# FreeRTOS+FAT ramdisk creation on Nucleo-L476RG **URL:** \ **Category:** Kernel\ **Created:** [June 4, 2017, 7:48am UTC](https://forums.freertos.org/t/freertos-fat-ramdisk-creation-on-nucleo-l476rg/6592 "2017-06-04T07:48:46Z")\ **Posts on this page:** 15\ **Page:** 1
**Author:** ![system](https://d2v6vdsk2p900z.cloudfront.net/original/1X/7fc8fdb729c645aab5b20282bbe34e57cb407be6.jpeg) [@system](https://forums.freertos.org/u/system)\ **Post date:** [June 4, 2017, 7:48am UTC](https://forums.freertos.org/t/freertos-fat-ramdisk-creation-on-nucleo-l476rg/6592/1 "2017-06-04T07:48:46Z")
**[sachingole](https://sourceforge.net/u/sachingole/)** wrote on [Sunday, June 04, 2017](https://sourceforge.net/p/freertos/discussion/382005/thread/59ac4be5/#5a00): Hi All, I have Nucleo-L476RG development board, I am able to run FreeRTOS 8.2.3 version on it. LED blinking code works good as expected. I have integrated FreeRTOS v8.2.3 + FAT inside my source, build is sucessful. For one of my use case I need ramdisk file system with few KB size. This board processor has 128KB SRAM and 1MB flash(code size), Currently I am trying to create ramdisk with size 75KB, I am getting following error. **FF\_Format: Secs 142 Rsvd 1 Hidden 8 Root 32 Data 109 FF\_Format: Can not make a FAT16 (tried 16) with 142 sectors** Can any help me to resolve following queries :- **1. Is it posible to create ramdisk with this much low size like 50KB or 75KB ? 2. any suggestion to create ramdisk with this much low SRAM. 3. Any significance form numbers from above error.** Reason to create ramdisk, one of my use case need file system and for this board there is no any another way to get memory like SD card or increase memory. Thanks in advance for reply. Best regards, Sachin ---
**Author:** ![htibosch](https://d3iykfbgfh8zhg.cloudfront.net/user_avatar/forums.freertos.org/htibosch/32/62_2.png) [@htibosch](https://forums.freertos.org/u/htibosch)\ **Post date:** [June 4, 2017, 8:21am UTC](https://forums.freertos.org/t/freertos-fat-ramdisk-creation-on-nucleo-l476rg/6592/2 "2017-06-04T08:21:54Z")
**[heinbali01](https://sourceforge.net/u/heinbali01/)** wrote on [Sunday, June 04, 2017](https://sourceforge.net/p/freertos/discussion/382005/thread/59ac4be5/#12fd): Sachin, sure it is possible to have a very small volume. You have to overrule the MS standards though, which define the minimum amount of clusters for FAT16 ( or FAT32 ). ```auto #ifdef ffconfigMIN_CLUSTERS_FAT32 #define MIN_CLUSTER_COUNT_FAT32 ffconfigMIN_CLUSTERS_FAT32 #else #define MIN_CLUSTER_COUNT_FAT32 ( 65525 ) #endif #ifdef ffconfigMIN_CLUSTERS_FAT16 #define MIN_CLUSTERS_FAT16 ffconfigMIN_CLUSTERS_FAT16 #else #define MIN_CLUSTERS_FAT16 ( 4085 + 1 ) #endif ``` Have a try with FAT16 and define `ffconfigMIN_CLUSTERS_FAT16` very low: ```auto #define ffconfigMIN_CLUSTERS_FAT16 32 ``` Within `ff_ramdisk.c` you might want to decrease `ramHIDDEN_SECTOR_COUNT`, I think that zero should work. Also, for FAT16, you will have a root directory which can contain up to 512 entries. Not sure if you need that many? ```auto ucFATType = FF_T_FAT16; iFAT32RootClusters = 0; ulFATReservedSectors = 1u; iFAT16RootSectors = 32; /* to get 512 dir entries */ ``` You could make `iFAT16RootSectors` lower, and `ulFATReservedSectors` as zero. Please report back, good luck! ---
**Author:** ![system](https://d2v6vdsk2p900z.cloudfront.net/original/1X/7fc8fdb729c645aab5b20282bbe34e57cb407be6.jpeg) [@system](https://forums.freertos.org/u/system)\ **Post date:** [June 4, 2017, 10:36pm UTC](https://forums.freertos.org/t/freertos-fat-ramdisk-creation-on-nucleo-l476rg/6592/3 "2017-06-04T22:36:37Z")
**[sachingole](https://sourceforge.net/u/sachingole/)** wrote on [Sunday, June 04, 2017](https://sourceforge.net/p/freertos/discussion/382005/thread/59ac4be5/#270f): Thank you Hein, This reply motivated me to try further and get it done. Thanks once again. Changes which I have done :- 1. I have declared below line in ff\_format.c ```auto #define ffconfigMIN_CLUSTERS_FAT16 32 ``` 1. I have declared below line in ff\_ramdisk.c ```auto #define ramHIDDEN_SECTOR_COUNT 0 ``` 1. I have done below changes in ff\_ramdisk.c ```auto ucFATType = FF_T_FAT16; iFAT32RootClusters = 0; ulFATReservedSectors = 0; iFAT16RootSectors = 8; ``` With above changes, Looks like partition creation is successful. Please see below logs :- ```auto ffconfigMIN_CLUSTERS_FAT16 = 32 FF_Format: Secs 150 Rsvd 0 Hidden 0 Root 8 Data 142 FF_Format: SecCluster 1 DatSec 140 DataClus 140 ulClusterBeginLBA 2 FF_Format: Clearing entire FAT (2 x 1 sectors): FF_Format: Clearing done FF_Format: Clearing root directory at 00000002: 8 sectors FF_RAMDiskInit: FF_Format: FF_PartitionSearch: [F8,FF] No signature (00 00), no PBR neither FF_RAMDiskInit: FF_Mount: Reading FAT and calculating Free Space pxIOManager->xPartition.ucType = 0 ``` Then looks like it failed in function ```auto FF_RAMDiskShowPartition( pxRAMDisk ); ``` Then flow goes to function and looks like pxIOManager-\>xPartition.ucType = 0 so it goes in case default: pcTypeName = “UNKOWN”; break; Note : pxIOManager-\>xPartition.ucType value printed above. When debugged further looks like it is going further function is ```auto FF_GetFreeSize( pxIOManager, &xError ); ``` Further debugging take to next fuction ```auto pxIOManager->xPartition.ulFreeClusterCount = FF_CountFreeClusters( pxIOManager, &xError ); ``` control is getting blocked inside this function, It doesnt come out of this. Any suggestion what could be missing. ---
**Author:** ![system](https://d2v6vdsk2p900z.cloudfront.net/original/1X/7fc8fdb729c645aab5b20282bbe34e57cb407be6.jpeg) [@system](https://forums.freertos.org/u/system)\ **Post date:** [June 4, 2017, 10:47pm UTC](https://forums.freertos.org/t/freertos-fat-ramdisk-creation-on-nucleo-l476rg/6592/4 "2017-06-04T22:47:30Z")
**[sachingole](https://sourceforge.net/u/sachingole/)** wrote on [Sunday, June 04, 2017](https://sourceforge.net/p/freertos/discussion/382005/thread/59ac4be5/#29da): Further debugging inside FF\_CountFreeClusters( pxIOManager, &xError ); function, control gets blocked in below line :- ```auto FF_LockFAT( pxIOManager ); ``` From below code snippet. ```auto BaseType_t xTakeLock = FF_Has_Lock( pxIOManager, FF_FAT_LOCK ) == pdFALSE; if( xTakeLock ) { FF_LockFAT( pxIOManager ); } ``` Please could help to verify and suggest workaround, seems like variable lock synchronisation issue. ---
**Author:** ![htibosch](https://d3iykfbgfh8zhg.cloudfront.net/user_avatar/forums.freertos.org/htibosch/32/62_2.png) [@htibosch](https://forums.freertos.org/u/htibosch)\ **Post date:** [June 5, 2017, 4:02am UTC](https://forums.freertos.org/t/freertos-fat-ramdisk-creation-on-nucleo-l476rg/6592/5 "2017-06-05T04:02:16Z")
**[heinbali01](https://sourceforge.net/u/heinbali01/)** wrote on [Monday, June 05, 2017](https://sourceforge.net/p/freertos/discussion/382005/thread/59ac4be5/#4017): Sachin, could you try with again with `ulFATReservedSectors = 1` again? About the lock synchronisation: is the kernel running when you create/mount the RAM-disk? That is necessary because the locking mechanism uses event groups. I know there was a locking-related issue with `FF_IncreaseFreeClusters()`. Here is a patch for ‘ff\_ioman.c’, around line 1703 : ```auto if( pxIOManager->xPartition.ulLastFreeCluster == 0 ) { + BaseType_t xTakeLock = FF_Has_Lock( pxIOManager, FF_FAT_LOCK ) == pdFALSE; - FF_LockFAT( pxIOManager ); + if( xTakeLock ) + { + FF_LockFAT( pxIOManager ); + } { /* Find the an available cluster. */ pxIOManager->xPartition.ulLastFreeCluster = FF_FindFreeCluster( pxIOManager, &xError, pdFALSE ); } - FF_UnlockFAT( pxIOManager ); + if( xTakeLock ) + { + FF_UnlockFAT( pxIOManager ); + } if( FF_isERR( xError ) ) { break; } } ``` Regards ---
**Author:** ![system](https://d2v6vdsk2p900z.cloudfront.net/original/1X/7fc8fdb729c645aab5b20282bbe34e57cb407be6.jpeg) [@system](https://forums.freertos.org/u/system)\ **Post date:** [June 5, 2017, 5:21am UTC](https://forums.freertos.org/t/freertos-fat-ramdisk-creation-on-nucleo-l476rg/6592/6 "2017-06-05T05:21:44Z")
**[sachingole](https://sourceforge.net/u/sachingole/)** wrote on [Monday, June 05, 2017](https://sourceforge.net/p/freertos/discussion/382005/thread/59ac4be5/#945b): Thanks Hein for reply. I have tried following changes, seems still we have some issue. 1. I have done below changes in ff\_ramdisk.c ```auto ulFATReservedSectors = 1u; ``` 1. above mentioned patch added in ff\_ioman.c Following are logs :- FF\_Partition: ffconfigMIN\_CLUSTERS\_FAT16 = 32 FF\_Format: Secs 150 Rsvd 1 Hidden 0 Root 8 Data 141 FF\_Format: SecCluster 1 DatSec 139 DataClus 139 ulClusterBeginLBA 3 FF\_Format: Clearing entire FAT (2 x 1 sectors): FF\_Format: Clearing done FF\_Format: Clearing root directory at 00000003: 8 sectors FF\_RAMDiskInit: FF\_Format: FF\_Part: no partitions, try as PBR ---
**Author:** ![system](https://d2v6vdsk2p900z.cloudfront.net/original/1X/7fc8fdb729c645aab5b20282bbe34e57cb407be6.jpeg) [@system](https://forums.freertos.org/u/system)\ **Post date:** [June 5, 2017, 5:35am UTC](https://forums.freertos.org/t/freertos-fat-ramdisk-creation-on-nucleo-l476rg/6592/7 "2017-06-05T05:35:38Z")
**[sachingole](https://sourceforge.net/u/sachingole/)** wrote on [Monday, June 05, 2017](https://sourceforge.net/p/freertos/discussion/382005/thread/59ac4be5/#a4d7): After debugging further I can see that I got stuck in following function. ```auto FF_Error_t FF_Mount( FF_Disk_t *pxDisk, BaseType_t xPartitionNumber ) ``` Stuck at below line ```auto pxPartition->ulLastFreeCluster = FF_FindFreeCluster( pxIOManager, &xError, pdFALSE ); ``` Which is inside these locks, seems again similar to above lock synchronisation issue. ```auto FF_LockFAT( pxIOManager ); { /* The parameter 'pdFALSE' means: do not claim the free cluster found. */ pxPartition->ulLastFreeCluster = FF_FindFreeCluster( pxIOManager, &xError, pdFALSE ); } FF_UnlockFAT( pxIOManager ); ``` ---
**Author:** ![system](https://d2v6vdsk2p900z.cloudfront.net/original/1X/7fc8fdb729c645aab5b20282bbe34e57cb407be6.jpeg) [@system](https://forums.freertos.org/u/system)\ **Post date:** [June 5, 2017, 5:41am UTC](https://forums.freertos.org/t/freertos-fat-ramdisk-creation-on-nucleo-l476rg/6592/8 "2017-06-05T05:41:15Z")
**[sachingole](https://sourceforge.net/u/sachingole/)** wrote on [Monday, June 05, 2017](https://sourceforge.net/p/freertos/discussion/382005/thread/59ac4be5/#2730): After debugging inside this function. ```auto uint32_t FF_FindFreeCluster( FF_IOManager_t *pxIOManager, FF_Error_t *pxError, BaseType_t xDoClaim ) ``` Control stuck at line no 1102 inside file ff\_fat.c which is as below ```auto FF_LockFAT( pxIOManager ); ``` ---
**Author:** ![htibosch](https://d3iykfbgfh8zhg.cloudfront.net/user_avatar/forums.freertos.org/htibosch/32/62_2.png) [@htibosch](https://forums.freertos.org/u/htibosch)\ **Post date:** [June 5, 2017, 5:59am UTC](https://forums.freertos.org/t/freertos-fat-ramdisk-creation-on-nucleo-l476rg/6592/9 "2017-06-05T05:59:49Z")
**[heinbali01](https://sourceforge.net/u/heinbali01/)** wrote on [Monday, June 05, 2017](https://sourceforge.net/p/freertos/discussion/382005/thread/59ac4be5/#1cae): 1. Are you calling `FF_Mount()`directly or do you use `FF_RAMDiskInit()`? 2. Is your scheduler running when you create the RAM-disk? ---
**Author:** ![system](https://d2v6vdsk2p900z.cloudfront.net/original/1X/7fc8fdb729c645aab5b20282bbe34e57cb407be6.jpeg) [@system](https://forums.freertos.org/u/system)\ **Post date:** [June 5, 2017, 6:28am UTC](https://forums.freertos.org/t/freertos-fat-ramdisk-creation-on-nucleo-l476rg/6592/10 "2017-06-05T06:28:29Z")
**[sachingole](https://sourceforge.net/u/sachingole/)** wrote on [Monday, June 05, 2017](https://sourceforge.net/p/freertos/discussion/382005/thread/59ac4be5/#e126): Hi Hein, 1. I have below function flow, FF\_RAMDiskInit() internally calls FF\_Mount() ```auto /* Create the RAM disk used by the FTP and HTTP servers. */ prvCreateDiskAndExampleFiles(); ``` Inside this it is calling ```auto /* Create the RAM disk. */ pxRAMDisk = FF_RAMDiskInit( mainRAM_DISK_NAME, ucRAMDisk, mainRAM_DISK_SECTORS, mainIO_MANAGER_CACHE_SIZE ); ``` Inside this it calls ```auto xError = prvPartitionAndFormatDisk( pxDisk ); ``` Then it comes to ```auto /* Mount the partition. */ xError = FF_Mount( pxDisk, ramPARTITION_NUMBER ); ``` 1. scheduler is started after function prvCreateDiskAndExampleFiles() like below ```auto prvCreateDiskAndExampleFiles(); LoggingPrintf("ramdisk creation successful\n"); BSP_LED_On(LED2); xQueue = xQueueCreate( mainQUEUE_LENGTH, sizeof( unsigned long ) ); if( xQueue != NULL ) { xTaskCreate( prvQueueSendTask, "TX", configMINIMAL_STACK_SIZE, NULL, mainQUEUE_SEND_TASK_PRIORITY, NULL ); } /* Start the tasks and timer running. */ vTaskStartScheduler(); ``` ---
**Author:** ![htibosch](https://d3iykfbgfh8zhg.cloudfront.net/user_avatar/forums.freertos.org/htibosch/32/62_2.png) [@htibosch](https://forums.freertos.org/u/htibosch)\ **Post date:** [June 5, 2017, 6:34am UTC](https://forums.freertos.org/t/freertos-fat-ramdisk-creation-on-nucleo-l476rg/6592/11 "2017-06-05T06:34:42Z")
**[heinbali01](https://sourceforge.net/u/heinbali01/)** wrote on [Monday, June 05, 2017](https://sourceforge.net/p/freertos/discussion/382005/thread/59ac4be5/#d4ac): Could you call `prvCreateDiskAndExampleFiles()` after the scheduler has started, from the first task that becomes active, eg. from your `prvQueueSendTask()`? ---
**Author:** ![system](https://d2v6vdsk2p900z.cloudfront.net/original/1X/7fc8fdb729c645aab5b20282bbe34e57cb407be6.jpeg) [@system](https://forums.freertos.org/u/system)\ **Post date:** [June 5, 2017, 7:30am UTC](https://forums.freertos.org/t/freertos-fat-ramdisk-creation-on-nucleo-l476rg/6592/12 "2017-06-05T07:30:35Z")
**[sachingole](https://sourceforge.net/u/sachingole/)** wrote on [Monday, June 05, 2017](https://sourceforge.net/p/freertos/discussion/382005/thread/59ac4be5/#d74c): Hi Hein, I have moved these calls in prvQueueSendTask like below ```auto static void prvQueueSendTask( void *pvParameters ) { TickType_t xNextWakeTime; const unsigned long ulValueToSend = 100UL; /* Remove compiler warning about unused parameter. */ ( void ) pvParameters; /* Initialise xNextWakeTime - this only needs to be done once. */ xNextWakeTime = xTaskGetTickCount(); /* Create the RAM disk used by the FTP and HTTP servers. */ prvCreateDiskAndExampleFiles(); LoggingPrintf("ramdisk creation successful\n"); BSP_LED_On(LED2); ``` Still it didnt help, please see logs below :- ```auto Init boot is done FF_Partition: ffconfigMIN_CLUSTERS_FAT16 = 32 FF_Format: Secs 150 Rsvd 1 Hidden 0 Root 8 Data 141 ``` Seems like this it stuck inside FF\_RAMDiskInit() ---
**Author:** ![system](https://d2v6vdsk2p900z.cloudfront.net/original/1X/7fc8fdb729c645aab5b20282bbe34e57cb407be6.jpeg) [@system](https://forums.freertos.org/u/system)\ **Post date:** [June 5, 2017, 8:30am UTC](https://forums.freertos.org/t/freertos-fat-ramdisk-creation-on-nucleo-l476rg/6592/13 "2017-06-05T08:30:19Z")
**[sachingole](https://sourceforge.net/u/sachingole/)** wrote on [Monday, June 05, 2017](https://sourceforge.net/p/freertos/discussion/382005/thread/59ac4be5/#cf42): Following is function flow, how it reaches to infinite loop :- main.c line no. 180 ```auto pxRAMDisk = FF_RAMDiskInit( mainRAM_DISK_NAME, ucRAMDisk, mainRAM_DISK_SECTORS, mainIO_MANAGER_CACHE_SIZE ); ``` ff\_ramdisk.c line no 183 ```auto xError = prvPartitionAndFormatDisk( pxDisk ); ``` ff\_ramdisk.c line no 368 ```auto xError = FF_Format( pxDisk, ramPARTITION_NUMBER, pdTRUE, pdTRUE ); ``` ff\_format.c line no. 337 ```auto pucSectorBuffer = ( uint8_t * ) ffconfigMALLOC( 512 ); ``` heap\_4.c line no. 151 ```auto void *pvPortMalloc( size_t xWantedSize ) ``` heap\_4.c line no. 280 ```auto ( void ) xTaskResumeAll(); ``` list.c line no. 1698 ```auto ( void ) uxListRemove( &( pxTCB->xEventListItem ) ); ``` list.c line no. 216 ```auto List_t * const pxList = ( List_t * ) pxItemToRemove->pvContainer; ``` line no. 134 ```auto b Infinite_Loop ``` Also I have tried to decrese ram disk from 75KB to 50KB like below :- ```auto define mainRAM_DISK_SECTORS ( ( 50UL * 1024UL ) / mainRAM_DISK_SECTOR_SIZE ) /* 50K bytes. */ ``` Please see function flow, and help me to debug further to find problem. ---
**Author:** ![htibosch](https://d3iykfbgfh8zhg.cloudfront.net/user_avatar/forums.freertos.org/htibosch/32/62_2.png) [@htibosch](https://forums.freertos.org/u/htibosch)\ **Post date:** [June 5, 2017, 9:41am UTC](https://forums.freertos.org/t/freertos-fat-ramdisk-creation-on-nucleo-l476rg/6592/14 "2017-06-05T09:41:42Z")
**[heinbali01](https://sourceforge.net/u/heinbali01/)** wrote on [Monday, June 05, 2017](https://sourceforge.net/p/freertos/discussion/382005/thread/59ac4be5/#84d5): Can you increase the size of the stack for the task that uses +FAT? Now it is only `configMINIMAL_STACK_SIZE`, which won’t be enough. Can you give it 512 words? ---
**Author:** ![system](https://d2v6vdsk2p900z.cloudfront.net/original/1X/7fc8fdb729c645aab5b20282bbe34e57cb407be6.jpeg) [@system](https://forums.freertos.org/u/system)\ **Post date:** [June 5, 2017, 7:14pm UTC](https://forums.freertos.org/t/freertos-fat-ramdisk-creation-on-nucleo-l476rg/6592/15 "2017-06-05T19:14:15Z")
**[sachingole](https://sourceforge.net/u/sachingole/)** wrote on [Monday, June 05, 2017](https://sourceforge.net/p/freertos/discussion/382005/thread/59ac4be5/#aea0): Hi Hein, Thanks a lot for your valueable time and prompt responses. Finally things started working and I am able to create ramdisk with size 50KB. Following are logs :- ```auto Init boot is done FF_Partition: ffconfigMIN_CLUSTERS_FAT16 = 32 FF_Format: Secs 100 Rsvd 1 Hidden 0 Root 8 Data 91 FF_Format: SecCluster 1 DatSec 89 DataClus 89 ulClusterBeginLBA 3 FF_Format: Clearing entire FAT (2 x 1 sectors): FF_Format: Clearing done FF_Format: Clearing root directory at 00000003: 8 sectors FF_RAMDiskInit: FF_Format: FF_Part: no partitions, try as PBR FF_RAMDiskInit: FF_Mount: FF_FS_Add: Table full '/ram' (max = 1) Reading FAT and calculating Free Space pxIOManager->xPartition.ucType = 11 Partition Nr 0 Type 11 (FAT16) VolLabel 'MY NAME F' TotalSectors 100 SecsPerCluster 1 Size 0 MB FreeSize 0 MB ( 100 perc free ) ``` I have 3 task creation code, some either one combination works. Is is it because of memory constraints. Either this task works ```auto xTaskCreate( prvRamDiskTask, "RAMDISKTASK", configMINIMAL_STACK_SIZE, NULL, mainQUEUE_RAMDISK_TASK_PRIORITY, NULL ); ``` Or following 2 task works ```auto xTaskCreate( prvQueueReceiveTask, "Rx", configMINIMAL_STACK_SIZE, NULL, mainQUEUE_RECEIVE_TASK_PRIORITY, NULL ); xTaskCreate( prvQueueSendTask, "TX", configMINIMAL_STACK_SIZE, NULL, mainQUEUE_SEND_TASK_PRIORITY, NULL ); ``` 1. If I have both then it doesnt work. Also I can see following issues in test code. 2. In file CreateAndVerifyExampleFiles.c inside function prvCreateDemoFileUsing\_ff\_fputc `configASSERT( strcmp( pcRAMBuffer, pcFileName ) == 0 );` This fails because pcRAMBuffer = /SUB1/SUB2 and pcFileName = //SUB1/SUB2 1. Looks like ff\_truncate() fails, ```auto pxFile = ff_truncate( pcTestFileName, 1000L ); ff_fclose( pxFile ); ff_stat( pcTestFileName, &xStat ); configASSERT( xStat.st_size == 1000L ); ``` I can see that xStat.st\_size is 0 1. I have observed that prvTest\_ff\_findfirst\_ff\_findnext\_ff\_findclose() inside this funtion it iterate using ff\_findnext( pxFindStruct ) but it returns reaiming 7 but it doesnt return “…” Following is expected to return const char \*pcExpectedRootFiles[] = ```auto { ".", "..", "SUB1", "root001.txt", "root002.txt", "root003.txt", "root004.txt", "root005.txt" }; ```