Build the Cross-Toolchain

Before continue: Check twice that you are NOT root! (Especially before each 'make install')

The chapter 5 of the book can be skipped. Instead we build a musl based cross toolchain. There are 2 alternatives: musl-cross-make and mussel. The latter is more up-to-date, thus it's the recommended choice. Download it and extract it in the home of the lfs user. Change into the directory (usually called  mussel-master ). Run  ./check.sh  and install the missing packages. Then open  ./mussel.sh  in an editor and change the value of the following two variables to:

MPREFIX="/_tools"
MSYSROOT="/_tools"

Alternative apply this patch. Then build and install it with

sudo ./mussel.sh x86_64 -l -o

This takes a while. If finished change ownership of the top level directory to the lfs user, move it to the $LFS directory and create a symlink:

chown -R lfs.users /_tools
mv /_tools $LFS/_tools
sudo ln -s $LFS/_tools /_tools

The new cross compiler has built-in specs which refer to the musl dynamic loader  /lib/ld-musl-x86_64.so.1 . We have to adjust this to reflect the filesystem layout of the target system which is  /qlnx/lib/ld-musl-x86_64.so.1 . This will be reached by creating a modified  specs  file in the proper location:

/_tools/bin/x86_64-linux-musl-gcc -dumpspecs | sed 's/\/lib\/ld-musl/\/qlnx\/lib\/ld-musl/g' > /_tools/lib/gcc/x86_64-linux-musl/11.2.0/specs

Now it have to verified that all works like expected.

Test It

$> cd $LFS
$> printf "#include <stdio.h>\nint main(){}\n" > dummy.c
$> $LFS_TGT-gcc dummy.c
$> readelf -l a.out | grep ld

The output HAVE TO be:

      [Requesting program interpreter: /qlnx/lib/ld-musl-x86_64.so.1]

Otherwise stop here and investigate. If everything is ok delete  a.out .

Install Header Files

We can use the “fresh” header files “created” by  mussel.sh . It doesn't make any significant difference to extract and install them again. Copy the headers from the mussel toolchain:

cp -vr /_tools/usr/include /qlnx/inc