melonDS - RetroBIOS

Type	standalone + libretro
Classification	Community forks
Source	https://github.com/libretro/melonDS
Upstream	https://github.com/melonDS-emu/melonDS
Version	Git
Profiled	2026-03-24
Cores	melonds
Systems	nintendo-ds, nintendo-dsi

Technical notes

FreeBIOS fallback for DS mode (NTR); DSi mode requires all native files. Libretro fork based on melonDS ~0.9.x era, validates size only. Upstream adds CRC32 validation on BIOS files (MemConstants.h). DSi SD card emulation controlled by melonds_dsi_sdcard core option.

8 files | 4 required, 4 optional | 8 in repo, 0 missing | 3 with HLE fallback

bios9.bin optional in repo HLE fallback
ARM9 BIOS

• System: nintendo-ds
• Size: 4.0 KB
• CRC32: 2ab23573
• Validation (core): size
• Validation (upstream): size, crc32
• Source: src/NDS.h:196, src/NDS.cpp:467-477, src/frontend/Util_ROM.cpp:99-111
• Platforms: batocera, emudeck, lakka, recalbox, retroarch, retrobat, retrodeck, retropie, rocknix, romm
• FreeBIOS fallback (src/FreeBIOS.h); native needed for Key1 cartridge crypto

bios7.bin optional in repo HLE fallback
ARM7 BIOS

• System: nintendo-ds
• Size: 16.0 KB
• CRC32: 1280f0d5
• Validation (core): size
• Validation (upstream): size, crc32
• Source: src/NDS.h:197, src/NDS.cpp:482-492, src/frontend/Util_ROM.cpp:117-131
• Platforms: batocera, emudeck, lakka, recalbox, retroarch, retrobat, retrodeck, retropie, rocknix, romm
• FreeBIOS fallback (src/FreeBIOS.h); native needed for Key1 init at offset 0x0030

firmware.bin optional in repo HLE fallback
NDS firmware image

• System: nintendo-ds
• Size: min 256.0 KB, max 512.0 KB
• Validation: size
• Source: src/SPI.cpp:192-211, src/frontend/Util_ROM.cpp:174-195
• Platforms: batocera, emudeck, lakka, recalbox, retroarch, retrobat, retrodeck, retropie, rocknix, romm
• Generated 128KB firmware as fallback; native must be 256KB or 512KB for boot

dsi_bios9.bin required in repo
DSi ARM9 BIOS

• System: nintendo-dsi
• Size: 64.0 KB
• CRC32: bae84f6c
• Validation (core): size
• Validation (upstream): size, crc32
• Source: src/DSi.h:33, src/DSi.cpp:587-599, src/frontend/Util_ROM.cpp:145-156
• Platforms: batocera, lakka, retroarch, retrobat, retropie, rocknix

dsi_bios7.bin required in repo
DSi ARM7 BIOS

• System: nintendo-dsi
• Size: 64.0 KB
• CRC32: 4316cc42
• Validation (core): size
• Validation (upstream): size, crc32
• Source: src/DSi.h:34, src/DSi.cpp:604-620, src/frontend/Util_ROM.cpp:158-170
• Platforms: batocera, lakka, retroarch, retrobat, retropie, rocknix
• Contains eMMC key-Y at offset 0x8308 for NAND init

dsi_firmware.bin required in repo
DSi firmware image

• System: nintendo-dsi
• Size: 128.0 KB
• Validation: size
• Source: src/SPI.cpp:197-211, src/frontend/Util_ROM.cpp:201-217
• Platforms: batocera, lakka, retroarch, retrobat, retropie, rocknix

dsi_nand.bin required in repo large_file
DSi NAND dump

• System: nintendo-dsi
• Size: 240.0 MB
• Source: src/frontend/Util_ROM.cpp:224-235, src/DSi_NAND.cpp:58-97
• Platforms: batocera, lakka, retroarch, retropie, rocknix
• Any regional dump works. Nocash footer required (DSi eMMC CID/CPU at EOF-0x40 or 0xFF800). AES keys derived from ARM7i BIOS offset 0x8308.

dsi_sd_card.bin optional in repo
DSi SD card image

• System: nintendo-dsi
• Source: src/frontend/Util_ROM.cpp:237-243, src/libretro/libretro.cpp:837, src/libretro/libretro.cpp:553
• Created if missing; requires melonds_dsi_sdcard core option enabled

Generated on 2026-09-14T09:03:10Z