Controller Pak Filesystem Routines

Managed Controller Pak interface. More...

Functions
int	read_mempak_sector (int controller, int sector, uint8_t *sector_data)
	Read a sector from a Controller Pak. More...
int	write_mempak_sector (int controller, int sector, uint8_t *sector_data)
	Write a sector to a Controller Pak. More...
int	validate_mempak (int controller)
	Return whether a Controller Pak is valid. More...
int	get_mempak_entry (int controller, int entry, entry_structure_t *entry_data)
	Read an entry on a Controller Pak. More...
int	get_mempak_free_space (int controller)
	Return the number of free blocks on a Controller Pak. More...
int	format_mempak (int controller)
	Format a Controller Pak. More...
int	read_mempak_entry_data (int controller, entry_structure_t *entry, uint8_t *data)
	Read the data associated with an entry on a Controller Pak. More...
int	write_mempak_entry_data (int controller, entry_structure_t *entry, uint8_t *data)
	Write associated data to a Controller Pak entry. More...
int	delete_mempak_entry (int controller, entry_structure_t *entry)
	Delete a Controller Pak entry and associated data. More...

Inode values
#define	BLOCK_EMPTY   0x03
	This block is empty.
#define	BLOCK_LAST   0x01
	This is the last block in the note.
#define	BLOCK_VALID_FIRST   0x05
	First valid block that can contain user data.
#define	BLOCK_VALID_LAST   0x7F
	Last valid block that can contain user data.

Detailed Description

Managed Controller Pak interface.

The Controller Pak system is a subsystem of the Controller Subsystem. Before attempting to read from or write to a Controller Pak, be sure you have initialized the controller system with controller_init and verified that you have a mempak in the correct controller using identify_accessory.

To read and write to the Controller Pak in an organized way compatible with official software, first check that the Controller Pak is valid using validate_mempak. If the Controller Pak is invalid, it will need to be formatted using format_mempak. Once the Controller Pak is considered valid, existing notes can be enumerated using get_mempak_entry. To read the data associated with a note, use read_mempak_entry_data. To write a new note to the Controller Pak, use write_mempak_entry_data. Note that there is no append functionality so if a note is being updated, ensure you have deleted the old note first using delete_mempak_entry. Code should be careful to check how many blocks are free before writing using get_mempak_free_space.

Function Documentation

read_mempak_sector()

int read_mempak_sector	(	int	controller,
		int	sector,
		uint8_t *	sector_data
	)

Read a sector from a Controller Pak.

This will read a sector from a Controller Pak. Sectors on Controller Paks are always 256 bytes in size.

Parameters

[in]	controller	The controller (0-3) to read a sector from
[in]	sector	The sector (0-127) to read from
[out]	sector_data	Buffer to place 256 read bytes of data

Return values

0	if reading was successful
-1	if the sector was out of bounds or sector_data was null
-2	if there was an error reading part of a sector

write_mempak_sector()

int write_mempak_sector	(	int	controller,
		int	sector,
		uint8_t *	sector_data
	)

Write a sector to a Controller Pak.

This will write a sector to a Controller Pak. Sectors on Controller Paks are always 256 bytes in size.

Parameters

[in]	controller	The controller (0-3) to write a sector to
[in]	sector	The sector (0-127) to write to
[out]	sector_data	Buffer containing 256 bytes of data to write to sector

Return values

0	if writing was successful
-1	if the sector was out of bounds or sector_data was null
-2	if there was an error writing part of a sector

validate_mempak()

int validate_mempak

(

int

controller

)

Return whether a Controller Pak is valid.

This function will return whether the Controller Pak in a particular controller is formatted and valid.

Parameters

[in]

controller

The controller (0-3) to validate

Return values

0	if the Controller Pak is valid and ready to be used
-2	if the Controller Pak is not present or couldn't be read
-3	if the Controller Pak is bad or unformatted

get_mempak_entry()

int get_mempak_entry	(	int	controller,
		int	entry,
		entry_structure_t *	entry_data
	)

Read an entry on a Controller Pak.

Given an entry index (0-15), return the entry as found on the Controller Pak. If the entry is blank or invalid, the valid flag is cleared.

Parameters

[in]	controller	The controller (0-3) from which the entry should be read
[in]	entry	The entry index (0-15) to read
[out]	entry_data	Structure containing information on the entry

Return values

0	if the entry was read successfully
-1	if the entry is out of bounds or entry_data is null
-2	if the Controller Pak is bad or not present

get_mempak_free_space()

int get_mempak_free_space

(

int

controller

)

Return the number of free blocks on a Controller Pak.

Note that a block is identical in size to a sector. To calculate the number of bytes free, multiply the return of this function by MEMPAK_BLOCK_SIZE.

Parameters

[in]

controller

The controller (0-3) to read the free space from

Returns

The number of blocks free on the memory card or a negative number on failure

format_mempak()

int format_mempak

(

int

controller

)

Format a Controller Pak.

Formats a Controller Pak. Should only be done to wipe a Controller Pak or to initialize the filesystem in case of a blank or corrupt Controler Pak.

Parameters

[in]

controller

The controller (0-3) to format the Controller Pak on

Return values

0	if the Controller Pak was formatted successfully
-2	if the Controller Pak was not present or couldn't be formatted

read_mempak_entry_data()

int read_mempak_entry_data	(	int	controller,
		entry_structure_t *	entry,
		uint8_t *	data
	)

Read the data associated with an entry on a Controller Pak.

Given a valid Controller Pak entry fetched by get_mempak_entry, retrieves the contents of the entry. The calling function must ensure that enough room is available in the passed in buffer for the entire entry. The entry structure itself contains the number of blocks used to store the data which can be multiplied by MEMPAK_BLOCK_SIZE to calculate the size of the buffer needed.

Parameters

[in]	controller	The controller (0-3) to read the entry data from
[in]	entry	The entry structure associated with the data to be read. An entry structure can be fetched based on index using get_mempak_entry
[out]	data	The data associated with an entry

Return values

0	if the entry was successfully read
-1	if input parameters were out of bounds or the entry was corrupted somehow
-2	if the Controller Pak was not present or bad
-3	if the data couldn't be read

write_mempak_entry_data()

int write_mempak_entry_data	(	int	controller,
		entry_structure_t *	entry,
		uint8_t *	data
	)

Write associated data to a Controller Pak entry.

Given a Controller Pak entry structure with a valid region, name and block count, writes the entry and associated data to the Controller Pak. This function will not overwrite any existing user data. To update an existing entry, use delete_mempak_entry followed by write_mempak_entry_data with the same entry structure.

Parameters

[in]	controller	The controller (0-3) to write the entry and data to
[in]	entry	The entry structure containing a region, name and block count
[in]	data	The associated data to write to to the created entry

Return values

0	if the entry was created and written successfully
-1	if the parameters were invalid or the note has no length
-2	if the Controller Pak wasn't present or was bad
-3	if there was an error writing to the Controller Pak
-4	if there wasn't enough space to store the note
-5	if there is no room in the TOC to add a new entry

delete_mempak_entry()

int delete_mempak_entry	(	int	controller,
		entry_structure_t *	entry
	)

Delete a Controller Pak entry and associated data.

Given a valid Controller Pak entry fetched by get_mempak_entry, removes the entry and frees all associated blocks.

Parameters

[in]	controller	The controller (0-3) to delete the note from
[in]	entry	The entry structure that is to be deleted from the Controller Pak

Return values

0	if the entry was deleted successfully
-1	if the entry was invalid
-2	if the Controller Pak was bad or not present