README.md

Fx_NoR_Write_Read_File application description

This application provides an example of Azure RTOS FileX and LevelX stacks usage on STM32F469I-Discovery board, it demonstrates how to create a Fat File system on the NOR flash using FileX alongside LevelX. The application is designed to execute file operations on the N25Q128A NOR flash device, the code provides all required software code for properly managing it.

The application starts by calling the ThreadX's initialization routine which executes the main thread that handles file operations. At this stage, all FileX resources are created, the N25Q128A driver is initialized and a single thread is created:

• fx_thread (Prio : 10; PreemptionPrio : 10) used for file operations.

The fx_thread will start by formatting the NOR Flash using FileX services. The resulting file system is a FAT32 compatible, with 512 bytes per sector and 8 sectors per cluster. Optionally, the NOR flash can be erased prior to format, this allows LevelX and FileX to create a clean FAT FileSystem.

Chip erase operation takes considerable time to finish whole flash reset, therefore it is disabled by default. To enable it, please set the following flags in "lx_stm32_qspi_driver.h":

• LX_STM32_QSPI_ERASE
• LX_STM32_QSPI_INIT

Upon successful opening of the flash media, FileX continue with creating a file called "STM32.TXT" into the root directory, then write into it some dummy data. Then file is re-opened in read only mode and content is checked.

Through all the steps, FileX/LevelX services are called to print the flash size available before and after the example file is written into the flash. The number of occupied sectors is also shown.

Note

• The provided HAL Polling based implementation for QuadSPI component N25Q128A, assumes the following settings are set:

  QuadSPI Mode: Bank1 with QuadSPI Lines ClockPrescaler = 1; FifoThreshold = 1; SampleShifting = QSPI_SAMPLE_SHIFTING_HALFCYCLE; FlashSize = 23; ChipSelectHighTime = QSPI_CS_HIGH_TIME_5_CYCLE; ClockMode = QSPI_CLOCK_MODE_0; FlashID = QSPI_FLASH_ID_1; DualFlash = QSPI_DUALFLASH_DISABLE;

  Different configuration can be used but need to be reflected in the implementation guarded with QSPI_HAL_CFG_xxx user tags.

Expected success behavior

Successful operation is marked by a toggeling green LED light.

Also, information regarding the total and available size of the flash media is printed to the serial port.

Error behaviors

On failure, the red LED starts toggling while the green LED is switched OFF.

• Error handler is called at the spot where the error occurred.

Assumptions if any

None

Known limitations

None

ThreadX usage hints

• ThreadX uses the Systick as time base, thus it is mandatory that the HAL uses a separate time base through the TIM IPs.

• ThreadX is configured with 100 ticks/sec by default, this should be taken into account when using delays or timeouts at application. It is always possible to reconfigure it in the "tx_user.h", the "TX_TIMER_TICKS_PER_SECOND" define,but this should be reflected in "tx_initialize_low_level.s" file too.

• ThreadX is disabling all interrupts during kernel start-up to avoid any unexpected behavior, therefore all system related calls (HAL, BSP) should be done either at the beginning of the application or inside the thread entry functions.

• ThreadX offers the "tx_application_define()" function, that is automatically called by the tx_kernel_enter() API. It is highly recommended to use it to create all applications ThreadX related resources (threads, semaphores, memory pools...) but it should not in any way contain a system API call (HAL or BSP).

• Using dynamic memory allocation requires to apply some changes to the linker file. ThreadX needs to pass a pointer to the first free memory location in RAM to the tx_application_define() function, using the "first_unused_memory" argument. This require changes in the linker files to expose this memory location.

  • For EWARM add the following section into the .icf file:

  place in RAM_region    { last section FREE_MEM };
  

  • For MDK-ARM:

  either define the RW_IRAM1 region in the ".sct" file
  or modify the line below in "tx_low_level_initilize.s to match the memory region being used
      LDR r1, =|Image$$RW_IRAM1$$ZI$$Limit|
  

  • For STM32CubeIDE add the following section into the .ld file:

  ._threadx_heap :
    {
       . = ALIGN(8);
       __RAM_segment_used_end__ = .;
       . = . + 64K;
       . = ALIGN(8);
     } >RAM_D1 AT> RAM_D1
  

  The simplest way to provide memory for ThreadX is to define a new section, see ._threadx_heap above.
  In the example above the ThreadX heap size is set to 64KBytes.
  The ._threadx_heap must be located between the .bss and the ._user_heap_stack sections in the linker script.	 
  Caution: Make sure that ThreadX does not need more than the provided heap memory (64KBytes in this example).	 
  Read more in STM32CubeIDE User Guide, chapter: "Linker script".
  

  • The "tx_initialize_low_level.s" should be also modified to enable the "USE_DYNAMIC_MEMORY_ALLOCATION" flag.

FileX/LevelX usage hints

• When calling the fx_media_format() API, it is highly recommended to understand all the parameters used by the API to correctly generate a valid filesystem.

Keywords

RTOS, ThreadX, FileX, LevelX, File System, NOR, QUADSPI, FAT32

Hardware and Software environment

• This application runs on STM32F469xx devices.

• This application has been tested with STMicroelectronics STM32F469I-Discovery boards Revision: MB1189 B-03. and can be easily tailored to any other supported device and development board.

• This application uses USART3 to display logs, the hyperterminal configuration is as follows:

  • BaudRate = 115200 baud
  • Word Length = 8 Bits
  • Stop Bit = 1
  • Parity = none
  • Flow control = None

How to use it ?

In order to make the program work, you must do the following :

• Open your preferred toolchain
• Rebuild all files and load your image into target memory
• Run the application