AnsweredAssumed Answered

STM322xg Eval board SDIO Problems

Question asked by h.brad on Oct 5, 2011
Latest reply on Oct 18, 2011 by h.brad
Hello all,

I have search through the forums and google for the exact problem I am having to no avail.

The issue I am having is regarding finding the filesystem on the SD card, in particular the check_fs function inside of chk_mounted. From what I understand the function will check for two different signatures. One is the BS_55AA at the end of the 512 byte block and the other is the FAT string somewhere within the block ( depending on the FAT subtype ).

The first signature 55AA is found, but only when I use the f_mkfs ( make filesystem ) in Chan's code. Using windows does not make the signature which I thought was part of any FAT file system. Regardless of which method I use to format the disk I cannot see the FAT string in the block anywhere.

Anyone have/had this issue or have insight as to what might be the problem? I have tried multiple allocation unit sizes when calling makefs.

EDIT: I have tried with both a 256MB and 2GB card. I have actually seen mixed results, but I always see FR_NO_FILESYSTEM.

EDIT2: So I can see when I am reading from the Volume Boot Record the MS DOS string is still at the top where it belongs but aftet that I get a bunch of FF's, enough to overwrite the FAT string.