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Executable formats

FruityOS uses one executable suffix per target platform. Pish resolves bare program names by appending only the suffix associated with $platform.

Platform Suffix Native format
Linux x86-64 .elf Static ELF64 executable
Windows x86-64 .exe PE32+ console executable
FruityOS x86-64 .fap Flat FruityOS application image

Linux ELF

Orgasm first emits a raw static ELF image. The normal linker compresses that image with Juicer and appends the compressed stream to a small ELF launcher.

At startup the launcher:

  1. maps executable memory at 0x400000;
  2. decodes the original ELF image into that mapping;
  3. reads the reconstructed ELF entrypoint;
  4. restores the native process stack; and
  5. transfers control to the payload.

The resulting file keeps the .elf suffix even though it contains both the launcher and the compressed inner image.

Windows PE32+

Windows programs are one-section PE32+ console images with no CRT and no import library. Pith reachability determines which kernel32.dll wrappers and imports are included.

The normal linker compresses the original PE with Juicer and appends it to a small PE32+ launcher. The launcher:

  1. opens its own executable;
  2. reads and decodes the appended payload;
  3. allocates memory at the payload's preferred image base;
  4. copies the reconstructed PE image;
  5. resolves its imports with LoadLibraryA and GetProcAddress; and
  6. enters the inner PE entrypoint.

Both the launcher and reconstructed payload are native x86-64 PE32+ images.

FruityOS FAP

A .fap is a flat FruityOS application entered at its first byte. The FruityOS startup and runtime adapt Jabara's calling convention to the FruityOS syscall ABI. Normal linked FAPs may contain a Juicer-compressed payload, but they do not need an ELF or PE container.

Stage0 images

The first JBC and current Orgasm executables reconstructed under stage0/ are intentionally uncompressed. Juicer and Concat are themselves outputs of the bootstrap and cannot be prerequisites of those first executables.

See Build system for the platform link pipelines and Toolchains for compiler and assembler behavior.