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Building a toolchain from source

This document contains information on building an i386-elf toolchain from source. However, these instructions are not likely to work correctly if your host system compiler is a recent (as of Spring 2024) version of gcc, which is almost certainly the case if you’re using a recent version of Linux or MacOS. Therefore, rather than building a toolchain from source, we strongly recommend that you install a prebuilt toolchain. These instructions remain here for posterity.

2.1: Test Your Compiler Toolchain

The compiler toolchain is a collection of tools that turns source code into binary executables for a target architecture. Pintos is written in C and x86 assembly, and runs on 32-bit x86 machines. So we will need the appropriate C compiler (gcc), assembler (as), linker (ld), and debugger (gdb).

If you are using a Linux machine, it is likely equipped with the compiler toolchain already. But it should support 32-bit x86 architecture. A quick test of the support is to run objdump -i | grep elf32-i386 in the terminal. If it returns matching lines, your system’s default tool chain supports the target, then you can skip Section 2.2. Otherwise, you will need to build the toolchain from source.

2.2: Build Toolchain from Source

When you are building the toolchain from source, to distinguish the new toolchain from your system’s default one, you should add a i386-elf- prefix to the build target, e.g., i386-elf-gcc, i386-elf-as.

2.2.1 Prerequisite

• Standard build tools including make, gcc, etc. To build GDB, you will need the ncurses and texinfo libraries.

• For Ubuntu, you can install these packages with

  sudo apt-get install build-essential automake git libncurses5-dev texinfo

• For macOS, first you should have the command-line tools in Xcode installed:

  xcode-select --install

  You can then install ncurses and texinfo with brew:

  brew install ncurses texinfo

2.2.2 The Easy Way

Replace /path/to/setup below with a real path to store the toolchain source and build, e.g., /home/ryan/318/toolchain; and replace /path/to/pintos with the real path where you cloned the pintos repo, e.g., ~/318/pintos.

SWD=/path/to/setup
mkdir -p $SWD
cd /path/to/pintos
src/misc/toolchain-build.sh $SWD

If the above commands succeeded, add the toolchain path to your PATH environment variable settings in the .bashrc (or .zshrc if you are using zsh) file in your home directory.

export PATH=$SWD/x86_64/bin:$PATH

Don’t forget to replace the $SWD above with the real path, e.g., export PATH=/home/ryan/318/toolchain/x86_64/bin:$PATH.

For the Hardcores:

If you are curious to build the toolchain manually, below are the detailed instructions.

1. Directory and environment variables:
   • Create a setup directory (e.g., ~/318/toolchain) and subdirectories that look like this:

     /path/to/setup
     ├── build
     ├── x86_64
     └── src
     

   • Set the environment variables (remember to replace /path/to/setup with the full path to the actual setup directory you’ve created, e.g., SWD=/home/ryan/318/toolchain).

     SWD=/path/to/setup
     PREFIX=$SWD/x86_64
     export PATH=$PREFIX/bin:$PATH
     export LD_LIBRARY_PATH=$PREFIX/lib:$LD_LIBRARY_PATH

     For Mac users, the last command is

     export DYLD_LIBRARY_PATH=$PREFIX/lib:$DYLD_LIBRARY_PATH

     instead.

2. GNU binutils:
   • Download:

     cd $SWD/src 
     wget https://ftp.gnu.org/gnu/binutils/binutils-2.27.tar.gz && tar xzf binutils-2.27.tar.gz

   • Build:

     mkdir -p $SWD/build/binutils && cd $SWD/build/binutils
     ../../src/binutils-2.27/configure --prefix=$PREFIX --target=i386-elf --disable-multilib --disable-nls --disable-werror
     make -j8
     make install

3. GCC:
   • Download:

     cd $SWD/src
     wget https://ftp.gnu.org/gnu/gcc/gcc-6.2.0/gcc-6.2.0.tar.bz2 && tar xjf gcc-6.2.0.tar.bz2
     cd $SWD/src/gcc-6.2.0 && contrib/download_prerequisites

   • Build:

     mkdir -p $SWD/build/gcc && cd $SWD/build/gcc
     ../../src/gcc-6.2.0/configure --prefix=$PREFIX --target=i386-elf --disable-multilib --disable-nls --disable-werror --disable-libssp --disable-libmudflap --with-newlib --without-headers --enable-languages=c,c++
     make -j8 all-gcc 
     make install-gcc
     make all-target-libgcc
     make install-target-libgcc

4. GDB:
   • Download:

     cd $SWD/src
     wget https://ftp.gnu.org/gnu/gdb/gdb-7.9.1.tar.xz  && tar xJf gdb-7.9.1.tar.xz

   • Build:

     mkdir -p $SWD/build/gdb && cd $SWD/build/gdb
     ../../src/gdb-7.9.1/configure --prefix=$PREFIX --target=i386-elf --disable-werror
     make -j8
     make install

2.2.3 Verify Installation {#223-verify-installation}

Now check if the toolchain has been installed to the proper place and the version is 6.2.0:

which i386-elf-gcc
i386-elf-gcc --version