fformat

#include <rtl.h>

int fformat (
  const char *drive);    /* drive to format */

The fformat function formats the Flash File System storage media on the specified drive. If the drive string is empty (""), fformat uses the default drive specified in the FILE_CONFIG.C configuration file.

The following values are supported for the drive:

All Flash File System drives must be formatted before any files are created on the devices.

• Flash devices must be formatted once when the system is started the first time. They are erased sector by sector as specified in the FS_FLASHDEV.C configuration file.
• RAM devices must be formatted every time when the system starts. They are cleared sector by sector to an erased value (0x00 by default).
• Non-volatile and zero-power RAM devices must be formatted once when the system is started the first time. Since these devices are battery backed up and do not lose their contents when power is removed. They do not require reformatting each time the system starts. Non-volatile and zero-power RAM devices are cleared sector by sector to an erased value (0x00 by default).
• The Memory Card must be formatted before its first use. If a Memory Card has been formatted once, there is no need to format it again. The function formats the Memory Card optimized for 12-bit or 16-bit FAT type. Cluster size and Cluster 2 alignment are optimized for the best Card performance. The Flash File System supports SD and MMC Flash Memory Cards with a maximum capacity of 4 GBytes.

The fformat function is in the RL-FlashFS library. The prototype is defined in rtl.h.

Note

• The fformat function erases all files written to the drive.
• The fformat function closes all opened files on the drive. All existing file handles become invalid. Reading or writing to such files after formatting the drive may produce unpredictable results or file corruption.
• When formatting a Memory Card, you can specify a drive label in the argument drive using the format "M:Drive_Label". The label is written to the drive after the formatting completes. The drive label must have a maximum length of 11 characters and cannot include spaces or special characters.
• The fformat function for Memory Card can accept additional paramters in the argument string:
  • /FAT32 - tells the format function to format the Memory Card using 32-bit FAT file system.
  • /WIPE - tells the format function to clear all the saved data on the Memory Card. All sectors on the Memory Card are overwritten with the default value of 0xFF. Note that this command might take long time to execute on high capacity memory cards.
  The following example will format the Memory Card with 12-bit or 16-bit FAT file system and clear all the data:
  
  

  fformat ("M:SD_CARD /WIPE");
  

#include <rtl.h>

void tst_fformat (void) {

   /* Format a Flash Drive. */
   if (fformat ("F:") != 0) {
      printf ("Flash File System format failed.\n");
   }
   else {
      printf ("Flash File System initialized.\n");
   }

   /* Format an SD Memory Card with Volume Label. */
   if (fformat ("M:SD_CARD") != 0) {
      printf ("SD Memory Card format failed.\n");
   }
   else {
      printf ("SD Memory Card formatted.\n");
   }
}