libRuntime

The primary goal of this repository is to provide a framework for creating statically linked AppImage runtimes.

The code from this repository is currently a copy-paste of the AppImageKit runtime with some refactoring (including fixing all the compiler warnings).

Building

To build the default, completely statically linked runtime, pass --wrap-mode=forcefallback to the Meson setup command. This causes Meson to pull all dependencies as subprojects and build them from source (as static libraries).

meson --wrap-mode=forcefallback -Ddefault_library=static build
ninja -C build

To reduce the file size of the generated runtime image, the use of musl libc is recommended.

Using libRuntime to build a custom AppImage runtime

To use libRuntime for your runtime, generate a .wrap file for this project and include it in your subproject folder. Then the libRuntime library as well as the patch program for the executable can be obtained like this:

# more code ...

# Required programs for the patcher script
dd_prog      = find_program('dd')
objcopy_prog = find_program('objcopy')

# Build libRuntime
libruntime_sp  = subproject('libruntime')
libruntime_dep = libruntime_sp.get_variable('libruntime_dep')
patcher_prog   = libruntime_sp.get_variable('patcher_prog')

# Build the unpatched executable
foo_raw = executable(
    'foo_raw', ['foo.c'],
    dependencies: [libruntime_dep],
)

# Patch the executable
custom_target(
    'patch_runtime',
    input:       [foo_raw],
    output:      ['foo'],
    install:     true,
    install_dir: get_option('bindir'),
    command: [
        patcher_prog,
        '-i', '@INPUT@',
        '-o', '@OUTPUT@',
        '-p', '@PRIVATE_DIR@',
        '--dd', dd_prog,
        '--objcopy', objcopy_prog,
    ],
)

# more code ...

See the default runtime code for how to use libRuntime.