TODO.md

• Graphics
  • Backdrop and forced blank
  • Tile modes
    • Scrolling
    • Priorities
    • Transparency color
    • Tile flipping
    • 32 and 256 color palettes
  • Bitmap modes
    • Page flipping
    • Affine transformation (e.g. Advance Wars intro, Ecks vs. Sever)
    • Priorities (e.g. Iridion II intro)
  • Tiled and affine backgrounds
    • Layer toggle delay
  • Regular and affine sprites
    • Tile indexes past 1023 wrap around to 0 allowing tile 0 to be placed at sprite origin (e.g. Advance Wars 2 versus rules screen)
    • Tile indexes for 2D mapped tiles incremented past end of row wrap around to the same row
    • Affine matrix of all zeros produces rectangle of uniform color using origin pixel (e.g. Kurukuru Kururin intro and pause menu)
    • Transparent sprites can update sprite priorities (e.g. Golden Sun carpet)
    • OAM update delay
  • Graphic effects
    • Blending
    • Mosaic
    • Windowing
      • Basic windows
      • Object window
      • Bad values for window coordinates
  • Shaders
    • LCD color correction
• Sound
  • Digital sound channels
  • Programmable sound generators
    • Square 1
    • Square 2
    • Wave
    • Noise
  • Resampling
    • Sample rates less than 48,000 Hz
    • Sample rates greater than 48,000 Hz (e.g. Golden Sun 2, Konami Krazy Racers)
    • Mixing dissimilar sample rates (e.g. Medabots AX, Mobile Suit Gundam Seed)
    • Interpolation
      • Cosine interpolation
      • Cubic interpolation
      • Sinc interpolation
      • Lanczos interpolation
  • Sound bias register
• Timings
  • Scheduler optimisation
  • Memory region timings
  • Wait count register
  • Instruction timings
  • Timers are updated during a DMA transfer
  • Higher priority DMAs can be initiated during a DMA transfer
  • DMAs delayed by 2 cycles
  • IRQs delayed by 7 cycles (e.g. Hamtaro - Ham-Ham Heartbreak, Mega Man & Bass)
  • Cartridge prefetch
• Memory
  • BIOS read lockout
  • I/O registers
  • Mirroring
  • Open bus
    • ARM
    • Thumb (e.g. The Legend of Zelda: The Minish Cap, Mario & Luigi: Superstar Saga)
      • Work RAM 256K, Palette RAM, VRAM and GamePak ROM
      • BIOS ROM and OAM
      • Work RAM 32K
      • I/O and GamePak SRAM
    • DMA (e.g. Hello Kitty Collection, Sonic Pinball Party)
• Save memory
  • SRAM, Flash and EEPROM support
  • Persist save game to disk
    • On exit or ROM load
    • Automatically with mmap
  • Save type detection via string search
  • Save type overrides
    • Hardcoded
    • Loaded from text file
    • Loaded from save type database
  • Save states
• Timers
• DMA
• Key input
• Interrupt requests
  • VBlank, VCount and HBlank
  • Timers
  • DMA transfers
  • Key input
• CPU
  • Instruction decode via lookup table
  • ALU and shifter
  • Pipeline
  • Conditional execution
  • Software and hardware interrupts
  • ldrt/strt user bank registers
  • ARM edge cases
    • ldr/str aligns addresses and does rotated reads
    • ldm/stm aligns addresses and does not rotate reads, updated base retains misalignment
    • CPSR bit 4 (M[4]) always reads as 1 (e.g. Banjo-Kazooie: Grunty's Revenge)
    • Invalid CPSR mode
    • Reading SPSR in modes where SPSR does not exist results in CPSR
    • Changing Thumb bit via msr
    • ldm^/stm^ user bank registers with writeback loads base from non-user bank but stores updated base into user bank
    • tstp/teqp/cmpp/cmnp (ARMv2 mode change) restores SPSR only, mode is unchanged
    • ldm/stm with empty register list loads/stores PC and increments/decrements base Rn by 0x40
    • ldm with base Rn in register list ignores writeback
    • stm with base Rn first in register list stores unmodified base
    • bx aligns ARM addresses to word, Thumb addresses to halfword
    • Undefined instructions
  • Thumb edge cases
    • Using the second half of a bl instruction pair on its own (e.g. Golden Sun)
    • add/cmp/mov high registers (with both registers low)
    • blx (not on ARMv4T)
    • bx (non-zero should be zero bits)
    • add/sub sp (non-zero should be zero bits)
    • push/pop (non-zero should be zero bits)
• GPIO peripherals
  • Real time clock (e.g. Pokémon Emerald)
  • Gyroscope (e.g. WarioWare: Twisted!)
  • Accelerometer (e.g. Yoshi Topsy-Turvy)
  • Solar sensor (e.g. Boktai)
  • Rumble (e.g. Drill Dozer)
  • e-Reader
• Communication
  • Link cable
  • Wireless adapter
• Debugging
  • Registers
  • Disassembly
    • Scrollable window
  • Stepping
    • Reset
    • Single step
    • Step n cycles
    • Step 1 frame
  • Breakpoints
  • Memory viewer
    • Jump to region
  • Palette viewer
  • Background viewer
  • Sprite viewer
  • GDB remote debug protocol
• User interface
  • Drag and drop ROM file
  • Screen scale
  • Remap controls
  • Rotate screen 90° (e.g. Dr. Mario + Puzzle League)