darwin-dyld-build

Build Apple's dyld_info and dyld_shared_cache_util tools from open source using the public macOS SDK.

Overview

Apple's dyld (dynamic linker) is open source, but the official source requires Apple's internal SDK to build. This project provides patches that enable building with the standard public Xcode SDK.

What's Included

Tool	Description
dyld_info	Analyze Mach-O binaries - segments, sections, symbols, fixups, etc.
dyld_shared_cache_util	Inspect and extract from the dyld shared cache

Installation

Homebrew (Recommended)

brew tap blacktop/tap
brew install dyld-tools

Download Binary

Download pre-built binaries from the Releases page.

Build from Source

git clone https://github.com/blacktop/darwin-dyld-build.git
cd darwin-dyld-build

# Interactive version selection (requires gum)
./build.sh

# Or specify version directly
MACOS=26.1 ./build.sh

Binaries will be in dist/.

Usage

dyld_info

Analyze Mach-O binaries:

# Show all info about a binary
dyld_info /usr/lib/libSystem.B.dylib

# Show specific information
dyld_info -segments /usr/bin/ls
dyld_info -exports /usr/lib/libc.dylib
dyld_info -fixups /usr/bin/clang

dyld_shared_cache_util

Inspect and extract from the shared cache:

# Path to shared cache (macOS 11+)
CACHE="/System/Volumes/Preboot/Cryptexes/OS/System/Library/dyld/dyld_shared_cache_arm64e"

# Show cache info
dyld_shared_cache_util -info $CACHE

# List all images in cache
dyld_shared_cache_util -list $CACHE

# Extract all dylibs
dyld_shared_cache_util -extract /tmp/extracted $CACHE

# Show exports
dyld_shared_cache_util -exports $CACHE

# Generate JSON map
dyld_shared_cache_util -json-map $CACHE > cache-map.json

Supported Versions

macOS	dyld Version	Status
26.1	dyld-1330	✓ Supported

More versions coming soon

License

The patches in this repository are provided under the MIT License.

The dyld source code itself is licensed under the Apple Public Source License 2.0.