emulator: SquirrelJME
type: libretro
source: "https://github.com/SquirrelJME/SquirrelJME"
profiled_date: "2026-03-18"
core_version: "0.3.0"
display_name: "Java ME (SquirrelJME)"
cores: [squirreljme]
systems: [j2me]
verification: existence
notes: |
  Java ME 8 virtual machine for libretro. Runs J2ME MIDlets and older flip-phone games.
  The core needs a class library JAR placed in RetroArch's system directory.
  It searches for the JAR using a priority list: versioned-fast first, then versioned,
  then unversioned variants. The first match wins.

  Search order (from nanocoat/src/boot.c sjme_nvm_romNames[]):
    1. squirreljme-{version}-fast.jar
    2. squirreljme-{version}.jar
    3. squirreljme-{version}-test.jar
    4. squirreljme-{version}-slow.jar
    5. squirreljme-{version}-slow-test.jar
    6. squirreljme-fast.jar
    7. squirreljme.jar
    8. squirreljme-test.jar
    9. squirreljme-slow.jar
    10. squirreljme-slow-test.jar

  Current version: 0.3.0. All firmware entries are marked optional in the .info file
  because the core can launch its built-in modeless stars demo without a class library.
  For actual J2ME software, one of these JARs is required.

  The class library JAR is built from the SquirrelJME project itself (not a third-party
  BIOS dump). It is open source under MPL-2.0.

files:
  # -- Versioned JARs (v0.3.0, preferred) --

  - name: "squirreljme-0.3.0-fast.jar"
    description: "SquirrelJME class library v0.3.0 (fast/optimized build)"
    required: false
    bundled: false
    source_ref: "nanocoat/src/boot.c:102, squirreljme_libretro.info:firmware5"
    note: "Highest priority versioned JAR. Optimized runtime, recommended for normal use."

  - name: "squirreljme-0.3.0.jar"
    description: "SquirrelJME class library v0.3.0 (standard build)"
    required: false
    bundled: false
    source_ref: "nanocoat/src/boot.c:103, squirreljme_libretro.info:firmware4"
    note: "Standard versioned build. Second in search priority."

  - name: "squirreljme-0.3.0-slow.jar"
    description: "SquirrelJME class library v0.3.0 (slow/interpreter build)"
    required: false
    bundled: false
    source_ref: "nanocoat/src/boot.c:105, squirreljme_libretro.info:firmware6"
    note: "Pure interpreter mode, no optimizations. Useful for debugging."

  - name: "squirreljme-0.3.0-slow-test.jar"
    description: "SquirrelJME class library v0.3.0 (slow build with tests)"
    required: false
    bundled: false
    source_ref: "nanocoat/src/boot.c:106, squirreljme_libretro.info:firmware7"
    note: "Interpreter mode with built-in test suites."

  # -- Unversioned JARs (fallback) --

  - name: "squirreljme-fast.jar"
    description: "SquirrelJME class library (fast/optimized, unversioned)"
    required: false
    bundled: false
    source_ref: "nanocoat/src/boot.c:107, squirreljme_libretro.info:firmware1"
    note: "Highest priority unversioned JAR. Renamed from a versioned build."

  - name: "squirreljme.jar"
    description: "SquirrelJME class library (standard, unversioned)"
    required: false
    bundled: false
    source_ref: "nanocoat/src/boot.c:108, squirreljme_libretro.info:firmware0"
    note: "Most common filename. If only one JAR is provided, use this name."

  - name: "squirreljme-slow.jar"
    description: "SquirrelJME class library (slow/interpreter, unversioned)"
    required: false
    bundled: false
    source_ref: "nanocoat/src/boot.c:110, squirreljme_libretro.info:firmware2"
    note: "Pure interpreter, unversioned."

  - name: "squirreljme-slow-test.jar"
    description: "SquirrelJME class library (slow with tests, unversioned)"
    required: false
    bundled: false
    source_ref: "nanocoat/src/boot.c:111, squirreljme_libretro.info:firmware3"
    note: "Interpreter with tests, unversioned."