Module gba::bios

The GBA’s BIOS provides limited built-in utility functions.

BIOS functions are accessed with an swi instruction to perform a software interrupt. This means that there’s a significant overhead for a BIOS call (tens of cycles) compared to a normal function call (3 cycles, or even none of the function ends up inlined). Despite this higher cost, some bios functions are useful enough to justify the overhead.

Structs

• BitUnpackInfo
  Used to provide info to a call of the BitUnPack function.

Functions

• ArcTan
  0x09: Arc tangent.
• ArcTan2
  0x0A: The “2-argument arctangent” (atan2).
• BitUnPack^⚠
  0x10: Copy data from src to dest while increasing the bit depth of the elements copied.
• HuffUnCompReadNormal^⚠
  0x13: Decompress huffman encoded data.
• IntrWait
  0x04: Waits for a specific interrupt type(s) to happen.
• LZ77UnCompReadNormalWrite8bit^⚠
  0x11: Decompress LZ77 data from src to dest using 8-bit writes.
• LZ77UnCompReadNormalWrite16bit^⚠
  0x12: Decompress LZ77 data from src to dest using 16-bit writes.
• RLUnCompReadNormalWrite8bit^⚠
  0x14: Decompress run-length encoded data (8-bit writes).
• RLUnCompReadNormalWrite16bit^⚠
  0x15: Decompress run-length encoded data (16-bit writes).
• SoftReset
  0x00: Software Reset.
• VBlankIntrWait
  0x05: Builtin shorthand for IntrWait(true, IrqBits::VBLANK)