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D.Smile - RetroBIOS
Type standalone
Classification Other
Source https://github.com/derik-dot-digital/D.Smile
Version 0.4.4
Profiled 2026-08-11
Cores dsmile
Systems vtech-vsmile
Technical notes

V.Smile emulator for Android, package com.dsmile.emulator, built on an SPG200 (unSP) core of its own. Frontends launch the exported EmuActivity either with ACTION_VIEW and a content or file Uri, or with the LAUNCH_GAME action and a rom, ROM, path or uri string extra carrying a path; ES-DE uses the first form. ref: AndroidManifest.xml:34-51, EmuActivity.kt:123-145, docs/iisu-integration.md:42-51

The machine never boots from the system ROM. UnSP::Reset takes the program counter from 0xFFF7, and the FIQ, IRQ n and BREAK vectors are read from 0xFFF6, 0xFFF8+n and 0xFFF5; all four sit in bank 0, which ExtRead answers from the cartridge under every decode mode. The system ROM sits on bank 3 and is reachable only once cartridge code selects decode mode 2 or 3; extmem_ctrl_ resets to 0x0028, which is decode 0, so nothing but the cartridge is mapped at power on. ref: unsp.cpp:49,67,77,253, spg200.cpp:188-209, spg200.cpp:37

Absent a file the constructor synthesises the region: 0x100000 words zero filled, with 0x0031 written into the odd word of each pair across 0xFFFC0-0xFFFDB so that calls into the BIOS land on zeroed memory. LoadSysrom replaces it, reading the image as little-endian 16-bit words and clamping at 0x100000 words, and runs only when bytes were passed. ref: vsmile.cpp:273-283, vsmile.cpp:326-334, jni_bridge.cpp:34-40

Two paths reach LoadSysrom and one of them checks nothing. The BIOS button imports through a file picker: validateBios demands exactly 0x200000 bytes and nine of the eleven words at 0xFFF5-0xFFFF decoding inside 0x0100-0xFFF0, tries both byte orders, rewrites the image to little-endian when the swapped reading scores higher, and stores the result as sysrom.bin in the app's private directory. With no imported file the ROM folder is searched instead: any entry whose extension is bin, rom or vsmile and whose lowercased name holds bios, sysrom or system rom, or begins with vsmile_v, is taken as the system ROM and handed over unmeasured, the last match in directory order winning. No hash is computed on either path. The three dumped revisions satisfy both tests as they stand, scoring eleven of eleven in both byte orders, so they load unswapped. ref: MainActivity.kt:31, MainActivity.kt:34, MainActivity.kt:215-236, MainActivity.kt:238-261, MainActivity.kt:277-288, EmuActivity.kt:156-168

Region is a jumper, never a file. Port C carries the region code in its low nibble and the intro jumper in bit 4. The code is fixed at 0xF and SetRegion has no caller, so one image serves every session; the jumper is exposed only as the Game intros setting, passed through nativeInit. ref: vsmile.cpp:365-369, vsmile.h:76, vsmile.h:77, vsmile.h:116, jni_bridge.cpp:39, MainActivity.kt:309,320

The system ROM has no directory of its own. The validated copy is written by the app into private storage, which the user cannot reach, so the one placement open to a collection is the folder chosen with ROM folder, beside the cartridge dumps. ref: MainActivity.kt:34, MainActivity.kt:154-168, MainActivity.kt:263-288

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

vsmile_v103.bin optional in repo HLE fallback
V.Smile system ROM, revision 1.03

vsmile_v102.bin optional in repo HLE fallback
V.Smile system ROM, revision 1.02

vsmile_v100.bin optional in repo HLE fallback
V.Smile system ROM, revision 1.00

Generated on 2026-08-23T16:12:06Z