FreeRTOS on nRF52810

RE: FreeRTOS on nRF52810

yangshuanghua — Tue, 14 May 2019 02:28:57 GMT

great answer very useful !!!

RE: FreeRTOS on nRF52810

stone.xiang — Thu, 31 May 2018 02:29:00 GMT

Hi,

I got these errors when compiling the project within FREE RTOS distributed with nrf52810.

compiling port_cmsis_systick.c...
..\..\..\..\..\..\external\freertos\portable\CMSIS\nrf52\port_cmsis_systick.c(124): error: #20: identifier "NRF_RTC2" is undefined
uint32_t systick_counter = nrf_rtc_counter_get(
ortNRF_RTC_REG);
..\..\..\..\..\..\external\freertos\portable\CMSIS\nrf52\port_cmsis_systick.c(171): error: #20: identifier "NRF_RTC2" is undefined
nrf_rtc_prescaler_set(
ortNRF_RTC_REG, portNRF_RTC_PRESCALER);
..\..\..\..\..\..\external\freertos\portable\CMSIS\nrf52\port_cmsis_systick.c(177): error: #20: identifier "RTC2_IRQn" is undefined
NVIC_SetPriority(
ortNRF_RTC_IRQn, configKERNEL_INTERRUPT_PRIORITY);
..\..\..\..\..\..\external\freertos\portable\CMSIS\nrf52\port_cmsis_systick.c: 0 warnings, 3 errors

Could you please teach me how to solve these problems, I think you may also encountered the same problem.

Kind regards,

THANKS.

RE: FreeRTOS on nRF52810

Susheel Nuguru — Tue, 13 Feb 2018 09:49:43 GMT

you might have to comment this out in port_cmsis.c

static void vPortEnableVFP( void )
{
    //SCB->CPACR |= 0xf << 20;
}

RE: FreeRTOS on nRF52810

Susheel Nuguru — Sun, 11 Feb 2018 13:51:55 GMT

awesome.. thanks for confirming that it worked.

RE: FreeRTOS on nRF52810

Nebojsa_J — Thu, 08 Feb 2018 00:07:20 GMT

Thanks Aryan,

With your input above, I was able to get FreeRtos to run on nRF52810.... with the following additional changes:

* Made the same changes you have above to the corresponding port files for the GCC compiler (since that's what I am using)

* After including the softDevice (running s112) and the FreeRtos files, I ran into a couple of double function definitions that I had to resolve.... One of the double definitions was the "SD_EVT_IRQHandler" function which is in both the nrf_sdh.c and nrf_sdh_frertos.c. Can't remember the other, but it should be obvious if anyone else runs into this....

Again, thanks for your help!!

RE: FreeRTOS on nRF52810

Susheel Nuguru — Tue, 06 Feb 2018 13:20:45 GMT

Nordic FreeRTOS port does not use FPU for anything. All it does is push the FPU context of the task that is using it to the stack when it is starting the scheduler using PendSV interrupt handler. The best would have been to fence under a macro.

Comment out below in port_cmsis.c

#if !(__FPU_USED) && !(__LINT__)
    #error This port can only be used when the project options are configured to enable hardware floating point support.
#endif

replace xPortPendSVHandler in port.c with this

__asm void xPortPendSVHandler( void )
{
    extern uxCriticalNesting;
    extern pxCurrentTCB;
    extern vTaskSwitchContext;

    PRESERVE8

    mrs r0, psp
    isb
    /* Get the location of the current TCB. */
    ldr r3, =pxCurrentTCB
    ldr r2, [r3]

    /* Is the task using the FPU context?  If so, push high vfp registers. */
#if (__FPU_PRESENT == 1U) && (__FPU_USED == 1U)
    tst r14, #0x10
    it eq
    vstmdbeq r0!, {s16-s31}
#endif
    
    /* Save the core registers. */
    stmdb r0!, {r4-r11, r14}

    /* Save the new top of stack into the first member of the TCB. */
    str r0, [r2]

    stmdb sp!, {r3}
    mov r0, #(configMAX_SYSCALL_INTERRUPT_PRIORITY << (8 - configPRIO_BITS))
    msr basepri, r0
    dsb
    isb
    bl vTaskSwitchContext
    mov r0, #0
    msr basepri, r0
    ldmia sp!, {r3}

    /* The first item in pxCurrentTCB is the task top of stack. */
    ldr r1, [r3]
    ldr r0, [r1]

    /* Pop the core registers. */
    ldmia r0!, {r4-r11, r14}

    /* Is the task using the FPU context?  If so, pop the high vfp registers
    too. */
#if (__FPU_PRESENT == 1U) && (__FPU_USED == 1U)
    tst r14, #0x10
    it eq
    vldmiaeq r0!, {s16-s31}
#endif
    msr psp, r0
    isb

    bx r14

    ALIGN
}

The rest of the port is independent of FPU. This should work, given that you have enough space in that chip to run freertos and your appliction

RE: FreeRTOS on nRF52810

Nebojsa_J — Thu, 01 Feb 2018 22:44:14 GMT

Thanks @RK...

I think this info confirms that the FreeRTOS port will not work for nRF52810 as is in SDK14.2.... If anyone has pointers on how to fix this, please share the wisdom.. :) It will be appreciated.

RE: FreeRTOS on nRF52810

RK — Thu, 01 Feb 2018 21:33:59 GMT

I don't think so - I get that from

devzone.nordicsemi.com/.../110729

that thread which discussed disabling FPU on FreeRTOS on the nRF52840. The port used was the M4 port which naturally comes with FPU support enabled. This ought not to be that hard to fix yourself but I don't think the Nordic port out of the box will work for you.