GBA Memory Domains

Bizhawk-Vanguard exposes the following domains in RTC:

mGBA & VBA-Next

• IWRAM (Rewindable) : Internal (on the same chip as the CPU) work ram. 32kb large on a 32 bit bus. Generally holds the most critical data (ARM code, time sensitive data, etc).

• EWRAM (Rewindable) : External (not on the same chip as the cpu) work ram. 256kb large on a 16 bit bus. Slower than the IWRAM. Holds anything that'd go in WRAM that isn't stored in the IWRAM. Can hold code, but since it's on a 16 bit bus it has to be ARM THUMB code.

• BIOS : The BIOS, don't touch this.

• PALRAM : Palette ram. 1KB Want to swap the colors? Have fun.

• VRAM (Rewindable) : Video ram. 96KB. Holds the actual data drawn to the screen.

• OAM: Object Attribute Memory. 1KB. Contains the actual "object" of things such as sprites (the mode, the size, what palette to use, etc).

• ROM : The ROM file.

• SRAM (Rewindable, unavailable on mGBA) : Saveram. Want to corrupt a save file? Corrupt this.

• Combined WRAM (Rewindable) : IWRAM and EXRAM combined into a single memory domain that contains both.

• System Bus: Theoretically allows access to everything that's mapped as it facillitates the communication between pieces of hardware. In execution, not everything mapped will be visible through this domain. It's a matter of if it was properly exposed or not. Corrupt something here and it'll be reflected in the domains derived from it.

  • 0x00000000 - 0x00003FFF- 16 KB System ROM (executable, but not readable)

  • 0x02000000 - 0x02030000- 256 KB EWRAM (general purpose RAM external to the CPU)

  • 0x03000000 - 0x03007FFF- 32 KB IWRAM (general purpose RAM internal to the CPU)

  • 0x04000000 - 0x040003FF- I/O Registers

  • 0x05000000 - 0x050003FF- 1 KB Colour Palette RAM

  • 0x06000000 - 0x06017FFF- 96 KB VRAM (Video RAM)

  • 0x07000000 - 0x070003FF- 1 KB OAM RAM

  • 0x08000000 - 0x????????- Game Pak ROM (0 to 32 MB)

  • 0x0E000000 - 0x????????- Game Pak RAM

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