BOOSTXL-CC3135: Porting query : iMX RT1052 FreeRTOS

Hi Aniket,

For an example of porting the CC3135 host driver to FreeRTOS, I suggest you take a look at the FreeRTOS port in the SimpleLink SDK Wi-Fi plugin:https://www.ti.com/tool/download/SIMPLELINK-SDK-WIFI-PLUGIN

This plugin has a port of the host driver to the MSP432 platforms, and supports FreeRTOS in addition to TIRTOS. This support is done through a POSIX layer that is implemented in the MSP432 SDK: https://www.ti.com/tool/download/SIMPLELINK-MSP432-SDK

Regards,
Michael

Hi Michael,

We are already referring both the plugins that you have suggested.

But the FreeRTOS is supported through POSIX. In our case we do not use POSIX.

We have implemented all the functions for OS Adaptaion layer, but have doubt regarding our implementation of sl_SyncObjCreate.

Could you provide suggestions regarding the sl_SyncObjCreate code implemetation ?

Regards,

Aniket.

Hi Michael,

Is there any update regarding sl_SyncObjCreate code implemetation in plain freeRTOS?

Regards,

Aniket.

Hi Aniket,

For the POSIX functions, the SimpleLink SDKs should have a porting file that translate a given POSIX call to plain freeRTOS. For example, the sem_init() function that is used within the host driver port provided in the SmipleLink Wi-Fi plugin is defined like so:

int sem_init(sem_t *semaphore, int pshared, unsigned value)
{
    sem_obj *obj = (sem_obj*)(&semaphore->freertos);

    /* TODO object size validation */
//  assert(sizeof(sem_obj) <= sizeof(sem_t));

    if (value > SEM_VALUE_MAX) {
        errno = EINVAL;
        return (-1);
    }

    /*  FreeRTOS xSemaphoreCreateCounting() creates a queue of
     *  length maxCount, where maxCount is the maximum count that
     *  the semaphore should ever reach.  It looks like this should be
     *  ok since the item length for a semaphore queue is 0, so the
     *  memory allocated is not dependent on maxCount.
     */
    obj->sem = xSemaphoreCreateCounting((UBaseType_t)SEM_VALUE_MAX,
            (UBaseType_t)value);

    if (obj->sem == NULL) {
        errno = ENOSPC;
        return (-1);
    }

    return (0);
}

The full implementations of all POSIX to FreeRTOS functions can be found in /source/ti/posix/freertos/ of the MSP432 SDK.

Alternatively, you can look at the implementations of the source driver functions from the DPL. In user.h an alternative for sl_SyncObjCreate() is SemaphoreP_create_handle(). It is defined in plain FreeRTOS in kernel/freertos/dpl/SemaphoeP_freertos.c:

/*
 *  ======== SemaphoreP_construct ========
 */
SemaphoreP_Handle SemaphoreP_construct(SemaphoreP_Struct *handle,
    unsigned int count, SemaphoreP_Params *params)
{
    SemaphoreHandle_t sem = NULL;

#if (configSUPPORT_STATIC_ALLOCATION == 1)
    SemaphoreP_Params semParams;
    if (params == NULL) {
        params = &semParams;
        SemaphoreP_Params_init(params);
    }

    if (params->mode == SemaphoreP_Mode_COUNTING) {
#if (configUSE_COUNTING_SEMAPHORES == 1)
        /*
         *  The size of the semaphore queue is not dependent on MAXCOUNT.
         *
         *  FreeRTOS xSemaphoreCreateCounting() appears from the
         *  code in xQueueCreateCountingSemaphore() to create
         *  a queue of length maxCount, where maxCount is the
         *  maximum count that the semaphore should ever reach.
         *  However, the queue item size (queueSEMAPHORE_QUEUE_ITEM_LENGTH),
         *  is 0, so no actual memoory is allocated for the queue items.
         *  Therefore we can pass any non-zero number as the maximum
         *  semaphore count.
         */
        sem = xSemaphoreCreateCountingStatic((UBaseType_t)MAXCOUNT,
                (UBaseType_t)count, (StaticSemaphore_t *)handle);
#endif
    }
    else {
        sem = xSemaphoreCreateBinaryStatic((StaticSemaphore_t *)handle);
        if ((sem != NULL) && (count != 0)) {
            xSemaphoreGive(sem);
        }
    }
#endif

    return ((SemaphoreP_Handle)sem);
}

I suggest you look at the POSIX to FreeRTOS abstraction layer porting files in the MSP432 SDK for more porting details.

Regards,

Michael

Hi Michael,

Thanks for reply. 

I noticed that SemaphoreP_create_handle() is used as alternative when SL_PLATFORM_MULTI_THREADED is NOT defined.

While using FreeRTOS on iMX RT1052, what is your recommendation regarding SL_PLATFORM_MULTI_THREADED ? should it be defined or not.

Regards,

Aniket.

Hi Aniket,

SL_PLATFORM_MULTI_THREADED should be defined if you are using FreeRTOS.

Regards,

Michael