Hello,
I got:
- STM32F103RC (Cortex-M3), - I2C EEPROM M24128 (16KB, page size 64 bytes), - Flash-FS V4.20.
I modified a FS_SPI_FlashPrg.c from an example to acces an I2C EEPROM. Taking the article http://www.keil.com/support/docs/3482.htm into consideration I described in FS_SPI_FlashDev.h the storage as 8 virtual sectors (blocks) of 2KB each. The EraseSector procedure takes care of writing 0xFF to all 64 Byte long EEPROM pages building a virtual sector.
It works so far that I can format via fformat("S0:") and write a file via f=fopen("S0:\\filename.txt", "w") followed by fputs("Test", f). Both return success, on the dump of the EEPROM the "\filename.txt" string and after some bytes the string "Test" can be seen. At the top of the EEPROM address space masks of the allocation information seem to be present, too, as described in help to EFS.
The problem is: while f=fopen("S0:\\filename.txt", "r") returns success, the following fgets(s, sizeof(s), f) (and fread(...) I tried) returns always NULL. Besides, ffind(...) gets like:
\filename.txt 0, 01-01-1980 12:00:00
Total: 0 Free: 0.
Hello!
It's not FAT but EFS: refer to http://www.keil.com/support/man/docs/rlarm/rlarm_fs_mem_man.htm . I suppose, ffind() ( http://www.keil.com/support/man/docs/rlarm/rlarm_fs_func_maint.htm ) is not able to provide as full file information as for FAT, and some restrictions apply, that are not documented anywhere, OR ffind() is buggy when dealing with EFS. Thus, the fact that ffind() returns file size = 0, means nothing.
I implemented fs_get_time() and fs_get_date() as suggested here http://www.keil.com/support/man/docs/rlarm/rlarm_fs_func_time.htm (based upon a real battery back up'ed RTC in my CPU), but I could not register any calls to the functions when creating a file on EEPROM, though. At the same time, I've got a SD-Card in the system (SPI driven), and the Flash-FS works absolutely properly with it (FAT32), the file time support inclusive.
I have no idea, what happens, and w/o source code I cannot trace it.
This picture could be seen as a suggestion that Keils EFS might potentially use same format for file date/time information as FAT: http://www.keil.com/support/man/docs/rlarm/rlarm_fs_flashfs.htm
Of course, I could be wrong, since I haven't been using any of the Keil-supplied file systems.
Thanks for replies, PPL!
I solved the problem. It was my fault (what else): because of a wrong definition in the code I wrote always two bytes less than needed. Now it works!