Linux From Scratch - Version 20150528-dpkg

Chapter 5. Constructing a Temporary System

5.6. 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

5.6.1. Installation of Cross Binutils

It is important that Binutils be the first toolchain 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=$LFS        \
    --with-lib-path=/tools/lib \
    --target=$LFS_TGT          \
    --disable-nls              \
    --disable-werror

The meaning of the configure options:

--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

This specifies which library path 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.

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.

If building on x86_64, create a symlink to ensure the sanity of the toolchain: 

case $(uname -m) in
  x86_64) mkdir -pv debian/tmp/tools/lib &&
          ln -sv lib debian/tmp/tools/lib64 ;;
esac

Install the package to a temporary directory: 

make install DESTDIR=$(pwd)/debian/tmp

Build the package archive: 

PRESERVE_LIB64=1 buildpkg --package=binutils-pass1 --version=2.25

The meaning of the buildpkg parameters:

PRESERVE_LIB64=1

Setting this environment variable overrides the package fixup script which would normally remove the /tools/lib64 symlink when building on x86_64.

--version=2.25

Since the working directory name is binutils-build, the buildpkg script needs to be told the actual package version to use.

Install the package: 

dpkg -i ../binutils-pass1_2.25_*.deb

Details on this package are located in Section 6.16.2, “Contents of Binutils.”