8. Function specifications-1

8.1 Directory management

List

Title Function specifications

Function File system initialization / mounting

Function Name GFS_Init

No 1.1

Form

Sint32 GFS_Init (Sint32 open_max, void * work, GfsDirTbl * dirtbl)

input

open_max	: Maximum number of files to open at the same time (1 to 24)
work	: Work area for the library
dirtbl	: Directory information management structure

output

dirtbl: Directory information management structure (directory information storage area)

Function value

The number of directory information read. Returns a negative error code when an error occurs.

 If NULL is specified for the pointer to the directory information management structure as an argument, the number of directory information held by the CD block file system is returned as a function value.

function

Initializes the file system and mounts the CD-ROM.
Specify the directory management function by specifying dirtbl.

dirtbl	Directory management function to use
Directory management structure	Directory management of this library
NULL	CD block file system directory management

remarks

1. work must be placed on a 4-byte boundary.

2. The INT_ChgMsk function allows SCU level 0-DMA termination interrupts.

3. Initialize the CD block as follows.

(The ECC and retry counts are set to the maximum values, otherwise they remain the defaults.)

・ CD block soft reset	:do not
・ Subcode decoding	:do not
-Mode 2 subheader recognition	:do
・ Form 2 lead retry	:do not
・ CD-ROM data read	: Maximum speed (currently double speed)
・ Standby time	: 180 seconds
・ ECC times	:5 times
·number of retries	: 15 times

List

Title Function specifications

Function Read directory information

Function Name GFS_LoadDir

No 1.2

Form

Sint32 GFS_LoadDir (Sint32 fid, GfsDirTbl * dirtbl)

input

fid	: Directory file identifier
dirtbl	: Directory information management structure

output

dirtbl: Directory information management structure (directory information storage area)

Function value

The number of directories read. Returns a negative error code when an error occurs.

 If NULL is specified for the pointer to the directory information management structure as an argument, the number of directory information held by the CD block file system is returned as a function value.

function

Reads directory information from the specified directory file.
The storage location of directory information changes depending on the specification of dirtbl.

dirtbl	Directory information storage area
Directory management structure	Dirtbl directory information storage area
NULL	File management information area in the CD block

If you specify NULL for dirtbl and GFS_Init does not declare that you want to use the CD block file system, you will get an error. However, it is always possible to pass dirtbl a pointer to a suitable non-null directory information management structure.

List

Title Function specifications

Function Current directory settings

Function Name GFS_SetDir

No 1.3 1.3

Form

Sint 32GFS_SetDir (GfsDirTbl * dirtbl);

input

dirtbl: Directory information management structure

output

none

Function value

Error code.

function

Sets the specified directory information to the current directory.
The directory information used changes depending on the specification of dirtbl.

dirtbl	Directory information to use
Directory management structure	Contents of dirtbl
NULL	File management information in the CD block

When NULL is specified for dirtbl, an error will occur unless GFS_Init declares that the CD block file system will be used. However, it is always possible to pass dirtbl a pointer to a suitable non-null directory information management structure.

List

Title Function specifications

Function Name-to-file identifier conversion

Function Name GFS_NameToId

No 1.4

Form

Sint 32GFS_NameToId (Sint8 * fname)

input

fname: file name

output

none

Function value

File identifier. Negative error code when an error occurs.

function

Returns the file identifier that corresponds to the file name.

List

Title Function specifications

Function Conversion from identifier to filename

Function Name GFS_IdToName

No 1.5

Form

const Sint8 * GFS_IdToName (Sint32 fid)

input

fid: file identifier

output

none

Function value

A pointer to the file name. NULL when an error occurs.

function

Returns a pointer to the file name that corresponds to the file identifier. This pointer points to the conversion table area used by this library.

List

Title Function specifications

Function Get directory information

Function Name GFS_GetDirInfo

No 1.6

Form

Sint32 GFS_GetDirInfo (Sint32 fid, GfsDirId * dirrec)

input

fid: File identifier

output

dirrec: Directory information

Function value

Error code

function

Get directory information from the file identifier.

List

Title Function specifications

Function File system reset

Function Name GFS_Reset

No 1.7 1.7

Form

void GFS_Reset (void)

input

none

output

none

Function value

none

function

Closes all open files and resets the file system.
(Initializes other than directory information.)

remarks

If you are using a stream system, close the stream before executing this function.