slinky

splat link yutility

Linker script generator

Table of contents

• slinky
  • Table of contents
  • What is slinky?
    • Why use slinky instead of other linker scripts generators?
  • Features
    • Planned features
  • Installing
  • Versioning and changelog

What is slinky?

slinky is a linker script generator for modern GNU (ld) and LLVM (lld) linkers. It aims to be resuable and general enough so it can be used in a variety of projects

Its main purpose is to generate linker scripts for matching decompilation projects that use either of those linkers, allowing to still generate matching binary output but adding extra quality of life features.

Why use slinky instead of other linker scripts generators?

Other linker script generators are functional and do their job, but can be rather limited or lack some features due to a number of reasons.

Two notable linker script generators on this context are splat and mkldscript (which lives inside the OoT decompilation repo and the MM decompilation repo). These two are great at their job but can be a bit annoying to work with when you use them for their intended matching mindset. For example, mkldscript doesn't have many customization options besides what has been needed to produce matching builds of the Zelda64 games, it uses a non-standard and non-documented file format as input to describe the layout of the built ROM, and since it lives inside the game's repo then other projects using it can get out of date quite easily. splat on the other side is a lot much more customizable and is a Python library so it can be used by many different projects, but its main purpose is as a binary splitting tool, meaning its input file describes the binary blob that's meant to be splitted, making it hard to produce builds with modified contents (add or remove files, move the memory layout, etc).

slinky aims to provide extra quality of life features on top of the features that other linker scripts offer, like a better modding support experience or extra shiftability features not present on other tools.

Features

• Linker script generation for modern GNU ld and LLVM lld.
• Reusable library.
  • A CLI is also available.
• Support for conditional including/excluding of file entries.
  • Allows to decide which entries should (or shouldn't) be emitted by slinky.
  • Useful for multiversion support.
• Support for replacement strings in paths.
• Allow specifying multiple "segments" required for N64 games.
  • Support for partial linking, allowing to partially link each individual segment, improving build times.
• "Single segment" support.
  • Generated linker script will resemble more a traditional linker script, each elf section mapping a normal section.
• Allow specifying custom sections and customizing the order of the sections.
  • Sections can be changed globally and/or per segment.
  • Sections of specific file entries can be changed too.
• Documented custom file format.
• Multiple alignment options: SUBALIGN, align segments start and end, align individual sections, etc.
• Generation of Makefile dependency (.d) files.
• Emit linker script symbols to allow referencing the individual segments and sections from the final built elf.
  • Two customization options for linker symbols, the splat format and the Makerom format.
  • Generation of C header file containing all the generated linker symbols. The types of these symbols on this header can be customized too.
• Support for custom list of allowed and denied elf sections.
  • Useful to cherry pick which debugging sections should be allowed.
• Archive (.a) libraries support.
  • Support for both listing a library and letting the linker grab any used file or to specify which speicific files should be linked by the linker.
• Support splat's "vram classes" for better memory layout management.
• Support emitting custom symbols and requiring some symbols to be defined on during linking.
• Support for defining a shiftable _gp for small data support.
• Support for defining the entrypoint of the executable.
• Support for defining asserts to ensure the sanity of the build.
• Support emitting KEEPs attributes for file entries, allowing for a more flexible link time garbage collection.

Planned features

All the planned features are added to the issue tracker. A full list can be seen here

Installing

Prebuilt binaries for the latest version of the CLI are available at the releases page on Github.

The CLI can also be installed system-wide using Rust's cargo.

cargo install slinky-cli

To use the library itself as part of a Rust project then simply add it to your project with cargo.

Versioning and changelog

This library follows Semantic Versioning. We try to always keep backwards compatibility, so no breaking changes should happen until a major release (i.e. jumping from 1.X.X to 2.0.0).

To see what changed on each release check either the CHANGELOG.md file or check the releases page on Github. You can also use this link to check the latest release.