1.The file “data.txt” is created in the SD card the windows 7. The address is E:\ data.txt
2.The SD card is inserted to the TWRK64F120M.
The example C:\Freescale\Freescale_MQX_4_1_TWRK64F120M\mfs\examples\sdcard\build\iar\mfs_sdcard_twrk64f120m
is used to access the file “data.txt”.
The source code is shown below and the red part is the one to access file data.txt.
filesystem_handle = fopen(filesystem_name, NULL);
error_code = ferror(filesystem_handle);
if (error_code == MFS_NOT_A_DOS_DISK)
{
printf("NOT A DOS DISK! You must format to continue.\n");
}
else if (error_code != MFS_NO_ERROR)
{
printf("Error opening filesystem: %s\n", MFS_Error_text((uint32_t)error_code));
continue;
}
if(filesystem_handle!=NULL)
{printf ("SD card installed to %s\n", filesystem_name);}
if (readonly)
{
printf ("SD card is locked (read only).\n");
}
userfile_ini=fopen("a:\\data.txt", NULL);
The a: is installed successfully.The userfile_ini is always is null.The data.txt can not be openned.
What is the resason?
Remark: The hardware is K64 and the OS is Freescale_MQX_4_1_TWRK64F120M.
The SD card is kingston 4G. File system is FAT32.
Solved! Go to Solution.
Hi Robin,
When you want open file, you should say in which mode you want to open this file.
For example:
fopen("a:data.txt", "w+")
For more details, please check fopen description in MQX MSF User Guide.
Available modes are:"w", "w+", "r", "r+", "r", "a", "a+", "n", "n+".
If you use MQX older than version 4.2 (or KSDK1.2), please try avoid to use append mode ("a", "a+").
There is bug. More details: Re: MFS - file access error
I hope it helps you.
Have a great day,
RadekS
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Hi Robin,
When you want open file, you should say in which mode you want to open this file.
For example:
fopen("a:data.txt", "w+")
For more details, please check fopen description in MQX MSF User Guide.
Available modes are:"w", "w+", "r", "r+", "r", "a", "a+", "n", "n+".
If you use MQX older than version 4.2 (or KSDK1.2), please try avoid to use append mode ("a", "a+").
There is bug. More details: Re: MFS - file access error
I hope it helps you.
Have a great day,
RadekS
-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------