Command explanations
make -e: The -e paramater tells make that
environment variables take precedence over variables defined in the
Makefile file(s). This is needed in order to successfully link binutils
statically.
LDFLAGS=-all-static: Setting the variable LDFLAGS
to the value -all-static causes binutils to be linked statically.
tooldir=$LFS/usr: Normally the tooldir (the
directory where the executables from binutils end up in) is set to
$(exec_prefix)/$(target_alias) which expands into, for example,
/usr/i686-pc-linux-gnu. Since we only build for our own system we don't
need this target specific directory in $LFS/usr. You would use that
setup if you use your system to cross-compile (for example you would
compile a package on your Intel machine that generates code that can be
executed on Apple PowerPC machines).