libtonc: BIOS functions

Tonclib

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BIOS functions
[Bios Calls]


Reset functions

void SoftReset (void)
void RegisterRamReset (u32 flags)

Halt functions

void Halt (void)
void Stop (void)
void IntrWait (u32 flagClear, u32 irq)
void VBlankIntrWait (void)
 Wait for the next VBlank (swi 05h).

Math functions

s32 Div (s32 num, s32 den)
 Basic integer division (swi 06h).
s32 DivArm (s32 den, s32 num)
 Basic integer division, but with switched arguments (swi 07h).
u32 Sqrt (u32 num)
 Integer Square root (swi 08h).
s16 ArcTan (s16 dydx)
 Arctangent of dydx (swi 08h).
s16 ArcTan2 (s16 x, s16 y)
 Arctangent of a coordinate pair (swi 09h).

Memory copiers/fillers

void CpuSet (const void *src, void *dst, u32 mode)
 Transfer via CPU in (half)word chunks.
void CpuFastSet (const void *src, void *dst, u32 mode)
 A fast transfer via CPU in 32 byte chunks.

Rot/scale functions

void ObjAffineSet (const ObjAffineSource *src, void *dst, s32 num, s32 offset)
 Sets up a simple scale-then-rotate affine transformation (swi 0Eh).
void BgAffineSet (const BgAffineSource *src, BgAffineDest *dst, s32 num)
 Sets up a simple scale-then-rotate affine transformation (swi 0Eh).

Decompression (see GBATek for format details)

void BitUnPack (const void *src, void *dst, const BUP *bup)
void LZ77UnCompWram (const void *src, void *dst)
void LZ77UnCompVram (const void *src, void *dst)
void HuffUnComp (const void *src, void *dst)
void RLUnCompWram (const void *src, void *dst)
void RLUnCompVram (const void *src, void *dst)
void Diff8bitUnFilterWram (const void *src, void *dst)
void Diff8bitUnFilterVram (const void *src, void *dst)
void Diff16bitUnFilter (const void *src, void *dst)

Sound Functions

void SoundBias (u32 bias)
void SoundDriverInit (void *src)
void SoundDriverMode (u32 mode)
void SoundDriverMain (void)
void SoundDriverVSync (void)
void SoundChannelClear (void)
u32 MidiKey2Freq (void *wa, u8 mk, u8 fp)
void SoundDriverVSyncOff (void)
void SoundDriverVSyncOn (void)

Multiboot handshake

int MultiBoot (MultiBootParam *mb, u32 mode)

Functions

u32 BiosCheckSum (void)

Function Documentation

s16 ArcTan ( s16  dydx  ) 

Arctangent of dydx (swi 08h).

Parameters:
dydx Slope to get the arctangent of.
Returns:
Arctangent of dydx in the range <-4000h, 4000h>, corresponding to <-½π, ½π> .
Note:
Said to be inaccurate near the range's limits.

s16 ArcTan2 ( s16  x,
s16  y 
)

Arctangent of a coordinate pair (swi 09h).

This is the full-circle arctan, with an angle range of [0,FFFFh].

void BgAffineSet ( const BgAffineSource *  src,
BgAffineDest *  dst,
s32  num 
)

Sets up a simple scale-then-rotate affine transformation (swi 0Eh).

Uses a single ObjAffineSource struct to set up an array of affine matrices (either BG or Object) with a certain transformation. The matrix created is

sx·cos(α) -sx·sin(α)
sy·sin(α) sy·cos(α)

Parameters:
src Array with scale and angle information.
dst Array of affine matrices, starting at a pa element.
num Number of matrices to set.
offset Offset between affine elements. Use 2 for BG and 8 for object matrices.
Note:
Each element in src needs to be word aligned, which devkitPro doesn't do anymore by itself.

void CpuFastSet ( const void *  src,
void *  dst,
u32  mode 
)

A fast transfer via CPU in 32 byte chunks.

This uses ARM's ldmia/stmia instructions to copy 8 words at a time, making it rival DMA transfers in speed. With bit 26 set it will keep the source address constant, effectively performing fills instead of copies.

Parameters:
src Source address.
dst Destination address.
mode Number of words to transfer, and mode bits.
Note:
Both source and destination must be word aligned; the number of copies must be a multiple of 8.

In fill-mode (bit 26), the source is still an address, not a value.

memcpy32/16 and memset32/16 basically do the same things, but safer. Use those instead.

void CpuSet ( const void *  src,
void *  dst,
u32  mode 
)

Transfer via CPU in (half)word chunks.

The default mode is 16bit copies. With bit 24 set, it copies words; with bit 26 set it will keep the source address constant, effectively performing fills instead of copies.

Parameters:
src Source address.
dst Destination address.
mode Number of transfers, and mode bits.
Note:
This basically does a straightforward loop-copy, and is not particularly fast.

In fill-mode (bit 26), the source is still an address, not a value.

s32 Div ( s32  num,
s32  den 
)

Basic integer division (swi 06h).

Parameters:
num Numerator.
den Denominator.
Returns:
num / den
Note:
div/0 results in an infinite loop. Try DivSafe instead

s32 DivArm ( s32  den,
s32  num 
)

Basic integer division, but with switched arguments (swi 07h).

Parameters:
num Numerator.
den Denominator.
Returns:
num / den
Note:
div/0 results in an infinite loop.

void ObjAffineSet ( const ObjAffineSource *  src,
void *  dst,
s32  num,
s32  offset 
)

Sets up a simple scale-then-rotate affine transformation (swi 0Eh).

Uses a single ObjAffineSource struct to set up an array of affine matrices (either BG or Object) with a certain transformation. The matrix created is

sx·cos(α) -sx·sin(α)
sy·sin(α) sy·cos(α)

Parameters:
src Array with scale and angle information.
dst Array of affine matrices, starting at a pa element.
num Number of matrices to set.
offset Offset between affine elements. Use 2 for BG and 8 for object matrices.
Note:
Each element in src needs to be word aligned, which devkitPro doesn't do anymore by itself.

void VBlankIntrWait ( void   ) 

Wait for the next VBlank (swi 05h).

Note:
Requires clearing of REG_IFBIOS bit 0 at the interrupt tonc's master interrupt handler does this for you.

Generated on Mon Aug 25 17:03:57 2008 for libtonc by  doxygen 1.5.3

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