emulator: Skyline
type: standalone
core_classification: other
source: "https://archive.softwareheritage.org/browse/revision/dc20a615275f66bee20a4fd851ef0231daca4f14/"
upstream: "https://archive.softwareheritage.org/browse/revision/dc20a615275f66bee20a4fd851ef0231daca4f14/"
profiled_date: "2026-08-12"
source_commit: "dc20a615275f66bee20a4fd851ef0231daca4f14"
core_version: "0.0.3"
display_name: "Nintendo - Switch (Skyline)"
cores:
  - "skyline"
  - "SKYLINE"
systems:
  - nintendo-switch
mode: standalone

notes: |
  The GitHub repository skyline-emu/skyline was replaced by an archival notice on
  2026-08-18, so the pinned revision is served by Software Heritage; the same tree
  is in the archive.org bundle github.com_skyline-emu_bundles_20230508, and the
  signed edge-69 APK carries the built assets. Every path below reads against
  that revision.

  Nintendo Switch emulator for ARMv8 Android, written from scratch in C++ and Kotlin.
  Android package skyline.emu, versionCode 3, minSdk 29, with the debug variant taking a
  .dev suffix (build.gradle:23,28-29,120-121). ES-DE reaches it through its SKYLINE find
  rule and starts it with android.intent.action.VIEW on the content URI of the game.
  Development ceased and the README at the pinned commit records it; the code is split
  across skyline and skyline-dev, whose external file surface is identical (key_store.cpp
  :10-13 and shared_font_core.h:40-47 in both).

  NCA, NRO, NSO, NSP and XCI are loaded (loader/). Two key files are read, from keys/
  under the application internal files directory, which os.cpp:35 hands to the key store
  as its root. Both arrive through the in-app importer, which accepts only the two names
  and rewrites the trimmed pairs into that directory (KeyReader.kt:25-26,56-60); nothing
  else is consulted for keys, and there is no dev.keys or console.keys path.

  No firmware is installed and none is read. The system version is answered from a
  hardcoded 9.0.0-4.0 structure (ISystemSettingsServer.cpp:9-10) and the system data
  archives a game asks for through OpenDataStorageByDataId are served as stub RomFS
  images from the application assets (IFileSystemProxy.cpp:84-90). Two are carried:
  0100000000000806, the NgWord filter, holding 0.txt through 15.txt plus common.txt and
  version.dat, and 0100000000000823, NgWord2, holding ac_<0-15>_b1_nx, ac_<0-15>_b2_nx
  and ac_<0-15>_not_b_nx. A data id without a matching asset opens nothing.

  The six shared fonts are the one place where a firmware file replaces a built-in one.
  Each is looked for in fonts/ under the application external files directory, which
  resolves to /storage/emulated/0/Android/data/skyline.emu/files/ (SkylineApplication.kt
  :19,41), and only when it is absent does the asset of the same name serve instead
  (shared_font_core.h:40-47). The emulator writes the shared font header itself, a magic
  followed by the length XORed with a key derived at shared_font_core.h:36-38, and then
  copies the whole file after it (shared_font_core.h:51-55), so the file it expects is
  the raw TTF payload rather than the headered form the firmware stores. Sizes are taken
  from the file and never checked, and the six together have to fit the 0x140A000 shared
  memory block.

  A custom Vulkan driver can be loaded through adrenotools from gpu_drivers/<label>/
  under the internal files directory (gpu.cpp:342-357). The label and the library
  filename are both read from a meta.json inside the archive the user installs
  (GpuDriverHelper.kt:19-22,150-191,219), so the code names no driver file of its own;
  loading falls back to the built-in driver and then to the system libvulkan.so. Save
  data and the emulated SD card live under switch/ in the external files directory
  (IFileSystemProxy.cpp:21,67) and are written by the emulator.

files:
  - name: prod.keys
    path: "keys/prod.keys"
    system: nintendo-switch
    required: true
    description: "Production keys for content decryption"
    note: >-
      Read as name=value pairs from keys/ under the application internal files directory.
      Supplies header_key, and the titlekek_XX, key_area_key_application_XX,
      key_area_key_ocean_XX and key_area_key_system_XX generation-indexed sets. An
      encrypted NCA without header_key fails with MissingHeaderKey, and one whose key
      area cannot be unwrapped fails with MissingKeyArea, so no retail title loads
      without this file. The importer accepts a pair only when the name contains an
      underscore and the value is hexadecimal.
    source_ref: "app/src/main/cpp/skyline/os.cpp:35 (root directory), app/src/main/cpp/skyline/crypto/key_store.cpp:12-13 (read), app/src/main/cpp/skyline/crypto/key_store.h:30-39 (key names), app/src/main/cpp/skyline/crypto/key_store.cpp:46-62 (parse), app/src/main/cpp/skyline/vfs/nca.cpp:21-22,126 (failures), app/src/main/java/emu/skyline/KeyReader.kt:83-88 (import check)"

  - name: title.keys
    path: "keys/title.keys"
    system: nintendo-switch
    required: false
    description: "Per-title keys"
    note: >-
      Read as rights id to title key pairs from the same directory. A title key normally
      arrives instead from the .tik tickets carried inside an NSP, which are parsed and
      pushed into the same store, so this file is only needed when no ticket supplies
      one; that case fails with MissingTitleKey. The importer requires both halves of a
      pair to be 32 hexadecimal characters.
    source_ref: "app/src/main/cpp/skyline/crypto/key_store.cpp:10-11 (read), app/src/main/cpp/skyline/crypto/key_store.cpp:35-39 (parse), app/src/main/cpp/skyline/loader/nsp.cpp:14-21 (tickets), app/src/main/cpp/skyline/vfs/nca.cpp:108-110 (failure), app/src/main/java/emu/skyline/KeyReader.kt:77-82 (import check)"

  - name: FontStandard.ttf
    path: "fonts/FontStandard.ttf"
    system: nintendo-switch
    required: false
    has_builtin: true
    description: "Shared font, standard"
    note: >-
      Loaded from fonts/ under the application external files directory when present,
      otherwise from the asset of the same name, which carries Noto Sans CJK. Copied
      into the shared font block behind a header the emulator generates, so the expected
      content is the raw TTF payload.
    source_ref: "app/src/main/cpp/skyline/services/pl/shared_font_core.h:26 (entry), :40-47 (lookup and fallback), :51-55 (header and copy)"

  - name: FontChineseSimplified.ttf
    path: "fonts/FontChineseSimplified.ttf"
    system: nintendo-switch
    required: false
    has_builtin: true
    description: "Shared font, simplified Chinese"
    note: >-
      Same lookup as the standard font, with a Noto Sans CJK asset behind it.
    source_ref: "app/src/main/cpp/skyline/services/pl/shared_font_core.h:27 (entry), :40-47 (lookup and fallback), :51-55 (header and copy)"

  - name: FontExtendedChineseSimplified.ttf
    path: "fonts/FontExtendedChineseSimplified.ttf"
    system: nintendo-switch
    required: false
    has_builtin: true
    description: "Shared font, extended simplified Chinese"
    note: >-
      Same lookup as the standard font, with a Noto Sans CJK asset behind it.
    source_ref: "app/src/main/cpp/skyline/services/pl/shared_font_core.h:28 (entry), :40-47 (lookup and fallback), :51-55 (header and copy)"

  - name: FontChineseTraditional.ttf
    path: "fonts/FontChineseTraditional.ttf"
    system: nintendo-switch
    required: false
    has_builtin: true
    description: "Shared font, traditional Chinese"
    note: >-
      Same lookup as the standard font, with a Noto Sans CJK asset behind it.
    source_ref: "app/src/main/cpp/skyline/services/pl/shared_font_core.h:29 (entry), :40-47 (lookup and fallback), :51-55 (header and copy)"

  - name: FontKorean.ttf
    aliases:
      - FontNintendoExtended.ttf
    path: "fonts/FontKorean.ttf"
    system: nintendo-switch
    required: false
    has_builtin: true
    description: "Shared font, Korean"
    note: >-
      Same lookup as the standard font. The asset behind it is Roboto Medium,
      byte-identical to FontNintendoExtended.ttf since the switch to Roboto
      for the Korean font.
    source_ref: "app/src/main/cpp/skyline/services/pl/shared_font_core.h:30 (entry), :40-47 (lookup and fallback), :51-55 (header and copy)"

  - name: FontNintendoExtended.ttf
    path: "fonts/FontNintendoExtended.ttf"
    system: nintendo-switch
    required: false
    has_builtin: true
    description: "Shared font, extended button glyphs"
    note: >-
      Same lookup as the standard font, with a Roboto asset behind it.
    source_ref: "app/src/main/cpp/skyline/services/pl/shared_font_core.h:31 (entry), :40-47 (lookup and fallback), :51-55 (header and copy)"

  - name: "0100000000000806"
    path: "romfs/0100000000000806"
    system: nintendo-switch
    required: false
    bundled: true
    description: "NgWord system data archive"
    note: >-
      Stub RomFS image served from the application assets when a game opens the data
      storage for this title id. Holds 0.txt through 15.txt, common.txt and version.dat.
    source_ref: "app/src/main/cpp/skyline/services/fssrv/IFileSystemProxy.cpp:84-90"

  - name: "0100000000000823"
    path: "romfs/0100000000000823"
    system: nintendo-switch
    required: false
    bundled: true
    description: "NgWord2 system data archive"
    note: >-
      Stub RomFS image served from the application assets when a game opens the data
      storage for this title id. Holds ac_<0-15>_b1_nx, ac_<0-15>_b2_nx and
      ac_<0-15>_not_b_nx.
    source_ref: "app/src/main/cpp/skyline/services/fssrv/IFileSystemProxy.cpp:84-90"

  - name: binaryList.txt
    path: "tzdata/binaryList.txt"
    system: nintendo-switch
    required: false
    bundled: true
    description: "Time zone location list"
    note: >-
      Read from the application assets at time service init and used as the list of
      known locations. It names the 594 zone binaries under tzdata/zoneinfo/, each of
      which is opened by location name when a zone rule is loaded. The set is generated
      from tzdb 2021a in Horizon format.
    source_ref: "app/src/main/cpp/skyline/services/timesrv/core.cpp:272 (list), :293 (zone binary by name), app/src/main/cpp/skyline/services/glue/ITimeZoneService.cpp:29,56 (zone binary by requested location)"

  - name: version.txt
    path: "tzdata/version.txt"
    system: nintendo-switch
    required: false
    bundled: true
    description: "Time zone data version"
    note: >-
      Read from the application assets at time service init and reported as the time
      zone binary version.
    source_ref: "app/src/main/cpp/skyline/services/timesrv/core.cpp:289"

  - name: profile_picture.jpeg
    system: nintendo-switch
    required: false
    bundled: true
    description: "Default user profile image"
    note: >-
      Opened from the application assets when a game asks the account service for the
      profile image of the emulated user.
    source_ref: "app/src/main/cpp/skyline/services/account/IProfile.cpp:66"

  - name: blit.vert.spv
    path: "shaders/blit.vert.spv"
    system: nintendo-switch
    required: false
    bundled: true
    description: "Blit vertex helper shader"
    note: >-
      Opened from the application assets when the GPU helper shaders are built. Compiled
      at build time from app/src/main/shaders/blit.vert.
    source_ref: "app/src/main/cpp/skyline/gpu/shaders/helper_shaders.cpp:201, app/src/main/cpp/skyline/gpu.cpp:403 (asset filesystem)"

  - name: blit.frag.spv
    path: "shaders/blit.frag.spv"
    system: nintendo-switch
    required: false
    bundled: true
    description: "Blit fragment helper shader"
    note: >-
      Opened from the application assets when the GPU helper shaders are built. Compiled
      at build time from app/src/main/shaders/blit.frag.
    source_ref: "app/src/main/cpp/skyline/gpu/shaders/helper_shaders.cpp:201, app/src/main/cpp/skyline/gpu.cpp:403 (asset filesystem)"

  - name: clear.vert.spv
    path: "shaders/clear.vert.spv"
    system: nintendo-switch
    required: false
    bundled: true
    description: "Clear vertex helper shader"
    note: >-
      Opened from the application assets when the GPU helper shaders are built. Compiled
      at build time from app/src/main/shaders/clear.vert.
    source_ref: "app/src/main/cpp/skyline/gpu/shaders/helper_shaders.cpp:328, app/src/main/cpp/skyline/gpu.cpp:403 (asset filesystem)"

  - name: clear.frag.spv
    path: "shaders/clear.frag.spv"
    system: nintendo-switch
    required: false
    bundled: true
    description: "Clear fragment helper shader"
    note: >-
      Opened from the application assets when the GPU helper shaders are built. Compiled
      at build time from app/src/main/shaders/clear.frag.
    source_ref: "app/src/main/cpp/skyline/gpu/shaders/helper_shaders.cpp:328, app/src/main/cpp/skyline/gpu.cpp:403 (asset filesystem)"