usb hostlite fat32 impplementation

> 1 i am able to create a TXT file but not able to write in it that is when i try to write on this file using LPC2468 host it makes a file of 0 KB when i check it on to PC .

Did you close the file (FatFs: f_close() / HostLite: FILE_Close()), before plugging off the pen drive?
f_open() / FILE_Open creat a file entry of size zero on the directory of the pen drive, if the file is a new one. f_close() / FILE_Close() refresh the file size on the directory.



> F_mount and FAT_init are slightly different function... What ,s the role of disk_initailise function.

Surely, f_mount() initializes just the file system object (persistent context for each drive).
disk_initialize() is called from most of FatFs routines, indirectly. For example,
f_open() -> chk_mounted -> disk_initialize()

I believe it's the author's policy, to confirm if the target media is still mounted or not, at every chance.

Tsuneo

> 1 i am able to create a TXT file but not able to write in it that is when i try to write on this file using LPC2468 host it makes a file of 0 KB when i check it on to PC .

Did you close the file (FatFs: f_close() / HostLite: FILE_Close()), before plugging off the pen drive?
f_open() / FILE_Open creat a file entry of size zero on the directory of the pen drive, if the file is a new one. f_close() / FILE_Close() refresh the file size on the directory.



> F_mount and FAT_init are slightly different function... What ,s the role of disk_initailise function.

Surely, f_mount() initializes just the file system object (persistent context for each drive).
disk_initialize() is called from most of FatFs routines, indirectly. For example,
f_open() -> chk_mounted -> disk_initialize()

I believe it's the author's policy, to confirm if the target media is still mounted or not, at every chance.

Tsuneo

Thanks Sir for your kind support

YES i close that file
my code is like that

void  Main_Write (void)
{
    SWORD32  fdw;
    SWORD32  fdr;
    UWORD32  tot_bytes_written;
    UWORD32  bytes_written;
    UserBuffer = &tmp_buf[0];




        fdw = FILE_Open(FILENAME_W, RDWR);
        if (fdw > 0) {
            tot_bytes_written = 0;

            do {

                bytes_written = FILE_Write(fdw, UserBuffer, 1024);
                tot_bytes_written += bytes_written;
                } while (tot_bytes_written < 1024);
            FILE_Close(fdw);


        }

}

Does the file name includes small letter?
If a file name with small letter is given, the file is not read out, and its size is shown as zero, though the file name appears on Windows.
File name and extension should be all in capital.

Tsuneo

Thanks Sir for your kind support

yes,File name is in capital letter .but sir i solved that problem using following change in main_write function

void  Main_Write (void)
{
    SWORD32  fdw;
    SWORD32  fdr;
    UWORD32  tot_bytes_written;
    UWORD32  bytes_written;
    UWORD8            tmp_buf[64]="ABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMNO";
    UserBuffer = &tmp_buf[0];




        fdw = FILE_Open(FILENAME_W, RDWR);
        if (fdw > 0) {
            tot_bytes_written = 0;

            do {

               // bytes_written = FILE_Write(fdw, UserBuffer, 1024);//earlier
                bytes_written = FILE_Write(fdw, UserBuffer , 64);//now
                tot_bytes_written += bytes_written;
                } while (tot_bytes_written < 1024);
            FILE_Close(fdw);


        }

}

Now i am able to create the file.but a new problem is that when i create file of size upto 0 - 5kb everything is ok.but when I create file of size greater than 8 KB and try to open it on PC.It gives an error

could n,t open L:\MSWRITE.TXT
Make sure a drive in the disk is specified or not

What,s the reason behind it?

Thanks Rohit

Is the buffer passed to FILE_Write() / FILE_Read() placed on the USB RAM (HOST_BASE_ADDR)?

This buffer is directly put into the Transfer Descriptor for DMA by the host controller.
It means the buffer should be placed on the USB RAM.
LPC23xx/24xx families have this restriction on DMA by USB controller.

In the USB host lite example, it manages buffer assignment as follows.

usbhost_lpc2468.c

volatile  HCED        *EDCtrl;        /* Control endpoint descriptor structure                  */
volatile  HCED        *EDBulkIn;      /* BulkIn endpoint descriptor  structure                  */
volatile  HCED        *EDBulkOut;     /* BulkOut endpoint descriptor structure                  */
volatile  HCTD        *TDHead;        /* Head transfer descriptor structure                     */
volatile  HCTD        *TDTail;        /* Tail transfer descriptor structure                     */
volatile  HCCA        *Hcca;          /* Host Controller Communications Area structure          */
          USB_INT16U  *TDBufNonVol;   /* Identical to TDBuffer just to reduce compiler warnings */
volatile  USB_INT08U  *TDBuffer;      /* Current Buffer Pointer of transfer descriptor          */
volatile  USB_INT08U  *FATBuffer;     /* Buffer used by FAT file system                         */
volatile  USB_INT08U  *UserBuffer;    /* Buffer used by application                             */

void  Host_Init (void)
{
    ...
    Hcca       = (volatile  HCCA       *)(HOST_BASE_ADDR+0x000);
    TDHead     = (volatile  HCTD       *)(HOST_BASE_ADDR+0x100);
    TDTail     = (volatile  HCTD       *)(HOST_BASE_ADDR+0x110);
    EDCtrl     = (volatile  HCED       *)(HOST_BASE_ADDR+0x120);
    EDBulkIn   = (volatile  HCED       *)(HOST_BASE_ADDR+0x130);
    EDBulkOut  = (volatile  HCED       *)(HOST_BASE_ADDR+0x140);
    TDBuffer   = (volatile  USB_INT08U *)(HOST_BASE_ADDR+0x150);
    FATBuffer  = (volatile  USB_INT08U *)(HOST_BASE_ADDR+0x1D0);
    UserBuffer = (volatile  USB_INT08U *)(HOST_BASE_ADDR+0x1000);

If the buffer would be placed on the USB RAM, you don't need abuve repeated FILE_Write(). Single FILE_Write() call with whole buffer will do.

Tsuneo

Thanks Sir

No, Sir buffer was not placed on USB RAM.

Thank You so much Sir you solved my problem

you are genuinely a master.

Hello Tsuneo,

Could you tell me why the file name must be capital letters?
How can we make it support small letters?
Thanks a lot.

Ran