Diablo Toolchains

This repository provides a script able to build a number of toolchains that produce Diablo-compatible binaries. The supported combinations can be listed by executing the commad ./build.sh -h.

Please note that when building an LLVM toolchain the result will only use LLVM/clang to compile. Assembling and linking will still require a GCC/Binutils toolchain built with this script. We did however make the necessary fixes in order for the resulting clang compiler to invoke the Binutils tools without issues ( but with some required arguments ).

When using the built toolchain some arguments are required to produce a rewriteable binary. The example directory contains two makefiles showing what extra arguments to pass when using a toolchain;

• When invoking GCC for ARM the linker needs the following arguments:

  -Wl,--no-merge-exidx-entries

• Clang needs these to be able to use Binutils for assembling and linking (with TRIPLET either being "arm-diablo-linux-gnueabi" or "i486-diablo-linux-gnu"):

  -isysroot $(TCPATH)/$(BINUTILSPREFIX)/sysroot -no-integrated-as -gcc-toolchain $(TCPATH) -ccc-gcc-name TRIPLET -target TRIPLET

• When compiling for x86 these arguments are needed with both Clang an GCC:

  -march=i486 -m32

Remark whenever you want to rewrite a binary with Diablo the object files have to be available. In order to enforce this make sure to pass the -save-temps flag when compiling.

Repository Overview

None of the files in the following directories should be changed in order to build a toolchain. Only modify them if you know what you are doing.

• diablo-patches This directory contains all our patches for the different versions of GCC, LLVM, EGLIBC and Binutils. The patches found in here are applied when building a toolchain that uses the corresponding versions of the tools.

• config A collection of all our crosstool-ng configuration files. One such file can be found in here for each supported toolchain version.

• example This folder contains an example 'Hello World'-project with makefiles for i486 and arm. The makefiles are set up with all the necessary options to compile for and rewrite with Diablo.

• package This directory contains some templates for building Debian packages of the toolchains.

Prerequisites

The following packages are assumed to be installed on the system where you want to build tool chains:

• gperf
• flex
• bison
• g++
• libncurses-dev
• subversion
• git

On Debian-based Linux distributions, these packages can be installed like this:

sudo apt-get install gperf flex bison g++ libncurses-dev subversion git

Usage

All the required functionality implemented in this repository is accessible through a single shell script, build.sh, in the root of this repository. Documentation on how this script should be invoked can be retrieved by running the following command:

./build.sh -h

Example

The followig command generates a Diablo-compatible GCC 4.8.1/binutils 2.22 toolchain for generating i486-compatible binaries:

./build.sh -a i486 -d /opt/my-toolchain -c 0 -n 5