5.6. Connext Micro on AUTOSAR

5.6.1. Introduction

Connext Micro includes support for AUTOSAR™ and enables Connext Micro applications to run on AUTOSAR systems. The support has been tested on the Infineon™ AURIX™ Application Kit TC297 TFT development board with Elektrobit™ (EB) AUTOSAR implementation version 4.0.3 and Mentor™ AUTOSAR implementation version 4.2.2 and compiler TASKING™ v6.2r2.

Note that Connext Micro requires the C-type “double” to be 64 bits. Any compiler option that treats a “double” as a “float” must not be enabled.

This manual explains how to compile and configure Connext Micro to run on AUTOSAR systems and the AUTOSAR configuration needed by Connext Micro.

• AUTOSAR Configuration

• AUTOSAR Port Details

• Compiling

• Interoperability

• Compiling Applications

5.6.2. AUTOSAR Configuration

5.6.2.1. Properties

AUTOSAR port properties must be set before any call to a Connext Micro API. This is done by using OSAPI_System_get_property() followed by OSAPI_System_set_property():

/* Example application with two areas in the heap */

#define NUMBER_OF_HEAP_AREAS 2
#define HEAP_AREA_1_SIZE 10*1024
#define HEAP_AREA_2_SIZE 130*1024

const RTI_PRIVATE uint32 heap_area_size[NUMBER_OF_HEAP_AREAS] =
{
    HEAP_AREA_1_SIZE,
    HEAP_AREA_2_SIZE
};

RTI_PRIVATE char heap_area1[HEAP_AREA_1_SIZE];
RTI_PRIVATE char heap_area2[HEAP_AREA_2_SIZE];

RTI_PRIVATE char* const heap_area[NUMBER_OF_HEAP_AREAS] =
{
    heap_area1,
    heap_area2
};

static Std_ReturnType
Application_get_socket(
    TcpIp_DomainType domain,
    TcpIp_ProtocolType protocol,
    P2VAR(TcpIp_SocketIdType, AUTOMATIC, TCPIP_APPL_DATA) socket_id)
{
    /* The name of this call depends on the SocketAdaptor name configured
     * in the AUTOSAR project
     */
    return TcpIp_TcpIpSocketOwner_0GetSocket(domain, protocol, socket_id);
}

RTI_BOOL
Application_set_system_properties(void)
{
    struct OSAPI_SystemProperty system_property;

    if (!OSAPI_System_get_property(&system_property))
    {
        printf("failed to get system properties\n");
        return RTI_FALSE;
    }

    /* Task OSAPI_SystemAutosar_timer_task is configured to run every 10 ms */
    system_property.port_property.timer_resolution_ms = 10;

    system_property.port_property.number_of_heap_areas = NUMBER_OF_HEAP_AREAS;
    system_property.port_property.heap_area_size = heap_area_size;
    system_property.port_property.heap_area = heap_area;

    /* Connext DDS Micro will use Resources as synchronization method */
    system_property.port_property.sync_type = OSAPI_AUTOSAR_SYNCKIND_RESOURCES;
    system_property.port_property.first_resource_id = RTIME_Resource01;
    system_property.port_property.last_resource_id = RTIME_Resource26;
    #if RTIME_AUTOSAR_SPINLOCK_ENABLED
    system_property.port_property.spinlock_id = 0;
    #endif /* RTI_CERT */

    system_property.port_property.semaphore_max_count = 2;
    system_property.port_property.first_give_event = RTIME_Semaphore_Give_Event;
    system_property.port_property.first_timeout_event = RTIME_Semaphore_Timeout_Event;
    system_property.port_property.first_alarm = RTIME_Semaphore_Alarm;

    system_property.port_property.use_socket_owner = TRUE;
    system_property.port_property.max_receive_sockets = 2;
    system_property.port_property.number_of_rcv_buffers = 0;
    system_property.port_property.rcv_buffer_size = 0;
    system_property.port_property.get_socket = Application_get_socket;
    system_property.port_property.send_data = NULL;
    system_property.port_property.local_addr_id = 0;

    system_property.port_property.use_udp_thread = FALSE;
    system_property.port_property.udp_receive_task_id = 0;
    system_property.port_property.udp_packet_received_event = 0;

    if (!OSAPI_System_set_property(&system_property))
    {
        printf("failed to set system properties\n");
        return RTI_FALSE;
    }

    return RTI_TRUE;
}

5.6.2.2. Tasks

5.6.2.2.1. Micro Timer Task

Connext Micro uses a timer task, which manages all the Connext Micro timers, such as deadline and liveliness timers. This task must be started before the first call to DDS_DomainParticipantFactory_get_instance(). This task must be run at a constant period, e.g., every 10 ms. Note that the priority of this task must be set based on the required system behavior.

It is important that the port properties are configured with the value of OSAPI_PortProperty::timer_resolution_ms equal to the Timer Task period.

This task needs at least 5 KB stack. The name of this task is OSAPI_SystemAutosar_timer_task. The task implementation can be found in the file autosarSystem.c.

5.6.2.2.2. Micro UDP Task

Connext Micro provides a callback function that must be called when a UDP packet is received. These callback functions are NETIO_Autosar_TcpIp_udp_rx_indication() and NETIO_Autosar_TcpIp_pdu_callout(). It is very important that one of these functions is called for the on-packet reception. Typically NETIO_Autosar_TcpIp_udp_rx_indication() is called when a SocketOwner is configured in the AUTOSAR configuration and NETIO_Autosar_TcpIp_pdu_callout() is typically used when SocketOwner is not configured in the AUTOSAR configuration.

It is important that the port properties are configured with a correct value in OSAPI_PortProperty::use_socket_owner. Set this field to TRUE only if you have configured SocketOwner in the AUTOSAR TcpIp configuration.

When Connext Micro receives an on-packet reception notification, the packet can be processed in the notification callback or in a different task. If OSAPI_PortProperty::use_udp_thread is set to TRUE, the packet is copied to an internal buffer, the “UDP Packet received event” is set, and the packet will be processed in a different task. Otherwise the packet is processed immediately.

The configuration of the OSAPI_PortProperty::use_udp_thread, OSAPI_PortProperty::udp_receive_task_id and OSAPI_PortProperty::udp_packet_received_event is the responsibility of the application.

Connext Micro requires one semaphore to be configured for the UDP Task if OSAPI_PortProperty::use_udp_thread is TRUE. This semaphore is used to temporarily suspend the UDP Task from a best-effort DDS DataReader if the DDS DataReader is unable to process new samples; this can happen if the DataReader is out of resources when samples have already been received by the network stack.

This semaphore must use the first OSAPI_PortProperty::first_give_event, OSAPI_PortProperty::first_timeout_event, and OSAPI_PortProperty::first_alarm. Please refer to Semaphores for details for how to configure semaphores.

Normally a UDP packet can be processed in the notification callback if the function OSAPI_Autosar_TcIp_udp_rx_indication() or NETIO_Autosar_TcpIp_pdu_callout() is called from another task. The UDP task is normally only needed in case OSAPI_Autosar_TcIp_udp_rx_indication() or NETIO_Autosar_TcpIp_pdu_callout() is called from an ISR.

This task should be started only once. Note that this is not a periodic task and the task never completes.

The UDP task waits for a “UDP Packet received event.” When this event is received, the task reads the packet from the internal buffer, processes it and waits again for the event.

This task must have at least 5 KB stack and must be configured as an extended task (only extended tasks can wait for an event).

The priority of this task must be assigned based on system requirements.

The name of this task is NETIO_Autosar_udp_receive_task and the task implementation can be found in the file autosarSocket.c.

The task configuration must include all necessary references to the event used to notify a UDP packet reception.

5.6.2.2.3. Application Task

The application task defines the DDS entities required by the application.

5.6.2.3. Critical Sections

Connext Micro can be configured to use different synchronization methods to protect critical sections. These critical sections synchronize access to objects shared among the different tasks (Timer task, UDP task, and user tasks).

First, configure the OSAPI_PortProperty::sync_type in the AUTOSAR port properties. For example, if Connext Micro is configured with tasks running on different cores, a Spinlock must be used.

The supported methods, and how to configure Connext Micro to use them, are described below:

• Resources

• Spinlock

For a cert build, the only synchronization method supported is Resources.

5.6.2.3.1. Resources

With this synchronization method, Connext Micro uses AUTOSAR resources to protect critical sections.

Only use this configuration if Connext Micro will be executed from one core.

All AUTOSAR resources used by Connext Micro must have consecutive IDs. Configure OSAPI_PortProperty::first_resource_id and OSAPI_PortProperty::last_resource_id with the “ID” of the first and last resource used by Connext Micro.

The number of resources needed depends on the number of DataWriter and DataReader objects that are created, the discovery plugin that is used, the AUTOSAR Configuration and the build configuration (whether the Log Module is excluded or not).

The following APIs and modules use one or more resources to protect critical sections:

API	Number of resources needed
AUTOSAR OSAPI Heap module	1
AUTOSAR OSAPI Mutex module	1
AUTOSAR NETIO UDP module	1 or 2. If the UDP task is used, by setting OSAPI_PortProperty::use_udp_thread to TRUE, one additional resource is needed to synchronize socket internal buffers.
DPDE discovery plugin	11
DPSE discovery plugin	5
DDS_DomainParticipantFactory_get_instance()	4 or 5. If the Log module is included in the compilation one additional resource is needed.
DDS_DomainParticipantFactory_create_participant()	2
DDS_DomainParticipant_create_topic()	1
DDS_DomainParticipant_create_publisher()	1
DDS_DomainParticipant_create_subscriber()	1
DDS_Publisher_create_datawriter()	1
DDS_Publisher_create_datareader()	1
DDS_WaitSet_new()	1

A basic Connext Micro application using the DPDE discovery plugin and one DataWriter uses 24 resources:

Table 5.1 Basic application using DPDE discovery plugin

API	Number of resources needed
AUTOSAR OSAPI Heap module	1
AUTOSAR OSAPI Mutex module	1
AUTOSAR NETIO UDP module	1
DPDE discovery plugin	11
DDS_DomainParticipantFactory_get_instance()	5 (Log module included in the compilation)
DDS_DomainParticipantFactory_create_participant()	2
DDS_DomainParticipant_create_topic()	1
DDS_DomainParticipant_create_publisher()	1
DDS_Publisher_create_datawriter()	1

A basic Connext Micro application using DPSE discovery plugin and one DataWriter uses 18 resources:

Table 5.2 Basic application using DPSE discovery plugin

API	Number of resources needed
AUTOSAR OSAPI Heap module	1
AUTOSAR OSAPI Mutex module	1
AUTOSAR NETIO UDP module	1
DPSE discovery plugin	5 (Log module included in the compilation)
DDS_DomainParticipantFactory_get_instance()	5
DDS_DomainParticipantFactory_create_participant()	2
DDS_DomainParticipant_create_topic()	1
DDS_DomainParticipant_create_publisher()	1
DDS_Publisher_create_datawriter()	1

To configure Connext Micro to use the resources to protect critical sections, set OSAPI_PortProperty::sync_type equal to OSAPI_Autosar_SyncKind_T::OSAPI_AUTOSAR_SYNCKIND_RESOURCES.

5.6.2.3.2. Spinlock

When the spinlock synchronization method is used, Connext Micro uses an OSEK spinlock to protect critical sections.

Only use this configuration if Connext Micro will be used from more than one core.

To configure Connext Micro to use spinlock to protect critical sections set OSAPI_PortProperty::sync_type equal to OSAPI_Autosar_SyncKind_T::OSAPI_AUTOSAR_SYNCKIND_SPINLOCK.

5.6.2.4. TCP/IP Configuration

A CDD socket owner can be optionally used. Set OSAPI_PortProperty::use_socket_owner to TRUE only if a SocketOwner is configured in the AUTOSAR TcpIp configuration. If a SocketOwner is used, a pointer to the TcpIp_<Up>GetSocket must be configured in OSAPI_PortProperty::get_socket. If a SocketOwner is not used, a pointer to a function which can send data must be configured in OSAPI_PortProperty::send_data.

Depending on the DDS discovery configuration, a maximum of 3 UDP sockets are needed for each participant created. All function declarations needed to configure the SocketOwner can be found in the file osapi_os_autosar.h and are:

• NETIO_Autosar_TcpIp_pdu_callout()

• NETIO_Autosar_TcpIp_udp_rx_indication()

It is very important that the on-packet reception function OSAPI_Autosar_TcIp_udp_rx_indication() or NETIO_Autosar_TcpIp_pdu_callout() is called. If there is an OS configuration error, this function might not be called.

It is important to note that the IP address identifier representing the local IP address and the EthIf controller used to bind the socket to can be configured in the property OSAPI_PortProperty::local_addr_id. This should be configured in Elektrobit Tresos as a TCPIP_UNICAST TcpIpAddressType.

It is possible to configure Connext Micro to not use a SocketOwnwer. If a SocketOwner is not used, it is important to configure AUTOSAR such that one of the functions OSAPI_Autosar_TcIp_udp_rx_indication() or NETIO_Autosar_TcpIp_pdu_callout() is called when a UDP packet is received.

Only unicast receive sockets are supported.

It is very important that the TCP/IP interface is running and an IP address is assigned before a DomainParticipant is created, otherwise the DomainParticipant creation might fail because sockets cannot be created.

5.6.2.5. Events

Depending on the configuration, only one event might be used. One event is required by the UDP receive callback to notify the UDP receive task that a UDP packet is available.

The ID of this event can be configured in OSAPI_PortProperty::udp_packet_received_event.

This event is only needed if OSAPI_PortProperty::use_udp_thread is set to TRUE. Please refer to Micro UDP Task for details.

DDS WaitSets require more events; please refer to Semaphores for details.

5.6.2.6. Semaphores

Connext Micro uses semaphores to create WaitSets and to support blocking the UDP receive task if OSAPI_PortProperty::use_udp_thread is TRUE. OSEK and AUTOSAR do not define any semaphore objects. For this reason, semaphores are implemented using events and alarms. For each semaphore, two events and one alarm must be added to the AUTOSAR configuration.

If OSAPI_PortProperty::use_udp_thread is TRUE, one semaphore is needed. This semaphore must use the first event and alarm IDs, and these IDs must be assigned to the UDP Task. Please refer to Micro UDP Task for details.

For each WaitSet, two semaphores are needed.

WaitSet.wait() can be called only from the task that created the WaitSet.

If WaitSets are not used, or if OSAPI_PortProperty::use_udp_thread is FALSE, you do not need to allocate any resources or alarms for semaphores. In this case set the following properties to 0:

• OSAPI_PortProperty::semaphore_max_count

• OSAPI_PortProperty::first_give_event

• OSAPI_PortProperty::first_timeout_event

• OSAPI_PortProperty::first_alarm

The semaphore implementation uses two events and one alarm for each semaphore that is created (a total of four events and two alarms are needed for each WaitSet).

One event, the give event, is set in the OSAPI_Semaphore_give() method. The other event, the timeout event, is used to signal a timeout in the semaphore. The alarm must be configured to set the give event. The OSAPI_Semaphore_take() method starts the alarm and waits for either of the two events to occur.

Give events must have consecutive event IDs, starting at OSAPI_PortProperty::first_give_event (e.g., 1, 2, 4). Timeout events must have consecutive event IDs starting at OSAPI_PortProperty::first_timeout_event (e.g., 8, 16, 32). Alarms must have consecutive IDs starting at OSAPI_PortProperty::first_alarm (e.g., 1, 2, 3). So an alarm with ID 1 must set timeout event 8; alarm ID 2 must set timeout event 16, and so on.

The alarm for semaphore implementation must be configured as ‘RELATIVE’. The counter used to trigger the alarm must be configured with one tick per millisecond. If this is not done properly, the semaphore timeout will occur sooner or later than expected.

5.6.2.7. Memory

Connext Micro uses a buffer for all its memory allocations. The buffer can span across several non-adjacent areas. The number of areas can be configured in OSAPI_PortProperty::number_of_heap_areas. The size required for this buffer depends on the number of DDS entities created and their QoS. The size of each area can be configured in OSAPI_PortProperty::heap_area_size. The start address for each of the areas can be configured in OSAPI_PortProperty::heap_area.

This buffer location and size can be modified, but it is recommended to use a buffer of at least 100 KB.

All allocations within Connext Micro are protected by a critical section. For more information see Critical Sections.

5.6.3. AUTOSAR Port Details

5.6.3.1. Logging

Connext Micro can optionally use the AUTOSAR Det module:

• Set the right log verbosity in Connext Micro by calling OSAPI_Log_set_verbosity(). The default verbosity is OSAPI_LOG_VERBOSITY_ERROR.

• Set the AUTOSAR log display handler by calling OSAPI_Log_set_display_handler(OSAPI_AutosarLog_default_display, NULL). The file osapi_autosar.h contains the declaration of the function OSAPI_AutosarLog_default_display().

• Connext Micro calls Det_ReportError() with the module ID RTIME_DDS_MODULE_ID and the instance ID RTIME_DDS_INSTANCE_ID. These can be found in file osapi_os_autosar.h.

Connext Micro logging can be disabled by adding the following options when compiling with CMake:

• -DRTIME_OSAPI_ENABLE_LOG=Exclude (when compiling on a Windows system, replace the symbol = with _eq_).

If the Connext Micro sources are not compiled with CMake, logging can be disabled by adding the compiler flags OSAPI_ENABLE_TRACE=0 and OSAPI_ENABLE_LOG=0.

The function used to write logs can be configured using the macro OSAPI_LOG_WRITE_BUFFER in the file osapi_os_autosar.h. The default value for this macro is printf(), which on some platforms will write on the serial port. This can be useful for debugging purposes, but it can be slow, causing tasks to have longer execution times than allowed. If this is the case, it is recommended that you disable logging or use a different function by calling OSAPI_AutosarLog_default_display().

5.6.3.2. WaitSets

For each WaitSet that will be created, you need to adjust the configuration to have two semaphores. The semaphore implementation needs two events and one alarm.

A WaitSet wait operation can only be called from the task that created the WaitSet.

Note that events cannot be set for a task that is in the suspended state. As semaphore implementation is based on events, the task that reads all received samples must be running before any sample is received.

5.6.3.3. UDP Automatic Configuration

UDP automatic configuration is not currently supported. See the HelloWorld_static_dpde example to learn how to statically configure the UDP transport.

5.6.4. Compiling

This section explains how to build the Connext Micro source-code for AUTOSAR.

5.6.4.1. Building Connext Micro with rtime-make

The Connext Micro source bundle includes a bash (on Linux and macOS systems) or BAT (on Windows systems) script to simplify the invocation of cmake called rtime-make. These scripts provide a convenient way to invoke cmake with the correct options.

On Linux and macOS systems, the script is located in:

resource/scripts/rtime-make

On Windows systems, the script is located in:

resource\scripts\rtime-make

The following environment variables are needed to compile for an Elektrobit implementation:

• OSEK_TOOLCHAIN_PATH : Path to the toolchain used to compile. E.g., TASKING install folder.

• OSEK_PATH : Path to AUTOSAR implementation installation.

Environment variables example to compile Connext Micro libraries for an Elektrobit AUTOSAR implementation:

• OSEK_TOOLCHAIN_PATH : /c/TASKING/TriCorev6.2r2

• OSEK_PATH : /c/eb

Environment variables example to compile Connext Micro libraries for a Mentor™ implementation:

• OSEK_TOOLCHAIN_PATH : /c/TASKING/TriCorev6.2r2

• OSEK_PATH : /c/AUTOSAR

cmake toolchain files are included to compile Connext Micro for Elektrobit and Mentor AUTOSAR implementations. Example commands to build AUTOSAR libraries:

• Libraries for Elektrobit using a Windows prompt and Unix Makefile generator (that uses Tasking mktc.exe as the make program):

  <path-to-rtime-make>/rtime-make --target Autosar --name tc29xtOsekCoreTasking6.2r2 --build --config Debug -G "Unix Makefiles"</B>
  

• Libraries for Elektrobit using a Windows prompt and a Ninja generator:

  <path-to-rtime-make>/rtime-make --target Autosar --name tc29xtOsekCoreTasking6.2r2 --build --config Debug -G "Ninja"</B>
  

• Libraries for Mentor using MSys and a Unix Makefile generator:

  <path-to-rtime-make>/rtime-make --target Autosar --name tc29xtVSTARTasking6.2r2 --build --config Debug -G "Unix Makefiles"</B>
  

5.6.4.2. Importing the Connext Micro Source Code

Read the general rules for importing the Connext Micro source code in Building the Connext Micro Source.

To build the AUTOSAR port, either define -D__autosar__ or:

• -DOSAPI_OS_DEF_H=”osapi_os_autosar.h”

• -DOSAPI_CC_DEF_H=”osapi_cc_autosar.h”

5.6.5. Interoperability

The Connext Micro AUTOSAR port does not have any additional restrictions regarding interoperability. The same interoperability considerations as for other ports apply to the AUTOSAR port. For more information, please refer to Working with RTI Connext Micro and RTI Connext DDS.

5.6.6. Compiling Applications

When compiling applications for this platform, please note the following in addition to the information in build_environment:

• The type-support code generated with rtiddsgen must be compiled with the Tasking compiler option –integer-enumeration

• If using Tasking v6.2r2 or Tasking v6.2r2p1, do not compile with -O3. This optimization level may introduce errors. This has been fixed in Tasking v6.2r2p2 and later.

• The double type must be compiled with doubles as 8 bytes. That is, do not use the Tasking compiler option to treat doubles as floats.