net/fs.h File Reference


Detailed Description

Primary File System.

Author:
Modtronix Engineering
Compiler:
MPLAB C18 v2.10 or higher
HITECH PICC-18 V8.35PL3 or higher

Description

This module only contains defines for functions that are mapped to the Primary File System. There can only be one Primary File System. For example, to make the FSEE module the primary File System, place the following line in the "projdefs.h" file:
 #define FSEE_IS_PRIMARY_FS


Data Structures

struct  _FILE_INFO

Defines

#define FILE   BYTE
#define FILE_INVALID
#define FILE_POS
#define FILEFLAG_EOF   0x40
#define FILEFLAG_ERROR   0x20
#define FILEFLAG_READING   0x02
#define FILEFLAG_RES   0x80
#define FILEFLAG_USED   0x01
#define FILEFLAG_WRITING   0x04
#define fileHasError(fhandle)
#define fileIsEOF(fhandle)
#define fileIsOK(fhandle)
#define fileIsValidHandle(fhandle)
#define FSYS_NOT_AVAILABLE
#define FSYS_POS
#define FSYSFLAG_AVAILABLE   0x01
#define fsysIsInUse()

Typedefs

typedef _FILE_INFO FSEE_FILE_INFO

Functions

void fileClose (FILE fhandle)
void fileFlush (FILE fhandle)
BYTE fileGetByte (FILE fhandle)
FSEE_POS fileGetFAT (BYTE *name)
FILE_POS fileGetPos (FILE fhandle)
FILE fileOpen (BYTE *name, BYTE mode)
FILE fileOpenFAT (FSYS_POS fatPos)
FILE fileOpenImage ()
BOOL filePutByte (FILE fhandle, BYTE b)
void fileRelease (FILE fhandle)
void fileSetPos (FILE fhandle, FILE_POS put)
BOOL fsysFormat (void)
BOOL fsysInit (void)


Define Documentation

#define FILE   BYTE

FILE handle. Each open files is assigned a file handle.

Examples:
ex_file_read.c.

#define FILE_INVALID

When FILE Handle has this value, it indicates an invalid file

Examples:
ex_file_read.c.

#define FILE_POS

FILE position pointer. A variable that can be used to give the offset anywhere in a file.

#define FILEFLAG_EOF   0x40

FILE flag. When set, indicates that then end of file has been reached.

#define FILEFLAG_ERROR   0x20

FILE flag. When set, indicates that an error has occured with this file.

#define FILEFLAG_READING   0x02

FILE flag. Indicates that we are currently reading from this file. For I2C devices, this means that the memory chip is in sequencial read mode and has control of the I2C bus! Before the bus can be used by any other node, it has to be released!

#define FILEFLAG_RES   0x80

FILE flag. Reserve (don't use) signed bit, is implemented differently by different compilers

#define FILEFLAG_USED   0x01

FILE flag. When set, indicates that this file is being used.

#define FILEFLAG_WRITING   0x04

FILE flag. Indicates that we are currently writing to this file. For I2C devices, this means that the memory chip is in sequencial write mode and has control of the I2C bus! Before the bus can be used by any other node, it has to be released!

#define fileHasError ( fhandle   ) 

Tests if the last operation on the given file generated an error.

Returns:
TRUE if last operation on file generated and error.
FALSE if otherwise.
Examples:
ex_file_read.c.

#define fileIsEOF ( fhandle   ) 

Tests if the given file has reached it's EOF. This will happen:

Returns:
TRUE if given file has reached end of file.
FALSE if otherwise.
Examples:
ex_file_read.c.

#define fileIsOK ( fhandle   ) 

Tests if the last operation on the given file completed without an EOF or Error. If this function returns false, use the fileIsEOF() and fileIsOK() functions to determine exact condition.

Returns:
TRUE if last operation on file was successfull
FALSE if the last operation on the file generated and EOF or Error

#define fileIsValidHandle ( fhandle   ) 

Tests if the given FILE handle is a valid handle. A valid FILE handle is a value that could be assigned to an open file. Possible invalid FILE handles are FILE_INVALID and FSYS_NOT_AVAILABLE

Returns:
TRUE if given FILE handle value could be a valid FILE handle
FALSE if it is not a possible FILE handle value

#define FSYS_NOT_AVAILABLE

When FILE Handle has this value, it indicates that the File System is not available

Examples:
ex_file_read.c.

#define FSYS_POS

File System position pointer. A variable that can be used to give the offset anywhere in the File System.

#define FSYSFLAG_AVAILABLE   0x01

File System flag. When set, indicates that the File System is available.

 
#define fsysIsInUse (  ) 

Indicates if the File System is currently in use.

Returns:
TRUE if it is currently being used FALSE if not


Typedef Documentation

typedef struct _FILE_INFO FSEE_FILE_INFO

FILE structure. Each file that is opened is assigned a FILE structure by the File System.


Function Documentation

void fileClose ( FILE  fhandle  ) 

Closes the given file. Seeing that the File System can only have a limited amount of files open at any time (defined by FSEE_MAX_FILES), it is very important to call this function after finished with a file!

Parameters:
fhandle FILE handle of the file to be released
Examples:
ex_file_read.c.

void fileFlush ( FILE  fhandle  ) 

Finishes writing any data that has not yet been written to the File System. When writing data to a file via the filePutByte() function, it is not always written straight to the File System Media, but some times to an intermediate buffer. This function will write all pending data from the buffer to the File System Media.

BYTE fileGetByte ( FILE  fhandle  ) 

Reads the next byte from current open file.

Caller must call fileIsEOF() to check for end of file condition before calling this function to make sure the file has not reached it's end. If the fileIsEOF() returns true, then this function will have no affect!

Caller must call fileHasError() function after calling this function to ensure byte was read without error!

This function will place the EEPROM in sequencial read mode and take control of the I2C bus! To allow other devices to use the I2C bus while the file is open, call fileRelease() when finished reading some data. When calling fileRead() after calling fileRelease(), the EEPROM will automatically be placed in sequencial read mode again and take control of the bus.

To read multiple bytes, see ex_file_read.c example file.

Pre-Condition:
fileOpen() != FILE_INVALID and
fileGetByteBegin() == TRUE
Parameters:
fhandle FILE handle of the file to be released
Returns:
Data byte from current address.
Examples:
ex_file_read.c.

FSEE_POS fileGetFAT ( BYTE name  ) 

Gets the address in the File System of the requested file's FAT entry. This address can be used as a fast way to open files in the future with the fileOpenFAT() function.

!!! IMPORTANT !!! The File System FAT entry address obtained with the fileGetFAT() function will only be valid as long as no modifications are made to the File System! If after obtaining a address with the fileGetFAT() function the File System is modified, this value might not be valid any more!

FILE_POS fileGetPos ( FILE  fhandle  ) 

Get the current file pointer for the given file. This is the offset in the given file that the next read or write will be performed on. This value can be used as a parameter to the fileSetPos() function at a later stage to restore the current file position. This is NOT the file address in the file system.

FILE fileOpen ( BYTE name,
BYTE  mode 
)

Opens the given file for reading or writing, and returns a handle to the file. The file pointer (where next read or write will occur) will be positioned at the beginning of the file. To modify the file pointer use the fileSetPos() function.

Parameters:
name NULL terminate file name.
mode Currently not used. All files are opened with read and write permission. When writing to a file, no data can be appended to it!
Returns:
- A FILE Handle (value 0 - 127) if the file is found
  • FILE_INVALID if file could not be opened
  • FSYS_NOT_AVAILABLE if the File System is not available
Examples:
ex_file_read.c.

FILE fileOpenFAT ( FSYS_POS  fatPos  ) 

Opens the given file for reading or writing, and returns a handle to the file. The file pointer (where next read or write will occur) will be positioned at the beginning of the file. To modify the file pointer use the fileSetPos() function.

!!! IMPORTANT !!! The File System FAT entry address obtained with the fileGetFAT() function will only be valid as long as no modifications are made to the File System! If after obtaining a address with the fileGetFAT() function the File System is modified, this value might not be valid any more!

Parameters:
fatPos The requested File's FAT address in the File System. This value has to be obtained from a fileGetFAT() function.
Returns:
- A FILE Handle (value 0 - 127) if the file is found
  • FILE_INVALID if file could not be opened
  • FSYS_NOT_AVAILABLE if the File System is not available

FILE fileOpenImage (  ) 

Prepares the File System to receive a new Image via following calls to filePutByte()! The given image must contain the FAT and all file data.

!!! IMPORTANT !!! This function will overwrite the entire File System! All data will be lost!

Returns:
TRUE if successful
FALSE if otherwise

BOOL filePutByte ( FILE  fhandle,
BYTE  b 
)

Writes a byte to the given file.

Caller must call fileIsEOF() to check for end of file condition before calling this function to make sure the file has not reached it's end. If the fileIsEOF() returns true, then this function will have no affect!

Writes a byte to the current output. Actual write may not get started until internal write page is full. To ensure that previously data gets written, caller must call fileFlush() after last call to filePutByte().

Pre-Condition:
fileOpen() was successfully called.
Parameters:
fhandle FILE handle to the file to be activated
b byte to be written
Returns:
TRUE if successful
FALSE if otherwise

void fileRelease ( FILE  fhandle  ) 

Releases any resources that the given open file might be reserving. On certian File Systems, like ones that use EEPROMs on a shared I2C bus for example, the File System will take control of the bus once a file is opened. To release the bus so it can be used by other modules, the fileRelease() function has to be called. At a later stage, when the file has to be used again, the fileActive() function has to be called.

This function should be called when a file has been opened, and we don't want to close it now, but still want to use it at a later stage. In this case, we can call fileRelease() and suspend operation to the system to perform other tasks. When at a later stage we want to use this file again, fileActivate() will automatically be called by the file read and write functions.

Pre-Condition:
fileOpen() was successfully called.
Parameters:
fhandle FILE handle of the file to be released

void fileSetPos ( FILE  fhandle,
FILE_POS  put 
)

Set the current file pointer for the given file. This is the offset in the given file that the next read or write will be performed on.

BOOL fsysFormat ( void   ) 

Deletes all files present on the File System

Returns:
TRUE if successful
FALSE otherwise

BOOL fsysInit ( void   ) 

Initializes the Modtronix File System

Returns:
TRUE, if File System Storage access is initialized and File System is is ready to be used
FALSE otherwise


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