mirror of
https://github.com/Abdess/retroarch_system.git
synced 2026-04-13 12:22:33 -05:00
ebc8e4413f
freeintv_ts_overlay (same BIOS as FreeIntv), bnes (NES, no BIOS), clownmdemu (Mega Drive, open-source MCD boot ROM embedded), m2000 (Philips P2000T, all embedded), mesen (NES, FDS + StudyBox BIOS), race (NGP, HLE with disabled BIOS loader), vemulator (VMU, HLE only), gw (Game & Watch, Lua simulator), pd777 (Cassette Vision, no BIOS), play (PS2, full HLE, LoadBIOS commented out) 115 total profiles.
73 lines
2.9 KiB
YAML
73 lines
2.9 KiB
YAML
emulator: VeMUlator
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type: libretro
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source: "https://github.com/libretro/vemulator-libretro"
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cores:
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- vemulator
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systems:
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- sega-vmu
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notes: |
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VeMUlator is a Sega Dreamcast Visual Memory Unit (VMU/VMS) emulator ported
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from Android (Java) to C++ for libretro. It emulates the Sanyo LC8670
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"Potato" CPU, 128 KB flash memory, 48x32 monochrome LCD, piezo buzzer,
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and basic timer subsystems.
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No BIOS files are required. The core uses High Level Emulation (HLE) to
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bypass the VMU firmware entirely:
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- At startup, startCPU() checks the BIOSExists flag (vmu.cpp:195). When
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false (always, in the libretro port), it calls initializeHLE() which
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sets up SFR registers (SP=0x7F, PSW=0x02, IE=0x80, MCR=0x08, P7=0x02,
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OCR=0xA3, BTCR=0x41) and system RAM variables directly (vmu.cpp:206-222).
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- A loadBIOS() function exists in the VMU class (vmu.cpp:82-137) and can
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handle both encrypted (XOR 0x37, 4-byte header stripped) and unencrypted
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BIOS images (first byte must be 0x2A = JMPF opcode). Maximum accepted
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size is 0xF004 (61444) bytes, loaded into 0xF000 (61440) bytes of ROM.
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However, this function is never called by the libretro frontend code.
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retro_load_game() in main.cpp only loads game flash data, with no BIOS
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path resolution or RETRO_ENVIRONMENT_GET_SYSTEM_DIRECTORY call.
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- The README lists "BIOS support" as a planned future feature.
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The .info file declares no firmware entries (firmware_count absent).
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Supported ROM formats: VMS (.vms), DCI (.dci), raw flash dump (.bin).
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The core option "enable_flash_write" allows persistent saves for .bin files.
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files: []
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platform_details:
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hle_implementation:
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source_ref: "vmu.cpp:195-222"
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sfr_init:
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SP: "0x7F"
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PSW: "0x02"
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IE: "0x80"
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MCR: "0x08"
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P7: "0x02"
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OCR: "0xA3"
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BTCR: "0x41"
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ram_init:
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- "0x31 = 0xFF (battery level)"
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- "0x6E = 0xFF"
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- "P3 = 0xFF (no buttons pressed)"
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- "BCD date/time at 0x10-0x16, raw at 0x17-0x1D"
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notes: |
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HLE skips the BIOS boot sequence and jumps directly into the loaded
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game. System clock, date, and button state are initialized in RAM.
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The EXT register is set to 1 to signal HLE mode to the CPU
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(vmu.cpp:198-199). Games that depend on BIOS-initialized state
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beyond what HLE provides may not work correctly.
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unused_bios_loader:
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source_ref: "vmu.cpp:82-137"
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max_file_size: 61444
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rom_load_size: 61440
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encryption: "XOR 0x37 after stripping 4-byte header"
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detection: "first byte 0x2A (JMPF) = unencrypted, otherwise encrypted"
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notes: |
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The loadBIOS() method is fully implemented but unreachable from the
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libretro interface. No system directory query, no BIOS path construction,
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and no call site exists in main.cpp. A future update could wire this up
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to support real VMU firmware boot (file manager, clock, mini-games menu).
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