesystemMock::createOrAddToFile(FileOpParams params, const uint8_t *data) {
+void FilesystemMock::createOrAddToFile(const char* path, size_t offset, const uint8_t* data,
-  std::string filename(params.path());
+                                       size_t dataSize) {
+  std::string filename(path);
   auto iter = fileMap.find(filename);
   if (iter == fileMap.end()) {
     FileSegmentQueue queue;
-    if (params.size > 0) {
+    if (dataSize > 0) {
-      queue.emplace(filename, params.offset, data, params.size);
+      queue.emplace(filename, offset, data, dataSize);
     }
     FileInfo info;
     info.fileSegQueue = queue;
     if (data != nullptr) {
-      info.fileRaw.insert(info.fileRaw.end(), data, data + params.size);
+      info.fileRaw.insert(info.fileRaw.end(), data, data + dataSize);
     }
     fileMap.emplace(filename, info);
   } else {
     FileInfo& info = iter->second;
-    info.fileSegQueue.emplace(filename, params.offset, data, params.size);
+    info.fileSegQueue.emplace(filename, offset, data, dataSize);
     if (data == nullptr) {
       return;
     }
     // Easiest case: append data to the end
-    if (params.offset == info.fileRaw.size()) {
+    if (offset == info.fileRaw.size()) {
-      info.fileRaw.insert(info.fileRaw.end(), data, data + params.size);
+      info.fileRaw.insert(info.fileRaw.end(), data, data + dataSize);
     } else {
-      size_t totalNewLen = params.offset + params.size;
+      size_t totalNewLen = offset + dataSize;
       if (totalNewLen > info.fileRaw.size()) {
-        info.fileRaw.resize(params.offset + params.size);
+        info.fileRaw.resize(offset + dataSize);
       }
-      std::copy(data, data + params.size,
+      std::copy(data, data + dataSize, info.fileRaw.begin() + static_cast<unsigned int>(offset));
-                info.fileRaw.begin() + static_cast<unsigned int>(params.offset));
     }
   }
 }
@@ -126,8 +126,8 @@ void FilesystemMock::reset() {
   std::swap(renameQueue, empty);
 }
 
-bool FilesystemMock::fileExists(FilesystemParams params) {
+bool FilesystemMock::fileExists(const char* path, FileSystemArgsIF* args) {
-  std::string filename(params.path);
+  std::string filename(path);
   auto iter = fileMap.find(filename);
   if (iter == fileMap.end()) {
     return false;
@@ -135,20 +135,21 @@ bool FilesystemMock::fileExists(FilesystemParams params) {
   return true;
 }
 
-ReturnValue_t FilesystemMock::truncateFile(FilesystemParams params) {
+ReturnValue_t FilesystemMock::truncateFile(const char* path, FileSystemArgsIF* args) {
-  truncateCalledOnFile = params.path;
+  truncateCalledOnFile = path;
   return returnvalue::OK;
 }
 
-ReturnValue_t FilesystemMock::getBaseFilename(FilesystemParams params, char *nameBuf, size_t maxLen,
+ReturnValue_t FilesystemMock::getBaseFilename(const char* path, char* nameBuf, size_t maxLen,
                                               size_t& baseNameLen) {
   return returnvalue::OK;
 }
 
-bool FilesystemMock::isDirectory(const char *path) { return false; }
+ReturnValue_t FilesystemMock::isDirectory(const char* path, bool& isDirectory) { return false; }
 
-bool FilesystemMock::getFileSize(FilesystemParams params, size_t &fileSize) {
+ReturnValue_t FilesystemMock::getFileSize(const char* path, uint64_t& fileSize,
-  std::string filename(params.path);
+                                          FileSystemArgsIF* args) {
+  std::string filename(path);
   auto iter = fileMap.find(filename);
   if (iter != fileMap.end()) {
     fileSize = iter->second.fileRaw.size();

unittests/mocks/FilesystemMock.h

@@ -56,21 +56,31 @@ class FilesystemMock : public HasFileSystemIF {
   std::string truncateCalledOnFile;
   ReturnValue_t feedFile(const std::string& filename, std::ifstream& file);
 
-  ReturnValue_t getBaseFilename(FilesystemParams params, char *nameBuf, size_t maxLen,
+  ReturnValue_t getBaseFilename(const char* path, char* nameBuf, size_t maxLen,
                                 size_t& baseNameLen) override;
 
-  bool isDirectory(const char *path) override;
+  ReturnValue_t isDirectory(const char* path, bool& isDirectory) override;
-  bool fileExists(FilesystemParams params) override;
-  ReturnValue_t truncateFile(FilesystemParams params) override;
-  bool getFileSize(FilesystemParams params, size_t &fileSize) override;
 
-  ReturnValue_t writeToFile(FileOpParams params, const uint8_t *data) override;
+  bool fileExists(const char* path, FileSystemArgsIF* args) override;
-  ReturnValue_t readFromFile(FileOpParams params, uint8_t **buffer, size_t &readSize,
+
-                             size_t maxSize) override;
+  ReturnValue_t truncateFile(const char* path, FileSystemArgsIF* args) override;
-  ReturnValue_t createFile(FilesystemParams params, const uint8_t *data, size_t size) override;
+
+  ReturnValue_t getFileSize(const char* path, uint64_t& fileSize, FileSystemArgsIF* args) override;
+
+  ReturnValue_t writeToFile(const char* path, size_t offset, const uint8_t* data,
+                            size_t size) override;
+
+  ReturnValue_t readFromFile(const char* path, size_t offset, size_t size, uint8_t* buffer,
+                             size_t& readSize, size_t maxSize) override;
+
+  ReturnValue_t createFile(const char* path, const uint8_t* data, size_t size) override;
   ReturnValue_t removeFile(const char* path, FileSystemArgsIF* args) override;
-  ReturnValue_t createDirectory(FilesystemParams params, bool createParentDirs) override;
+
-  ReturnValue_t removeDirectory(FilesystemParams params, bool deleteRecurively) override;
+  ReturnValue_t createDirectory(const char* path, bool createParentDirs,
+                                FileSystemArgsIF* args) override;
+
+  ReturnValue_t removeDirectory(const char* path, bool deleteRecurively,
+                                FileSystemArgsIF* args) override;
   ReturnValue_t rename(const char* oldPath, const char* newPath, FileSystemArgsIF* args) override;
 
   void reset();
@@ -80,7 +90,7 @@ class FilesystemMock : public HasFileSystemIF {
   using HasFileSystemIF::readFromFile;
 
  private:
-  void createOrAddToFile(FileOpParams params, const uint8_t *data);
+  void createOrAddToFile(const char* path, size_t offset, const uint8_t* data, size_t dataSize);
 };
 
 #endif  // FSFW_MOCKS_FILESYSTEMMOCK_H

unittests/tmtcpacket/testCcsdsCreator.cpp

@@ -82,13 +82,15 @@ TEST_CASE("CCSDS Creator", "[ccsds-creator]") {
     CHECK(buf[5] == 0xFF);
   }
 
-  SECTION("Setting data length 0 is ignored") {
+  SECTION("Setting data length 0") {
     SpacePacketCreator creator = SpacePacketCreator(
         ccsds::PacketType::TC, true, 0xFFFF, ccsds::SequenceFlags::FIRST_SEGMENT, 0x34, 0x22);
     creator.setCcsdsLenFromTotalDataFieldLen(0);
-    REQUIRE(creator.getPacketDataLen() == 0x22);
+    // Will result in field length 0.
+    REQUIRE(creator.getPacketDataLen() == 0);
+    // Will also result in field length 0.
     creator.setCcsdsLenFromTotalDataFieldLen(1);
-    REQUIRE(creator.getPacketDataLen() == 0x00);
+    REQUIRE(creator.getPacketDataLen() == 0);
   }
 
   SECTION("Invalid APID") {