STM32U585 TrustZone ADC DMA-buffer always 0

[AAArdvark]

Hi, I'm using 3 channels of ADC4 with GPDMA1 (channel 4) in secure world of a TrustZone-project and the DMA-buffer stays always 0. The same ADC/DMA-configuration with the same application code (all mnus the security aspects) are working fine without TrustZone on the same hardware. I set the DMA-channel and the ADC-channel to secure and privileged, also the SAU-configuration for these peripherals is secure, the DMA-interrupt (circular) is triggered and calling HAL_ADC_ConvCpltCallback but there's nothing inside the DMA-buffer (which is defined as volatile inside a secure and privileged SRAM-area). I've tried different ADC conversion rates, clock rates and clock sources, checked for errors (especially overruns) and secure faults (with GTZC), there's absolutely nothing. I guess it must have something to do with secure/privileged areas or peripherals but since all the parts are secure and privileged I don't know what it could be. I'd be thankful for any suggestions; here is my ADC DMA-initialization code:

void MX_ADC4_Init(void)
{

  /* USER CODE BEGIN ADC4_Init 0 */

  /* USER CODE END ADC4_Init 0 */

  ADC_ChannelConfTypeDef sConfig = {0};

  /* USER CODE BEGIN ADC4_Init 1 */

  /* USER CODE END ADC4_Init 1 */

  /** Common config
  */
  hadc4.Instance = ADC4;
  hadc4.Init.ClockPrescaler = ADC_CLOCK_ASYNC_DIV64;
  hadc4.Init.Resolution = ADC_RESOLUTION_12B;
  hadc4.Init.DataAlign = ADC_DATAALIGN_RIGHT;
  hadc4.Init.ScanConvMode = ADC4_SCAN_ENABLE;
  hadc4.Init.EOCSelection = ADC_EOC_SEQ_CONV;
  hadc4.Init.LowPowerAutoPowerOff = ADC_LOW_POWER_NONE;
  hadc4.Init.LowPowerAutoWait = DISABLE;
  hadc4.Init.ContinuousConvMode = ENABLE;
  hadc4.Init.NbrOfConversion = 3;
  hadc4.Init.ExternalTrigConv = ADC_SOFTWARE_START;
  hadc4.Init.ExternalTrigConvEdge = ADC_EXTERNALTRIGCONVEDGE_NONE;
  hadc4.Init.DMAContinuousRequests = ENABLE;
  hadc4.Init.TriggerFrequencyMode = ADC_TRIGGER_FREQ_HIGH;
  hadc4.Init.Overrun = ADC_OVR_DATA_OVERWRITTEN;
  hadc4.Init.SamplingTimeCommon1 = ADC4_SAMPLETIME_7CYCLES_5;
  hadc4.Init.SamplingTimeCommon2 = ADC4_SAMPLETIME_1CYCLE_5;
  hadc4.Init.OversamplingMode = ENABLE;
  hadc4.Init.Oversampling.Ratio = ADC_OVERSAMPLING_RATIO_2;
  hadc4.Init.Oversampling.RightBitShift = ADC_RIGHTBITSHIFT_1;
  hadc4.Init.Oversampling.TriggeredMode = ADC_TRIGGEREDMODE_SINGLE_TRIGGER;
  if (HAL_ADC_Init(&hadc4) != HAL_OK)
  {
    Error_Handler();
  }

  /** Configure Regular Channel
  */
  sConfig.Channel = ADC_CHANNEL_9;
  sConfig.Rank = ADC4_REGULAR_RANK_1;
  sConfig.SamplingTime = ADC4_SAMPLINGTIME_COMMON_1;
  sConfig.OffsetNumber = ADC_OFFSET_NONE;
  sConfig.Offset = 0;
  if (HAL_ADC_ConfigChannel(&hadc4, &sConfig) != HAL_OK)
  {
    Error_Handler();
  }

  /** Configure Regular Channel
  */
  sConfig.Channel = ADC_CHANNEL_10;
  sConfig.Rank = ADC4_REGULAR_RANK_2;
  if (HAL_ADC_ConfigChannel(&hadc4, &sConfig) != HAL_OK)
  {
    Error_Handler();
  }

  /** Configure Regular Channel
  */
  sConfig.Channel = ADC_CHANNEL_11;
  sConfig.Rank = ADC4_REGULAR_RANK_3;
  if (HAL_ADC_ConfigChannel(&hadc4, &sConfig) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN ADC4_Init 2 */

  /* USER CODE END ADC4_Init 2 */

}

void HAL_ADC_MspInit(ADC_HandleTypeDef* adcHandle)
{

  GPIO_InitTypeDef GPIO_InitStruct = {0};
  DMA_NodeConfTypeDef NodeConfig= {0};
  RCC_PeriphCLKInitTypeDef PeriphClkInit = {0};
  if(adcHandle->Instance==ADC4)
  {
  /* USER CODE BEGIN ADC4_MspInit 0 */

  /* USER CODE END ADC4_MspInit 0 */

  /** Initializes the peripherals clock
  */
    PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_ADCDAC;
    PeriphClkInit.AdcDacClockSelection = RCC_ADCDACCLKSOURCE_HCLK;
    if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit) != HAL_OK)
    {
      Error_Handler();
    }

    /* ADC4 clock enable */
    __HAL_RCC_ADC4_CLK_ENABLE();

    __HAL_RCC_GPIOA_CLK_ENABLE();
    /**ADC4 GPIO Configuration
    PA4     ------> ADC4_IN9
    PA5     ------> ADC4_IN10
    PA6     ------> ADC4_IN11
    */
    GPIO_InitStruct.Pin = GPIO_PIN_4|GPIO_PIN_5|GPIO_PIN_6;
    GPIO_InitStruct.Mode = GPIO_MODE_ANALOG;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

    /* ADC4 DMA Init */
    /* GPDMA1_REQUEST_ADC4 Init */
    NodeConfig.NodeType = DMA_GPDMA_LINEAR_NODE;
    NodeConfig.SrcSecure = DMA_CHANNEL_SRC_SEC;
    NodeConfig.DestSecure = DMA_CHANNEL_DEST_SEC;
    NodeConfig.Init.Request = GPDMA1_REQUEST_ADC4;
    NodeConfig.Init.BlkHWRequest = DMA_BREQ_SINGLE_BURST;
    NodeConfig.Init.Direction = DMA_PERIPH_TO_MEMORY;
    NodeConfig.Init.SrcInc = DMA_SINC_FIXED;
    NodeConfig.Init.DestInc = DMA_DINC_INCREMENTED;
    NodeConfig.Init.SrcDataWidth = DMA_SRC_DATAWIDTH_HALFWORD;
    NodeConfig.Init.DestDataWidth = DMA_DEST_DATAWIDTH_HALFWORD;
    NodeConfig.Init.SrcBurstLength = 1;
    NodeConfig.Init.DestBurstLength = 1;
    NodeConfig.Init.TransferAllocatedPort = DMA_SRC_ALLOCATED_PORT0|DMA_DEST_ALLOCATED_PORT0;
    NodeConfig.Init.TransferEventMode = DMA_TCEM_BLOCK_TRANSFER;
    NodeConfig.Init.Mode = DMA_NORMAL;
    NodeConfig.TriggerConfig.TriggerPolarity = DMA_TRIG_POLARITY_MASKED;
    NodeConfig.DataHandlingConfig.DataExchange = DMA_EXCHANGE_NONE;
    NodeConfig.DataHandlingConfig.DataAlignment = DMA_DATA_RIGHTALIGN_ZEROPADDED;
    NodeConfig.SrcSecure = DMA_CHANNEL_SRC_SEC;
    NodeConfig.DestSecure = DMA_CHANNEL_DEST_SEC;
    if (HAL_DMAEx_List_BuildNode(&NodeConfig, &Node_GPDMA1_Channel4) != HAL_OK)
    {
      Error_Handler();
    }

    if (HAL_DMAEx_List_InsertNode(&List_GPDMA1_Channel4, NULL, &Node_GPDMA1_Channel4) != HAL_OK)
    {
      Error_Handler();
    }

    if (HAL_DMAEx_List_SetCircularMode(&List_GPDMA1_Channel4) != HAL_OK)
    {
      Error_Handler();
    }

    handle_GPDMA1_Channel4.Instance = GPDMA1_Channel4;
    handle_GPDMA1_Channel4.InitLinkedList.Priority = DMA_LOW_PRIORITY_LOW_WEIGHT;
    handle_GPDMA1_Channel4.InitLinkedList.LinkStepMode = DMA_LSM_FULL_EXECUTION;
    handle_GPDMA1_Channel4.InitLinkedList.LinkAllocatedPort = DMA_LINK_ALLOCATED_PORT0;
    handle_GPDMA1_Channel4.InitLinkedList.TransferEventMode = DMA_TCEM_BLOCK_TRANSFER;
    handle_GPDMA1_Channel4.InitLinkedList.LinkedListMode = DMA_LINKEDLIST_CIRCULAR;
    if (HAL_DMAEx_List_Init(&handle_GPDMA1_Channel4) != HAL_OK)
    {
      Error_Handler();
    }

    if (HAL_DMAEx_List_LinkQ(&handle_GPDMA1_Channel4, &List_GPDMA1_Channel4) != HAL_OK)
    {
      Error_Handler();
    }

    __HAL_LINKDMA(adcHandle, DMA_Handle, handle_GPDMA1_Channel4);

    if (HAL_DMA_ConfigChannelAttributes(&handle_GPDMA1_Channel4, DMA_CHANNEL_PRIV|DMA_CHANNEL_SEC) != HAL_OK)
    {
      Error_Handler();
    }

    /* ADC4 interrupt Init */
    HAL_NVIC_SetPriority(ADC4_IRQn, 5, 0);
    HAL_NVIC_EnableIRQ(ADC4_IRQn);
  /* USER CODE BEGIN ADC4_MspInit 1 */

  /* USER CODE END ADC4_MspInit 1 */
  }
}

void MX_GPDMA1_Init(void)
{
  /* Peripheral clock enable */
  __HAL_RCC_GPDMA1_CLK_ENABLE();

  /* GPDMA1 interrupt Init */
    HAL_NVIC_SetPriority(GPDMA1_Channel4_IRQn, 4, 0);
    HAL_NVIC_EnableIRQ(GPDMA1_Channel4_IRQn);
}