bios.h File Reference

Nintendo DS Bios functions. More...

#include "nds/ndstypes.h"

Data Structures
struct	DecompressionStream
	A struct that contains callback function pointers used by the decompression functions. More...
struct	UnpackStruct
	A struct and struct pointer with information about unpacking data. More...
Defines
#define	COPY_MODE_COPY   (0)
	copy a range of memory to another piece of memory
#define	COPY_MODE_FILL   BIT(24)
	fill a piece of memory with a value.
#define	COPY_MODE_HWORD   (0)
	copy in chunks of halfword size.
#define	COPY_MODE_WORD   BIT(26)
	copy in chunks of word size.
Typedefs
typedef u8(*	getByteCallback )(u8 *source)
	Should returns a raw byte of the stream.
typedef int(*	getHeaderCallback )(u8 *source, u16 *dest, u32 arg)
	Should return the header of a compressed stream of bytes.
typedef int(*	getResultCallback )(u8 *source)
	Should verify the result after data got decompressed.
typedef struct DecompressionStream	TDecompressionStream
	A struct that contains callback function pointers used by the decompression functions.
typedef struct UnpackStruct	TUnpackStruct
	A struct and struct pointer with information about unpacking data.
Functions
void	swiChangeSoundBias (int enabled, int delay)
	increments or decrements the sound bias once per delay.
void	swiCopy (const void *source, void *dest, int flags)
	copies or fills some memory.
uint16	swiCRC16 (uint16 crc, void *data, uint32 size)
	calculates a CRC-16 checksum.
void	swiDecodeDelta16 (void *source, void *destination)
	Decodes a stream of bytes based on the difference of the bytes.
void	swiDecodeDelta8 (void *source, void *destination)
	Decodes a stream of bytes based on the difference of the bytes.
int	swiDecompressHuffman (void *source, void *destination, uint32 toGetSize, TDecompressionStream *stream)
	Decompresses Huffman compressed data.
int	swiDecompressLZSSVram (void *source, void *destination, uint32 toGetSize, TDecompressionStream *stream)
	Decompresses LZSS compressed data vram safe.
void	swiDecompressLZSSWram (void *source, void *destination)
	Decompresses LZSS compressed data.
int	swiDecompressRLEVram (void *source, void *destination, uint32 toGetSize, TDecompressionStream *stream)
	Decompresses RLE compressed data vram safe.
void	swiDecompressRLEWram (void *source, void *destination)
	Decompresses RLE compressed data.
void	swiDelay (uint32 duration)
	delays the code.
int	swiDivide (int numerator, int divisor)
	divides 2 numbers.
void	swiDivMod (int numerator, int divisor, int *result, int *remainder)
	divides 2 numbers and stores both the result and the remainder.
void	swiFastCopy (const void *source, void *dest, int flags)
	copies or fills some memory. can only copy in word chunks.
uint16	swiGetPitchTable (int index)
	Returns an entry in the pitch table.
uint16	swiGetSineTable (int index)
	Returns an entry in the sine table.
uint8	swiGetVolumeTable (int index)
	Returns an entry in the volume table.
void	swiHalt (void)
	Halts the CPU untill an interupt occures.
int	swiIsDebugger (void)
	returns 0 if running on a nintendo hardware debugger.
int	swiRemainder (int numerator, int divisor)
	calculate the remainder of an division.
void	swiSetHaltCR (uint8 data)
	Writes a byte of the data to 0x04000301:8.
void	swiSetHaltCR (uint32 data)
	Writes a word of the data to 0x04000300:32.
void	swiSleep (void)
	Halts the CPU and most of the hardware untill an interupt occures.
void	swiSoftReset (void)
	resets the DS.
int	swiSqrt (int value)
	calculates the square root.
void	swiSwitchToGBAMode (void)
	Switches the DS to GBA mode.
void	swiUnpackBits (uint8 *source, uint32 *destination, PUnpackStruct params)
	Unpack data stored in multiple elements in a byte to a larger space.
void	swiWaitForIRQ (void)
	wait for any interrupt.

---

Detailed Description

Nintendo DS Bios functions.

See gbatek for more information.

---

Typedef Documentation

typedef u8(* getByteCallback)(u8 *source)

Should returns a raw byte of the stream.

Parameters:

source

A pointer to the byte.

Returns:

A byte.

typedef int(* getHeaderCallback)(u8 *source, u16 *dest, u32 arg)

Should return the header of a compressed stream of bytes.

The result is a word, with the size of decompressed data in bits 8-31, and bits 0-7 are ignored. This value is also returned by the bios function, unless getResult is non-NULL and returns a negative value. This useally returns the 4 bytes that source points to.

Parameters:

	source	A pointer to the compressed data.
	dest	A pointer to the space where the decompressed data should be copied to.
	arg	A callback value that gets passed to the bios function.

Returns:

The header of the compressed data containing the length of the data and the compression type.

typedef int(* getResultCallback)(u8 *source)

Should verify the result after data got decompressed.

getResult is used to provide a result for the bios function, given the source pointer after all data has been read (or if getSize < 0). Its value is only returned if negative, otherwise the typical result is used, so it is likely some sort of error-checking procedure.

Parameters:

source

The current source address.

Returns:

0 if it went right, or a negative number if something went wrong. value will be returned from bios function if value is negative.

---

Function Documentation

void swiChangeSoundBias	(	int	enabled,
		int	delay
	)

increments or decrements the sound bias once per delay.

Parameters:

	enabled	0 to decrement it until it reaches 0x000, 1 to increment it until it reaches 0x200.
	delay	Is in the same units of time as swiDelay.

Note:

ARM7 exclusive.

void swiCopy	(	const void *	source,
		void *	dest,
		int	flags
	)

copies or fills some memory.

Parameters:

	source	pointer to transfer source or pointer to value to fill the memory with.
	dest	pointer to transfer destination.
	flags	bits(0-20): size of data to copy/fill in words, or'd with the copy mode size (word or halfword) and type (copy or fill).

Examples:

Graphics/Sprites/allocation_test/source/main.c.

uint16 swiCRC16	(	uint16	crc,
		void *	data,
		uint32	size
	)

calculates a CRC-16 checksum.

Parameters:

	crc	starting CRC-16 value.
	data	pointer to data (processed nibble by nibble)
	size	size in bytes.

Returns:

the CRC-16 after the data has been processed.

void swiDecodeDelta16	(	void *	source,
		void *	destination
	)

Decodes a stream of bytes based on the difference of the bytes.

Parameters:

	source	Pointer to a header word, followed by encoded data. word(31..8) = size of data (in bytes). word(7..0) = ignored.
	destination	Destination address.

Note:

Writes data a halfword at a time.

ARM9 exclusive.

void swiDecodeDelta8	(	void *	source,
		void *	destination
	)

Decodes a stream of bytes based on the difference of the bytes.

Parameters:

	source	Pointer to a header word, followed by encoded data. word(31..8) = size of data (in bytes). word(7..0) = ignored.
	destination	Destination address.

Note:

Writes data a byte at a time.

ARM9 exclusive.

int swiDecompressHuffman	(	void *	source,
		void *	destination,
		uint32	toGetSize,
		TDecompressionStream *	stream
	)

Decompresses Huffman compressed data.

Parameters:

	source	Pointer to source data (always goes through the function pointers, so could just be an offset).
	destination	Pointer to destination.
	toGetSize	Callback value that is passed to getHeaderCallback function pointer.
	stream	Pointer to struct with callback function pointers.

Returns:

The length of the decompressed data, or a signed errorcode from the Open/Close functions.

See also:

decompress.h

int swiDecompressLZSSVram	(	void *	source,
		void *	destination,
		uint32	toGetSize,
		TDecompressionStream *	stream
	)

Decompresses LZSS compressed data vram safe.

Parameters:

	source	Pointer to source data (always goes through the function pointers, so could just be an offset).
	destination	Pointer to destination.
	toGetSize	Callback value that is passed to getHeaderCallback function pointer.
	stream	Pointer to struct with callback function pointers.

Returns:

The length of the decompressed data, or a signed errorcode from the Open/Close functions.

Note:

Writes data a halfword at a time.

See also:

decompress.h

void swiDecompressLZSSWram	(	void *	source,
		void *	destination
	)

Decompresses LZSS compressed data.

Parameters:

	source	pointer to a header word, followed by compressed data. bit 0-7 of header is ignored. bit 8-31 of header is size of uncompressed data in bytes.
	destination	destination address.

Note:

Writes data a byte at a time.

See also:

decompress.h

int swiDecompressRLEVram	(	void *	source,
		void *	destination,
		uint32	toGetSize,
		TDecompressionStream *	stream
	)

Decompresses RLE compressed data vram safe.

compressed data format: bit(7): 0= uncompressed, 1= compressed. bit(0-6) when uncompressed: run length - 1, followed by run_length bytes of true data. bit(0-6) when compressed: run length - 3, followed by one byte of true data, to be repeated.

Parameters:

	source	Pointer to source data (always goes through the function pointers, so could just be an offset).
	destination	Pointer to destination.
	toGetSize	Callback value that is passed to getHeaderCallback function pointer.
	stream	Pointer to struct with callback function pointers.

Returns:

The length of the decompressed data, or a signed errorcode from the Open/Close functions.

Note:

Writes data a halfword at a time.

See also:

decompress.h

void swiDecompressRLEWram	(	void *	source,
		void *	destination
	)

Decompresses RLE compressed data.

compressed data format: bit(7): 0= uncompressed, 1= compressed. bit(0-6) when uncompressed: run length - 1, followed by run_length bytes of true data. bit(0-6) when compressed: run length - 3, followed by one byte of true data, to be repeated.

Parameters:

	source	pointer to a header word, followed by compressed data. bit 0-7 of header is ignored. bit 8-31 of header is size of uncompressed data in bytes.
	destination	destination address.

Note:

Writes data a byte at a time.

See also:

decompress.h

void swiDelay

(

uint32

duration

)

delays the code.

Delays for for a period X + Y*duration where X is the swi overhead and Y is a cycle of

     loop:
       sub r0, #1
       bgt loop

of thumb fetches in BIOS memory

Parameters:

duration

length of delay

Note:

Duration should be 1 or more, a duration of 0 is a huge delay.

int swiDivide	(	int	numerator,
		int	divisor
	)

divides 2 numbers.

Parameters:

	numerator	signed integer to divide
	divisor	signed integer to divide by

Returns:

numerator / divisor

void swiDivMod	(	int	numerator,
		int	divisor,
		int *	result,
		int *	remainder
	)

divides 2 numbers and stores both the result and the remainder.

Parameters:

	numerator	signed integer to divide
	divisor	signed integer to divide by
	result	pointer to integer set to numerator / divisor
	remainder	pointer to integer set to numerator % divisor

void swiFastCopy	(	const void *	source,
		void *	dest,
		int	flags
	)

copies or fills some memory. can only copy in word chunks.

Parameters:

	source	pointer to transfer source or pointer to value to fill the memory with.
	dest	pointer to transfer destination.
	flags	bits(0-20): size of data to copy/fill in words, or'd with the type (copy or fill).

Note:

Transfers more quickly than swiCopy, but has higher interrupt latency.

uint16 swiGetPitchTable

(

int

index

)

Returns an entry in the pitch table.

Parameters:

index

The index of the pitch table (0-767).

Returns:

The entry.

Note:

ARM7 exclusive.

uint16 swiGetSineTable

(

int

index

)

Returns an entry in the sine table.

Parameters:

index

The index of the sine table (0-63).

Returns:

The entry.

Note:

ARM7 exclusive.

uint8 swiGetVolumeTable

(

int

index

)

Returns an entry in the volume table.

Parameters:

index

The index of the volume table (0-723).

Returns:

The entry.

Note:

ARM7 exclusive.

void swiHalt

(

void

)

Halts the CPU untill an interupt occures.

Note:

ARM7 exclusive.

int swiIsDebugger

(

void

)

returns 0 if running on a nintendo hardware debugger.

Returns:

0 if running on a debugger (8 MB of ram instead of 4 MB), else some other number.

int swiRemainder	(	int	numerator,
		int	divisor
	)

calculate the remainder of an division.

Parameters:

	numerator	signed integer to divide
	divisor	signed integer to divide by

Returns:

numerator % divisor

void swiSetHaltCR

(

uint8

data

)

Writes a byte of the data to 0x04000301:8.

Parameters:

data

The byte to write.

Note:

ARM7 exclusive.

void swiSetHaltCR

(

uint32

data

)

Writes a word of the data to 0x04000300:32.

Parameters:

data

the word to write.

Note:

This is on the ARM9, but works differently then the ARM7 function!

void swiSleep

(

void

)

Halts the CPU and most of the hardware untill an interupt occures.

Note:

ARM7 exclusive.

int swiSqrt

(

int

value

)

calculates the square root.

Parameters:

value

the value to calculate.

Returns:

the square root of the value as an integer.

Note:

use fixed point math if you want more accuracy.

void swiSwitchToGBAMode

(

void

)

Switches the DS to GBA mode.

Note:

ARM7 exclusive.

void swiUnpackBits	(	uint8 *	source,
		uint32 *	destination,
		PUnpackStruct	params
	)

Unpack data stored in multiple elements in a byte to a larger space.

i.e. 8 elements per byte (i.e. b/w font), into 1 element per byte.

Parameters:

	source	Source address.
	destination	destination address (word aligned).
	params	pointer to an UnpackStruct.

void swiWaitForIRQ

(

void

)

wait for any interrupt.

Note:

ARM9 exclusive.