🛠️ Legacy Toolchain: GCC 5.x + glibc 2.17 for x86_64-pc-linux-gnu (Runtime-Enabled)

This repository provides a cross-build toolchain for targeting glibc 2.17 on x86_64 using GCC 5.x. It is designed for building and running binaries on modern systems with full runtime support via sysroot redirection.

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📦 Binary Download

➡️ Download toolchain tarball

Contents:

• GCC 5.x cross toolchain
• glibc 2.17 runtime and development headers
• libstdc++, libgcc, and sysroot layout
• Example wrapper script for runtime execution

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✅ Use Case

Build and run legacy-compatible binaries on the same host, using glibc 2.17 and older ABI rules — without touching or downgrading the host system’s glibc.

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🧱 Toolchain Specs

Item	Value
Architecture	x86_64
Compiler	GCC 5.x
C library	glibc 2.17
Sysroot layout	Fully relocatable
Host Compatibility	Ubuntu ≥ 20.04, WSL2, etc.

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🚀 Quickstart

1. Extract the toolchain

mkdir -p $HOME/x-tools
tar -xJf x86_64-pc-linux-gnu-toolchain.tar.xz -C $HOME/x-tools/
export TOOLCHAIN_ROOT=$HOME/x-tools/x86_64-pc-linux-gnu

2. Build a program

export PATH="$TOOLCHAIN_ROOT/bin:$PATH"
x86_64-pc-linux-gnu-gcc -O2 -static-libgcc -static-libstdc++ -o hello hello.c

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🧪 Run the program (glibc 2.17 runtime)

To run binaries using glibc 2.17 instead of your host glibc:

Method 1: With LD_LIBRARY_PATH

export GLIBC217_LIB="$TOOLCHAIN_ROOT/x86_64-pc-linux-gnu/lib"
LD_LIBRARY_PATH="$GLIBC217_LIB:$LD_LIBRARY_PATH" ./hello

Method 2: Patchelf rpath override

patchelf --set-interpreter "$GLIBC217_LIB/ld-2.17.so" --set-rpath "$GLIBC217_LIB" ./hello
./hello

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🧰 Wrapper script (recommended)

Create a run-with-sysroot.sh:

#!/bin/bash
TOOLCHAIN="$HOME/x-tools/x86_64-pc-linux-gnu"
export LD_LIBRARY_PATH="$TOOLCHAIN/x86_64-pc-linux-gnu/lib:$LD_LIBRARY_PATH"
exec "$@"

Usage:

chmod +x run-with-sysroot.sh
./run-with-sysroot.sh ./hello

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🔧 Cross Configuration

This toolchain was built with Crosstool-NG using the config: .config

Key settings:

• GCC version: 5.5.0
• glibc version: 2.17
• Binutils: 2.26
• Enable C++ support: yes
• Enable threads: yes
• Sysroot: enabled and isolated

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📜 License

Toolchain components are covered by:

• GPLv2+/LGPL for GCC, glibc
• FLOSS-compatible licenses

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📬 Feedback

Issues and pull requests welcome! If you build variants (e.g. musl, static-only, ARM targets), feel free to contribute configs.