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Arduous - RetroBIOS
Type libretro
Source https://github.com/libretro/arduous
Version 0.1.0
Profiled 2026-03-18
Cores arduous
Systems arduboy

No BIOS or firmware files required. This core is self-contained.

Arduous is an Arduboy emulator built on simavr (ATmega32U4 AVR simulator) with SSD1306 OLED display emulation, ported to libretro. It is distinct from the Ardens core, which is a separate Arduboy emulator.

No BIOS, bootloader, or system files are required. The core operates as a pure AVR simulator:

  • The game content (.hex Intel HEX format) is parsed at load time via an in-tree ihex reader (arduous.cpp:60-166) and written directly into the simavr flash memory at the address specified in the hex file (arduous.cpp:189). No separate bootloader is loaded.

  • The MCU is hardcoded to atmega32u4 at 16 MHz (arduous.h:70-71). simavr handles CPU initialization internally via avr_make_mcu_by_name().

  • A commented-out loadFirmware() function (arduous.cpp:22-29) suggests ELF firmware loading was considered but never implemented.

  • EEPROM (1024 bytes), system RAM, and VRAM are exposed via the libretro memory interface (RETRO_MEMORY_SAVE_RAM, RETRO_MEMORY_SYSTEM_RAM, RETRO_MEMORY_VIDEO_RAM) but are not loaded from external files.

  • The core never calls RETRO_ENVIRONMENT_GET_SYSTEM_DIRECTORY. The retro_load_game() function only reads the content data buffer passed by the frontend (libretro.cpp:108-110).

  • RETRO_ENVIRONMENT_SET_SUPPORT_NO_GAME is set to false (libretro.cpp:123), meaning a game ROM is always required.

Supported ROM format: Intel HEX (.hex) only. The valid_extensions field lists "hex". A TODO comment mentions .arduboy ZIP support but it is not implemented.

Generated on 2026-03-20T19:12:20Z