linux/CMakeLists.txt

@@ -10,3 +10,4 @@ target_sources(${LIB_FSFW_HAL_NAME} PRIVATE
 add_subdirectory(gpio)
 add_subdirectory(spi)
 add_subdirectory(i2c)
+add_subdirectory(uart)

linux/spi/SpiComIF.cpp

@@ -2,7 +2,7 @@
 #include "SpiCookie.h"
 #include "../utility.h"
 #include "../UnixFileGuard.h"
-#include <FSFWConfig.h>
+#include "FSFWConfig.h"
 
 #include <fsfw/ipc/MutexFactory.h>
 #include <fsfw/globalfunctions/arrayprinter.h>
@@ -17,11 +17,11 @@
 
 /* Can be used for low-level debugging of the SPI bus */
 #ifndef FSFW_HAL_LINUX_SPI_WIRETAPPING
-#define FSFW_HAL_LINUX_SPI_WIRETAPPING                  1
+#define FSFW_HAL_LINUX_SPI_WIRETAPPING                  0
 #endif
 
-SpiComIF::SpiComIF(object_id_t objectId, GpioIF* gpioComIF): SystemObject(objectId),
-        gpioComIF(gpioComIF) {
+SpiComIF::SpiComIF(object_id_t objectId, GpioIF* gpioComIF):
+        SystemObject(objectId), gpioComIF(gpioComIF) {
     if(gpioComIF == nullptr) {
 #if FSFW_VERBOSE_LEVEL >= 1
 #if FSFW_CPP_OSTREAM_ENABLED == 1
@@ -138,7 +138,6 @@ ReturnValue_t SpiComIF::initializeInterface(CookieIF *cookie) {
 ReturnValue_t SpiComIF::sendMessage(CookieIF *cookie, const uint8_t *sendData, size_t sendLen) {
     SpiCookie* spiCookie = dynamic_cast<SpiCookie*>(cookie);
     ReturnValue_t result = HasReturnvaluesIF::RETURN_OK;
-    int retval = 0;
 
     if(spiCookie == nullptr) {
         return NULLPOINTER;
@@ -158,12 +157,34 @@ ReturnValue_t SpiComIF::sendMessage(CookieIF *cookie, const uint8_t *sendData, s
         return DeviceCommunicationIF::TOO_MUCH_DATA;
     }
 
+    if(spiCookie->getComIfMode() == spi::SpiComIfModes::REGULAR) {
+        result = performRegularSendOperation(spiCookie, sendData, sendLen);
+    }
+    else if(spiCookie->getComIfMode() == spi::SpiComIfModes::CALLBACK) {
+        spi::send_callback_function_t sendFunc = nullptr;
+        void* funcArgs = nullptr;
+        spiCookie->getCallback(&sendFunc, &funcArgs);
+        if(sendFunc != nullptr) {
+            result = sendFunc(this, spiCookie, sendData, sendLen, funcArgs);
+        }
+    }
+    return result;
+}
 
+ReturnValue_t SpiComIF::performRegularSendOperation(SpiCookie *spiCookie, const uint8_t *sendData,
+        size_t sendLen) {
+    address_t spiAddress = spiCookie->getSpiAddress();
+    auto iter = spiDeviceMap.find(spiAddress);
+    if(iter != spiDeviceMap.end()) {
+        spiCookie->assignReadBuffer(iter->second.replyBuffer.data());
+    }
+
+    ReturnValue_t result = HasReturnvaluesIF::RETURN_OK;
+    int retval = 0;
     /* Prepare transfer */
     int fileDescriptor = 0;
     std::string device = spiCookie->getSpiDevice();
-    UnixFileGuard fileHelper(device, &fileDescriptor, O_RDWR,
-            "SpiComIF::sendMessage: ");
+    UnixFileGuard fileHelper(device, &fileDescriptor, O_RDWR, "SpiComIF::sendMessage: ");
     if(fileHelper.getOpenResult() != HasReturnvaluesIF::RETURN_OK) {
         return OPENING_FILE_FAILED;
     }
@@ -198,19 +219,7 @@ ReturnValue_t SpiComIF::sendMessage(CookieIF *cookie, const uint8_t *sendData, s
             result = FULL_DUPLEX_TRANSFER_FAILED;
         }
 #if FSFW_HAL_LINUX_SPI_WIRETAPPING == 1
-        size_t dataLen = spiCookie->getTransferStructHandle()->len;
-        uint8_t* dataPtr = reinterpret_cast<uint8_t*>(spiCookie->getTransferStructHandle()->tx_buf);
-#if FSFW_CPP_OSTREAM_ENABLED == 1
-        sif::info << "Sent SPI data: " << std::endl;
-        arrayprinter::print(dataPtr, dataLen, OutputType::HEX, false);
-        sif::info << "Received SPI data: " << std::endl;
-#else
-        sif::printInfo("Sent SPI data: \n");
-        arrayprinter::print(dataPtr, dataLen, OutputType::HEX, false);
-        sif::printInfo("Received SPI data: \n");
-#endif /* FSFW_CPP_OSTREAM_ENABLED == 1 */
-        dataPtr = reinterpret_cast<uint8_t*>(spiCookie->getTransferStructHandle()->rx_buf);
-        arrayprinter::print(dataPtr, dataLen, OutputType::HEX, false);
+        performSpiWiretapping(spiCookie);
 #endif /* FSFW_LINUX_SPI_WIRETAPPING == 1 */
     }
     else {
@@ -246,17 +255,21 @@ ReturnValue_t SpiComIF::getSendSuccess(CookieIF *cookie) {
 }
 
 ReturnValue_t SpiComIF::requestReceiveMessage(CookieIF *cookie, size_t requestLen) {
-    ReturnValue_t result = HasReturnvaluesIF::RETURN_OK;
     SpiCookie* spiCookie = dynamic_cast<SpiCookie*>(cookie);
     if(spiCookie == nullptr) {
         return NULLPOINTER;
     }
 
-    bool fullDuplex = spiCookie->isFullDuplex();
-    if(fullDuplex) {
+    if(spiCookie->isFullDuplex()) {
         return HasReturnvaluesIF::RETURN_OK;
     }
 
+    return performHalfDuplexReception(spiCookie);
+}
+
+
+ReturnValue_t SpiComIF::performHalfDuplexReception(SpiCookie* spiCookie) {
+    ReturnValue_t result = HasReturnvaluesIF::RETURN_OK;
     std::string device = spiCookie->getSpiDevice();
     int fileDescriptor = 0;
     UnixFileGuard fileHelper(device, &fileDescriptor, O_RDWR,
@@ -306,7 +319,7 @@ ReturnValue_t SpiComIF::requestReceiveMessage(CookieIF *cookie, size_t requestLe
         }
     }
 
-    return HasReturnvaluesIF::RETURN_OK;
+    return result;
 }
 
 ReturnValue_t SpiComIF::readReceivedMessage(CookieIF *cookie, uint8_t **buffer, size_t *size) {
@@ -325,10 +338,35 @@ ReturnValue_t SpiComIF::readReceivedMessage(CookieIF *cookie, uint8_t **buffer,
     return HasReturnvaluesIF::RETURN_OK;
 }
 
-MutexIF* SpiComIF::getMutex() {
+MutexIF* SpiComIF::getMutex(MutexIF::TimeoutType* timeoutType, uint32_t* timeoutMs) {
+    if(timeoutType != nullptr) {
+        *timeoutType = this->timeoutType;
+    }
+    if(timeoutMs != nullptr) {
+        *timeoutMs = this->timeoutMs;
+    }
     return spiMutex;
 }
 
+void SpiComIF::performSpiWiretapping(SpiCookie* spiCookie) {
+    if(spiCookie == nullptr) {
+        return;
+    }
+    size_t dataLen = spiCookie->getTransferStructHandle()->len;
+    uint8_t* dataPtr = reinterpret_cast<uint8_t*>(spiCookie->getTransferStructHandle()->tx_buf);
+#if FSFW_CPP_OSTREAM_ENABLED == 1
+    sif::info << "Sent SPI data: " << std::endl;
+    arrayprinter::print(dataPtr, dataLen, OutputType::HEX, false);
+    sif::info << "Received SPI data: " << std::endl;
+#else
+    sif::printInfo("Sent SPI data: \n");
+    arrayprinter::print(dataPtr, dataLen, OutputType::HEX, false);
+    sif::printInfo("Received SPI data: \n");
+#endif /* FSFW_CPP_OSTREAM_ENABLED == 1 */
+    dataPtr = reinterpret_cast<uint8_t*>(spiCookie->getTransferStructHandle()->rx_buf);
+    arrayprinter::print(dataPtr, dataLen, OutputType::HEX, false);
+}
+
 ReturnValue_t SpiComIF::getReadBuffer(address_t spiAddress, uint8_t** buffer) {
     if(buffer == nullptr) {
         return HasReturnvaluesIF::RETURN_FAILED;
@@ -343,6 +381,10 @@ ReturnValue_t SpiComIF::getReadBuffer(address_t spiAddress, uint8_t** buffer) {
     return HasReturnvaluesIF::RETURN_OK;
 }
 
+GpioIF* SpiComIF::getGpioInterface() {
+    return gpioComIF;
+}
+
 void SpiComIF::setSpiSpeedAndMode(int spiFd, spi::SpiModes mode, uint32_t speed) {
     int retval = ioctl(spiFd, SPI_IOC_WR_MODE, reinterpret_cast<uint8_t*>(&mode));
     if(retval != 0) {

linux/spi/SpiComIF.h

@@ -2,8 +2,8 @@
 #define LINUX_SPI_SPICOMIF_H_
 
 #include "spiDefinitions.h"
-#include <returnvalues/classIds.h>
-#include <fsfw_hal/common/gpio/GpioIF.h>
+#include "returnvalues/classIds.h"
+#include "../../common/gpio/GpioIF.h"
 
 #include <fsfw/devicehandlers/DeviceCommunicationIF.h>
 #include <fsfw/objectmanager/SystemObject.h>
@@ -11,10 +11,13 @@
 #include <vector>
 #include <unordered_map>
 
+class SpiCookie;
+
 /**
  * @brief   Encapsulates access to linux SPI driver for FSFW objects
  * @details
- * Right now, only full-duplex SPI is supported.
+ * Right now, only full-duplex SPI is supported. Most device specific transfer properties
+ * are contained in the SPI cookie.
  * @author  R. Mueller
  */
 class SpiComIF: public DeviceCommunicationIF, public SystemObject {
@@ -39,11 +42,28 @@ public:
             size_t requestLen) override;
     ReturnValue_t readReceivedMessage(CookieIF *cookie, uint8_t **buffer,
             size_t *size) override;
+
     /**
      * @brief   This function returns the mutex which can be used to protect the spi bus when
      *          the chip select must be driven from outside of the com if.
      */
-    MutexIF* getMutex();
+    MutexIF* getMutex(MutexIF::TimeoutType* timeoutType = nullptr, uint32_t* timeoutMs = nullptr);
+
+    /**
+     * Perform a regular send operation using Linux iotcl. This is public so it can be used
+     * in functions like a user callback if special handling is only necessary for certain commands.
+     * @param spiCookie
+     * @param sendData
+     * @param sendLen
+     * @return
+     */
+    ReturnValue_t performRegularSendOperation(SpiCookie* spiCookie, const uint8_t *sendData,
+            size_t sendLen);
+
+    GpioIF* getGpioInterface();
+    void setSpiSpeedAndMode(int spiFd, spi::SpiModes mode, uint32_t speed);
+    void performSpiWiretapping(SpiCookie* spiCookie);
+
 private:
 
     struct SpiInstance {
@@ -61,9 +81,9 @@ private:
 
     SpiDeviceMap spiDeviceMap;
 
+    ReturnValue_t performHalfDuplexReception(SpiCookie* spiCookie);
 
     ReturnValue_t getReadBuffer(address_t spiAddress, uint8_t** buffer);
-    void setSpiSpeedAndMode(int spiFd, spi::SpiModes mode, uint32_t speed);
 };
 
 #endif /* LINUX_SPI_SPICOMIF_H_ */

linux/spi/SpiCookie.cpp

@@ -1,14 +1,34 @@
 #include "SpiCookie.h"
 
 SpiCookie::SpiCookie(address_t spiAddress, gpioId_t chipSelect, std::string spiDev,
-        const size_t maxSize, spi::SpiModes spiMode, uint32_t spiSpeed): spiAddress(spiAddress),
-        chipSelectPin(chipSelect), spiDevice(spiDev), maxSize(maxSize), spiMode(spiMode),
-        spiSpeed(spiSpeed) {
+        const size_t maxSize, spi::SpiModes spiMode, uint32_t spiSpeed):
+        SpiCookie(spi::SpiComIfModes::REGULAR, spiAddress, chipSelect, spiDev, maxSize, spiMode,
+                spiSpeed, nullptr, nullptr) {
+
 }
 
 SpiCookie::SpiCookie(address_t spiAddress, std::string spiDev, const size_t maxSize,
         spi::SpiModes spiMode, uint32_t spiSpeed):
-        SpiCookie(spiAddress, gpio::NO_GPIO, spiDev, maxSize, spiMode, spiSpeed) {
+                SpiCookie(spiAddress, gpio::NO_GPIO, spiDev, maxSize, spiMode, spiSpeed) {
+}
+
+SpiCookie::SpiCookie(address_t spiAddress, gpioId_t chipSelect, std::string spiDev,
+        const size_t maxSize, spi::SpiModes spiMode, uint32_t spiSpeed,
+        spi::send_callback_function_t callback, void *args):
+		        SpiCookie(spi::SpiComIfModes::CALLBACK, spiAddress, chipSelect, spiDev, maxSize,
+		                spiMode, spiSpeed, callback, args) {
+}
+
+SpiCookie::SpiCookie(spi::SpiComIfModes comIfMode, address_t spiAddress, gpioId_t chipSelect,
+        std::string spiDev, const size_t maxSize, spi::SpiModes spiMode, uint32_t spiSpeed,
+        spi::send_callback_function_t callback, void* args):
+                spiAddress(spiAddress), chipSelectPin(chipSelect), spiDevice(spiDev),
+                comIfMode(comIfMode), maxSize(maxSize), spiMode(spiMode), spiSpeed(spiSpeed),
+                sendCallback(callback), callbackArgs(args) {
+}
+
+spi::SpiComIfModes SpiCookie::getComIfMode() const {
+    return this->comIfMode;
 }
 
 void SpiCookie::getSpiParameters(spi::SpiModes& spiMode, uint32_t& spiSpeed,
@@ -78,6 +98,13 @@ void SpiCookie::assignWriteBuffer(const uint8_t* tx) {
     }
 }
 
+void SpiCookie::setCallbackMode(spi::send_callback_function_t callback,
+        void *args) {
+    this->comIfMode = spi::SpiComIfModes::CALLBACK;
+    this->sendCallback = callback;
+    this->callbackArgs = args;
+}
+
 spi_ioc_transfer* SpiCookie::getTransferStructHandle() {
     return &spiTransferStruct;
 }
@@ -105,3 +132,9 @@ void SpiCookie::setSpiSpeed(uint32_t newSpeed) {
 void SpiCookie::setSpiMode(spi::SpiModes newMode) {
     this->spiMode = newMode;
 }
+
+void SpiCookie::getCallback(spi::send_callback_function_t *callback,
+        void **args) {
+    *callback = this->sendCallback;
+    *args = this->callbackArgs;
+}

linux/spi/SpiCookie.h

@@ -2,13 +2,25 @@
 #define LINUX_SPI_SPICOOKIE_H_
 
 #include "spiDefinitions.h"
+#include "../../common/gpio/gpioDefinitions.h"
+
 #include <fsfw/devicehandlers/CookieIF.h>
-#include <fsfw_hal/common/gpio/gpioDefinitions.h>
+
 #include <linux/spi/spidev.h>
 
+/**
+ * @brief   This cookie class is passed to the SPI communication interface
+ * @details
+ * This cookie contains device specific properties like speed and SPI mode or the SPI transfer
+ * struct required by the Linux SPI driver. It also contains a handle to a GPIO interface
+ * to perform slave select switching when necessary.
+ *
+ * The user can specify gpio::NO_GPIO as the GPIO ID or use a custom send callback to meet
+ * special requirements like expander slave select switching (e.g. GPIO or I2C expander)
+ * or special timing related requirements.
+ */
 class SpiCookie: public CookieIF {
 public:
-
     /**
      * Each SPI device will have a corresponding cookie. The cookie is used by the communication
      * interface and contains device specific information like the largest expected size to be
@@ -19,7 +31,7 @@ public:
      * @param maxSize
      */
     SpiCookie(address_t spiAddress, gpioId_t chipSelect, std::string spiDev,
-            const size_t maxReplySize, spi::SpiModes spiMode, uint32_t spiSpeed);
+            const size_t maxSize, spi::SpiModes spiMode, uint32_t spiSpeed);
 
     /**
      * Like constructor above, but without a dedicated GPIO CS. Can be used for hardware
@@ -28,16 +40,41 @@ public:
     SpiCookie(address_t spiAddress, std::string spiDev, const size_t maxReplySize,
             spi::SpiModes spiMode, uint32_t spiSpeed);
 
+    /**
+     * Use the callback mode of the SPI communication interface. The user can pass the callback
+     * function here or by using the setter function #setCallbackMode
+     */
+    SpiCookie(address_t spiAddress, gpioId_t chipSelect, std::string spiDev, const size_t maxSize,
+            spi::SpiModes spiMode, uint32_t spiSpeed, spi::send_callback_function_t callback,
+            void *args);
+
+    /**
+     * Get the callback function
+     * @param callback
+     * @param args
+     */
+    void getCallback(spi::send_callback_function_t* callback, void** args);
+
     address_t getSpiAddress() const;
     std::string getSpiDevice() const;
     gpioId_t getChipSelectPin() const;
     size_t getMaxBufferSize() const;
 
+    spi::SpiComIfModes getComIfMode() const;
+
     /** Enables changing SPI speed at run-time */
     void setSpiSpeed(uint32_t newSpeed);
     /** Enables changing the SPI mode at run-time */
     void setSpiMode(spi::SpiModes newMode);
 
+    /**
+     * Set the SPI to callback mode and assigns the user supplied callback and an argument
+     * passed to the callback.
+     * @param callback
+     * @param args
+     */
+    void setCallbackMode(spi::send_callback_function_t callback, void* args);
+
     /**
      * True if SPI transfers should be performed in full duplex mode
      * @return
@@ -99,17 +136,40 @@ public:
 
     spi_ioc_transfer* getTransferStructHandle();
 private:
+
+    /**
+     * Internal constructor which initializes every field
+     * @param spiAddress
+     * @param chipSelect
+     * @param spiDev
+     * @param maxSize
+     * @param spiMode
+     * @param spiSpeed
+     * @param callback
+     * @param args
+     */
+    SpiCookie(spi::SpiComIfModes comIfMode, address_t spiAddress, gpioId_t chipSelect,
+            std::string spiDev, const size_t maxSize, spi::SpiModes spiMode, uint32_t spiSpeed,
+            spi::send_callback_function_t callback, void* args);
+
     size_t currentTransferSize = 0;
 
     address_t spiAddress;
     gpioId_t chipSelectPin;
     std::string spiDevice;
 
+    spi::SpiComIfModes comIfMode;
+
+    // Required for regular mode
     const size_t maxSize;
     spi::SpiModes spiMode;
     uint32_t spiSpeed;
     bool halfDuplex = false;
 
+    // Required for callback mode
+    spi::send_callback_function_t sendCallback = nullptr;
+    void* callbackArgs = nullptr;
+
     struct spi_ioc_transfer spiTransferStruct = {};
     UncommonParameters uncommonParameters;
 };

linux/spi/spiDefinitions.h

@@ -1,8 +1,16 @@
 #ifndef LINUX_SPI_SPIDEFINITONS_H_
 #define LINUX_SPI_SPIDEFINITONS_H_
 
+#include "../../common/gpio/gpioDefinitions.h"
+
+#include "fsfw/returnvalues/HasReturnvaluesIF.h"
+#include <linux/spi/spidev.h>
+
 #include <cstdint>
 
+class SpiCookie;
+class SpiComIF;
+
 namespace spi {
 
 enum SpiModes: uint8_t {
@@ -12,6 +20,15 @@ enum SpiModes: uint8_t {
     MODE_3
 };
 
+enum SpiComIfModes {
+	REGULAR,
+	CALLBACK
+};
+
+
+using send_callback_function_t = ReturnValue_t (*) (SpiComIF* comIf, SpiCookie *cookie,
+        const uint8_t *sendData, size_t sendLen, void* args);
+
 }
 
 #endif /* LINUX_SPI_SPIDEFINITONS_H_ */

linux/uart/CMakeLists.txt

@@ -0,0 +1,8 @@
+target_sources(${TARGET_NAME} PUBLIC
+	UartComIF.cpp
+	UartCookie.cpp
+)
+
+
+
+

linux/uart/UartComIF.cpp

@@ -0,0 +1,370 @@
+#include "UartComIF.h"
+
+#include <fsfw/serviceinterface/ServiceInterface.h>
+
+#include <cstring>
+#include <fcntl.h>
+#include <errno.h>
+#include <termios.h>
+#include <unistd.h>
+
+UartComIF::UartComIF(object_id_t objectId): SystemObject(objectId){
+}
+
+UartComIF::~UartComIF() {}
+
+ReturnValue_t UartComIF::initializeInterface(CookieIF * cookie) {
+
+	std::string deviceFile;
+	UartDeviceMapIter uartDeviceMapIter;
+
+	if(cookie == nullptr) {
+		return NULLPOINTER;
+	}
+
+    UartCookie* uartCookie = dynamic_cast<UartCookie*>(cookie);
+    if (uartCookie == nullptr) {
+        sif::error << "UartComIF::initializeInterface: Invalid UART Cookie!" << std::endl;
+        return NULLPOINTER;
+    }
+
+    deviceFile = uartCookie->getDeviceFile();
+
+    uartDeviceMapIter = uartDeviceMap.find(deviceFile);
+	if(uartDeviceMapIter == uartDeviceMap.end()) {
+	    int fileDescriptor = configureUartPort(uartCookie);
+	    if (fileDescriptor < 0) {
+	        return RETURN_FAILED;
+	    }
+	    size_t maxReplyLen = uartCookie->getMaxReplyLen();
+		UartElements_t uartElements = {fileDescriptor, std::vector<uint8_t>(maxReplyLen), 0};
+		std::pair status = uartDeviceMap.emplace(deviceFile, uartElements);
+        if (status.second == false) {
+            sif::debug << "UartComIF::initializeInterface: Failed to insert device "  << deviceFile
+                    << "to Uart device map" << std::endl;
+            return RETURN_FAILED;
+        }
+	}
+	else {
+		sif::debug << "UartComIF::initializeInterface: Uart device " << deviceFile << "already in "
+		        << "use" << std::endl;
+		return RETURN_FAILED;
+	}
+
+	return RETURN_OK;
+}
+
+int UartComIF::configureUartPort(UartCookie* uartCookie) {
+
+    struct termios options;
+
+    std::string deviceFile = uartCookie->getDeviceFile();
+    int fd = open(deviceFile.c_str(), O_RDWR);
+
+    if (fd < 0) {
+        sif::debug << "UartComIF::configureUartPort: Failed to open uart " << deviceFile << "with"
+                << " error code " << errno << strerror(errno) << std::endl;
+        return fd;
+    }
+
+    /* Read in existing settings */
+    if(tcgetattr(fd, &options) != 0) {
+        sif::debug << "UartComIF::configureUartPort: Error " << errno << "from tcgetattr: "
+                << strerror(errno) << std::endl;
+        return fd;
+    }
+
+    setParityOptions(&options, uartCookie);
+    setStopBitOptions(&options, uartCookie);
+    setDatasizeOptions(&options, uartCookie);
+    setFixedOptions(&options);
+
+    /* Sets uart to non-blocking mode. Read returns immediately when there are no data available */
+    options.c_cc[VTIME] = 0;
+    options.c_cc[VMIN] = 0;
+
+    configureBaudrate(&options, uartCookie);
+
+    /* Save option settings */
+    if (tcsetattr(fd, TCSANOW, &options) != 0) {
+        sif::debug << "UartComIF::configureUartPort: Failed to set options with error " << errno
+                << ": " << strerror(errno);
+        return fd;
+    }
+    return fd;
+}
+
+void UartComIF::setParityOptions(struct termios* options, UartCookie* uartCookie) {
+    /* Clear parity bit */
+    options->c_cflag &= ~PARENB;
+    switch (uartCookie->getParity()) {
+    case Parity::EVEN:
+        options->c_cflag |= PARENB;
+        options->c_cflag &= ~PARODD;
+        break;
+    case Parity::ODD:
+        options->c_cflag |= PARENB;
+        options->c_cflag |= PARODD;
+        break;
+    default:
+        break;
+    }
+}
+
+void UartComIF::setStopBitOptions(struct termios* options, UartCookie* uartCookie) {
+    /* Clear stop field. Sets stop bit to one bit */
+    options->c_cflag &= ~CSTOPB;
+    switch (uartCookie->getStopBits()) {
+    case StopBits::TWO_STOP_BITS:
+        options->c_cflag |= CSTOPB;
+        break;
+    default:
+        break;
+    }
+}
+
+void UartComIF::setDatasizeOptions(struct termios* options, UartCookie* uartCookie) {
+    /* Clear size bits */
+    options->c_cflag &= ~CSIZE;
+    switch (uartCookie->getBitsPerWord()) {
+    case 5:
+        options->c_cflag |= CS5;
+        break;
+    case 6:
+        options->c_cflag |= CS6;
+        break;
+    case 7:
+        options->c_cflag |= CS7;
+        break;
+    case 8:
+        options->c_cflag |= CS8;
+        break;
+    default:
+        sif::debug << "UartComIF::setDatasizeOptions: Invalid size specified" << std::endl;
+        break;
+    }
+}
+
+void UartComIF::setFixedOptions(struct termios* options) {
+    /* Disable RTS/CTS hardware flow control */
+    options->c_cflag &= ~CRTSCTS;
+    /* Turn on READ & ignore ctrl lines (CLOCAL = 1) */
+    options->c_cflag |= CREAD | CLOCAL;
+    /* Disable canonical mode */
+    options->c_lflag &= ~ICANON;
+    /* Disable echo */
+    options->c_lflag &= ~ECHO;
+    /* Disable erasure */
+    options->c_lflag &= ~ECHOE;
+    /* Disable new-line echo */
+    options->c_lflag &= ~ECHONL;
+    /* Disable interpretation of INTR, QUIT and SUSP */
+    options->c_lflag &= ~ISIG;
+    /* Turn off s/w flow ctrl */
+    options->c_iflag &= ~(IXON | IXOFF | IXANY);
+    /* Disable any special handling of received bytes */
+    options->c_iflag &= ~(IGNBRK|BRKINT|PARMRK|ISTRIP|INLCR|IGNCR|ICRNL);
+    /* Prevent special interpretation of output bytes (e.g. newline chars) */
+    options->c_oflag &= ~OPOST;
+    /* Prevent conversion of newline to carriage return/line feed */
+    options->c_oflag &= ~ONLCR;
+}
+
+void UartComIF::configureBaudrate(struct termios* options, UartCookie* uartCookie) {
+    switch (uartCookie->getBaudrate()) {
+    case 50:
+        cfsetispeed(options, B50);
+        cfsetospeed(options, B50);
+        break;
+    case 75:
+        cfsetispeed(options, B75);
+        cfsetospeed(options, B75);
+        break;
+    case 110:
+        cfsetispeed(options, B110);
+        cfsetospeed(options, B110);
+        break;
+    case 134:
+        cfsetispeed(options, B134);
+        cfsetospeed(options, B134);
+        break;
+    case 150:
+        cfsetispeed(options, B150);
+        cfsetospeed(options, B150);
+        break;
+    case 200:
+        cfsetispeed(options, B200);
+        cfsetospeed(options, B200);
+        break;
+    case 300:
+        cfsetispeed(options, B300);
+        cfsetospeed(options, B300);
+        break;
+    case 600:
+        cfsetispeed(options, B600);
+        cfsetospeed(options, B600);
+        break;
+    case 1200:
+        cfsetispeed(options, B1200);
+        cfsetospeed(options, B1200);
+        break;
+    case 1800:
+        cfsetispeed(options, B1800);
+        cfsetospeed(options, B1800);
+        break;
+    case 2400:
+        cfsetispeed(options, B2400);
+        cfsetospeed(options, B2400);
+        break;
+    case 4800:
+        cfsetispeed(options, B4800);
+        cfsetospeed(options, B4800);
+        break;
+    case 9600:
+        cfsetispeed(options, B9600);
+        cfsetospeed(options, B9600);
+        break;
+    case 19200:
+        cfsetispeed(options, B19200);
+        cfsetospeed(options, B19200);
+        break;
+    case 38400:
+        cfsetispeed(options, B38400);
+        cfsetospeed(options, B38400);
+        break;
+    case 57600:
+        cfsetispeed(options, B57600);
+        cfsetospeed(options, B57600);
+        break;
+    case 115200:
+        cfsetispeed(options, B115200);
+        cfsetospeed(options, B115200);
+        break;
+    case 230400:
+        cfsetispeed(options, B230400);
+        cfsetospeed(options, B230400);
+        break;
+    case 460800:
+        cfsetispeed(options, B460800);
+        cfsetospeed(options, B460800);
+        break;
+    default:
+        sif::warning << "UartComIF::configureBaudrate: Baudrate not supported" << std::endl;
+        break;
+    }
+}
+
+ReturnValue_t UartComIF::sendMessage(CookieIF *cookie,
+        const uint8_t *sendData, size_t sendLen) {
+
+	int fd = 0;
+	std::string deviceFile;
+	UartDeviceMapIter uartDeviceMapIter;
+
+	if(sendData == nullptr) {
+        sif::debug << "UartComIF::sendMessage: Send Data is nullptr" << std::endl;
+	    return RETURN_FAILED;
+	}
+
+	if(sendLen == 0) {
+		return RETURN_OK;
+	}
+
+	UartCookie* uartCookie = dynamic_cast<UartCookie*>(cookie);
+	if(uartCookie == nullptr) {
+        sif::debug << "UartComIF::sendMessasge: Invalid Uart Cookie!" << std::endl;
+		return NULLPOINTER;
+	}
+
+	deviceFile = uartCookie->getDeviceFile();
+	uartDeviceMapIter = uartDeviceMap.find(deviceFile);
+	if (uartDeviceMapIter == uartDeviceMap.end()) {
+		sif::debug << "UartComIF::sendMessage: Device file " << deviceFile << "not in uart map"
+		        << std::endl;
+		return RETURN_FAILED;
+	}
+
+	fd = uartDeviceMapIter->second.fileDescriptor;
+
+	if (write(fd, sendData, sendLen) != (int)sendLen) {
+		sif::error << "UartComIF::sendMessage: Failed to send data with error code " << errno
+		        << ": Error description: " << strerror(errno) << std::endl;
+		return RETURN_FAILED;
+	}
+
+	return RETURN_OK;
+}
+
+ReturnValue_t UartComIF::getSendSuccess(CookieIF *cookie) {
+	return RETURN_OK;
+}
+
+ReturnValue_t UartComIF::requestReceiveMessage(CookieIF *cookie,
+		size_t requestLen) {
+
+    int fd = 0;
+    std::string deviceFile;
+    UartDeviceMapIter uartDeviceMapIter;
+    uint8_t* bufferPtr;
+
+    if(requestLen == 0) {
+        return RETURN_OK;
+    }
+
+    UartCookie* uartCookie = dynamic_cast<UartCookie*>(cookie);
+    if(uartCookie == nullptr) {
+        sif::debug << "UartComIF::requestReceiveMessage: Invalid Uart Cookie!" << std::endl;
+        return NULLPOINTER;
+    }
+
+    deviceFile = uartCookie->getDeviceFile();
+    uartDeviceMapIter = uartDeviceMap.find(deviceFile);
+    if (uartDeviceMapIter == uartDeviceMap.end()) {
+        sif::debug << "UartComIF::requestReceiveMessage: Device file " << deviceFile
+                << " not in uart map" << std::endl;
+        return RETURN_FAILED;
+    }
+
+    fd = uartDeviceMapIter->second.fileDescriptor;
+    bufferPtr = uartDeviceMapIter->second.replyBuffer.data();
+    int bytesRead = read(fd, bufferPtr, requestLen);
+    if (bytesRead != static_cast<int>(requestLen)) {
+        sif::debug << "UartComIF::requestReceiveMessage: Only read " << bytesRead
+        << " of " << requestLen << " bytes" << std::endl;
+        return RETURN_FAILED;
+    }
+    else {
+        uartDeviceMapIter->second.replyLen = bytesRead;
+    }
+
+    return RETURN_OK;
+}
+
+ReturnValue_t UartComIF::readReceivedMessage(CookieIF *cookie,
+		uint8_t **buffer, size_t* size) {
+
+    std::string deviceFile;
+    UartDeviceMapIter uartDeviceMapIter;
+
+    UartCookie* uartCookie = dynamic_cast<UartCookie*>(cookie);
+	if(uartCookie == nullptr) {
+        sif::debug << "UartComIF::readReceivedMessage: Invalid uart cookie!" << std::endl;
+		return NULLPOINTER;
+	}
+
+	deviceFile = uartCookie->getDeviceFile();
+    uartDeviceMapIter = uartDeviceMap.find(deviceFile);
+    if (uartDeviceMapIter == uartDeviceMap.end()) {
+        sif::debug << "UartComIF::readReceivedMessage: Device file " << deviceFile
+                << " not in uart map" << std::endl;
+        return RETURN_FAILED;
+    }
+
+	*buffer = uartDeviceMapIter->second.replyBuffer.data();
+	*size = uartDeviceMapIter->second.replyLen;
+
+	/* Length is reset to 0 to prevent reading the same data twice */
+	uartDeviceMapIter->second.replyLen = 0;
+
+	return RETURN_OK;
+}

linux/uart/UartComIF.h

@@ -0,0 +1,94 @@
+#ifndef BSP_Q7S_COMIF_UARTCOMIF_H_
+#define BSP_Q7S_COMIF_UARTCOMIF_H_
+
+#include <fsfw/objectmanager/SystemObject.h>
+#include <fsfw/devicehandlers/DeviceCommunicationIF.h>
+
+#include <unordered_map>
+#include <vector>
+
+#include "UartCookie.h"
+
+/**
+ * @brief 	This is the communication interface to access serial ports on linux based operating
+ *          systems.
+ *
+ * @details The implementation follows the instructions from https://blog.mbedded.ninja/programming/
+ *          operating-systems/linux/linux-serial-ports-using-c-cpp/#disabling-canonical-mode
+ *
+ * @author 	J. Meier
+ */
+class UartComIF: public DeviceCommunicationIF, public SystemObject {
+public:
+	UartComIF(object_id_t objectId);
+
+	virtual ~UartComIF();
+
+	ReturnValue_t initializeInterface(CookieIF * cookie) override;
+	ReturnValue_t sendMessage(CookieIF *cookie,const uint8_t *sendData,
+			size_t sendLen) override;
+	ReturnValue_t getSendSuccess(CookieIF *cookie) override;
+	ReturnValue_t requestReceiveMessage(CookieIF *cookie,
+	        size_t requestLen) override;
+	ReturnValue_t readReceivedMessage(CookieIF *cookie, uint8_t **buffer,
+			size_t *size) override;
+
+private:
+
+	using UartDeviceFile_t = std::string;
+
+	typedef struct UartElements {
+	    int fileDescriptor;
+		std::vector<uint8_t> replyBuffer;
+		/** Number of bytes read will be written to this variable */
+		size_t replyLen;
+	} UartElements_t;
+
+	using UartDeviceMap = std::unordered_map<UartDeviceFile_t, UartElements_t>;
+	using UartDeviceMapIter = UartDeviceMap::iterator;
+
+	/**
+	 * The uart devie map stores informations of initialized uart ports.
+	 */
+	UartDeviceMap uartDeviceMap;
+
+	/**
+	 * @brief	This function opens and configures a uart device by using the information stored
+	 *          in the uart cookie.
+	 * @param uartCookie    Pointer to uart cookie with information about the uart. Contains the
+	 *                      uart device file, baudrate, parity, stopbits etc.
+	 * @return  The file descriptor of the configured uart.
+	 */
+	int configureUartPort(UartCookie* uartCookie);
+
+	/**
+	 * @brief   This function adds the parity settings to the termios options struct.
+	 *
+	 * @param options   Pointer to termios options struct which will be modified to enable or disable
+	 *                  parity checking.
+	 * @param uartCookie    Pointer to uart cookie containing the information about the desired
+	 *                      parity settings.
+	 *
+	 */
+	void setParityOptions(struct termios* options, UartCookie* uartCookie);
+
+	void setStopBitOptions(struct termios* options, UartCookie* uartCookie);
+
+	/**
+	 * @brief   This function sets options which are not configurable by the uartCookie.
+	 */
+	void setFixedOptions(struct termios* options);
+
+	/**
+	 * @brief   With this function the datasize settings are added to the termios options struct.
+	 */
+	void setDatasizeOptions(struct termios* options, UartCookie* uartCookie);
+
+	/**
+	 * @brief   This functions adds the  baudrate specified in the uartCookie to the termios options
+	 *          struct.
+	 */
+	void configureBaudrate(struct termios* options, UartCookie* uartCookie);
+};
+
+#endif /* BSP_Q7S_COMIF_UARTCOMIF_H_ */

linux/uart/UartCookie.cpp

@@ -0,0 +1,63 @@
+#include "UartCookie.h"
+
+#include <fsfw/serviceinterface/ServiceInterface.h>
+
+UartCookie::UartCookie(std::string deviceFile, uint32_t baudrate, size_t maxReplyLen) :
+        deviceFile(deviceFile), baudrate(baudrate), maxReplyLen(maxReplyLen) {
+}
+
+UartCookie::~UartCookie() {}
+
+uint32_t UartCookie::getBaudrate() const {
+	return baudrate;
+}
+
+size_t UartCookie::getMaxReplyLen() const {
+	return maxReplyLen;
+}
+
+std::string UartCookie::getDeviceFile() const {
+	return deviceFile;
+}
+
+void UartCookie::setParityOdd() {
+    parity = Parity::ODD;
+}
+
+void UartCookie::setParityEven() {
+    parity = Parity::EVEN;
+}
+
+Parity UartCookie::getParity() const {
+    return parity;
+}
+
+void UartCookie::setBitsPerWord(uint8_t bitsPerWord_) {
+    switch(bitsPerWord_) {
+    case 5:
+    case 6:
+    case 7:
+    case 8:
+        break;
+    default:
+        sif::debug << "UartCookie::setBitsPerWord: Invalid bits per word specified" << std::endl;
+        return;
+    }
+    bitsPerWord = bitsPerWord_;
+}
+
+uint8_t UartCookie::getBitsPerWord() const {
+    return bitsPerWord;
+}
+
+StopBits UartCookie::getStopBits() const {
+    return stopBits;
+}
+
+void UartCookie::setTwoStopBits() {
+    stopBits = StopBits::TWO_STOP_BITS;
+}
+
+void UartCookie::setOneStopBit() {
+    stopBits = StopBits::ONE_STOP_BIT;
+}

linux/uart/UartCookie.h

@@ -0,0 +1,81 @@
+#ifndef SAM9G20_COMIF_COOKIES_UART_COOKIE_H_
+#define SAM9G20_COMIF_COOKIES_UART_COOKIE_H_
+
+#include <fsfw/devicehandlers/CookieIF.h>
+#include <string>
+
+enum class Parity {
+    NONE,
+    EVEN,
+    ODD
+};
+
+enum class StopBits {
+    ONE_STOP_BIT,
+    TWO_STOP_BITS
+};
+
+/**
+ * @brief   Cookie for the UartComIF. There are many options available to configure the uart driver.
+ *          The constructor only requests for common options like the baudrate. Other options can
+ *          be set by member functions.
+ *
+ * @author 	J. Meier
+ */
+class UartCookie: public CookieIF {
+public:
+
+	/**
+	 * @brief	Constructor for the uart cookie.
+	 * @param deviceFile    The device file specifying the uart to use. E.g. "/dev/ttyPS1".
+     * @param baudrate      The baudrate to use for input and output. Possible Baudrates are: 50,
+     *                      75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800, 9600, B19200,
+     *                      38400, 57600, 115200, 230400, 460800
+     * @param maxReplyLen   The maximum size an object using this cookie expects.
+     *
+     * @details Default configuration: No parity
+     *                                 8 databits (number of bits transfered with one uart frame)
+     *                                 One stop bit
+     *
+     *
+	 */
+    UartCookie(std::string deviceFile, uint32_t baudrate, size_t maxReplyLen);
+
+	virtual ~UartCookie();
+
+	uint32_t getBaudrate() const;
+	size_t getMaxReplyLen() const;
+	std::string getDeviceFile() const;
+	Parity getParity() const;
+	uint8_t getBitsPerWord() const;
+	StopBits getStopBits() const;
+
+	/**
+	 * Functions two enable parity checking.
+	 */
+	void setParityOdd();
+    void setParityEven();
+
+    /**
+     * Function two set number of bits per UART frame.
+     */
+	void setBitsPerWord(uint8_t bitsPerWord_);
+
+	/**
+	 * Function to specify the number of stopbits.
+	 */
+	void setTwoStopBits();
+	void setOneStopBit();
+
+
+private:
+
+	std::string deviceFile;
+	uint32_t baudrate;
+	size_t maxReplyLen = 0;
+	Parity parity = Parity::NONE;
+	uint8_t bitsPerWord = 8;
+	StopBits stopBits = StopBits::ONE_STOP_BIT;
+};
+
+#endif