Linux From Scratch - Version SVN-20150308

Chapter 5. Constructing a Temporary System

5.4. Binutils-2.25 - Pass 1

The Binutils package contains a linker, an assembler, and other tools for handling object files.

Approximate build time: 1 SBU
Required disk space: 545 MB

5.4.1. Installation of Cross Binutils

[Note]

Note

Go back and re-read the notes in the previous section. Understanding the notes labeled important will save you a lot of problems later.

It is important that Binutils be the first package compiled because both Glibc and GCC perform various tests on the available linker and assembler to determine which of their own features to enable.

The Binutils documentation recommends building Binutils outside of the source directory in a dedicated build directory: 

mkdir -v ../binutils-build
cd ../binutils-build
[Note]

Note

In order for the SBU values listed in the rest of the book to be of any use, measure the time it takes to build this package from the configuration, up to and including the first install. To achieve this easily, wrap the commands in a time command like this: time { ./configure ... && ... && make install; }.

[Note]

Note

The approximate build SBU values and required disk space in Chapter 5 does not include test suite data.

Now prepare Binutils for compilation: 

../binutils-2.25/configure     \
    --prefix=/tools            \
    --with-sysroot=$LFS        \
    --with-lib-path=/tools/lib:/tools/libx32:/tools/lib32 \
    --target=$LFS_TGT          \
    --disable-nls              \
    --disable-werror           \
    --enable-64-bit-bfd

The meaning of the configure options:

--prefix=/tools

This tells the configure script to prepare to install the Binutils programs in the /tools directory.

--with-sysroot=$LFS

For cross compilation, this tells the build system to look in $LFS for the target system libraries as needed.

--with-lib-path=/tools/lib:/tools/libx32:/tools/lib32

This specifies which library paths the linker should be configured to use.

--target=$LFS_TGT

Because the machine description in the LFS_TGT variable is slightly different than the value returned by the config.guess script, this switch will tell the configure script to adjust Binutil's build system for building a cross linker.

--disable-nls

This disables internationalization as i18n is not needed for the temporary tools.

--disable-werror

This prevents the build from stopping in the event that there are warnings from the host's compiler.

--enable-64-bit-bfd

This adds 64 bit support to Binutils.

Continue with compiling the package: 

make

Compilation is now complete. Ordinarily we would now run the test suite, but at this early stage the test suite framework (Tcl, Expect, and DejaGNU) is not yet in place. The benefits of running the tests at this point are minimal since the programs from this first pass will soon be replaced by those from the second.

Create a symlink to ensure the sanity of the toolchain, and create the multilib library paths: 

case $(uname -m) in
  x86_64) mkdir -v /tools/lib && ln -sv lib /tools/lib64 ;;
esac
mkdir -v /tools/lib32
mkdir -v /tools/libx32

Install the package: 

make install

Details on this package are located in Section 6.13.2, “Contents of Binutils.”