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  * **lfs** 
  * **Jonathan Haack**
  * **Haack's Networking**
  * **netcmnd@jonathanhaack.com** 

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//Building a linux from scratch (lfs) system.// [in progress, see associated [[https://hc.jonathanhaack.com/oemb1905/lfs|Repository]].]

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First, set up the host system with min requirements

  sudo apt install bash binutils bison bzip2 coreutils diffutils findutils gawk gcc g++ grep m4 make patch perl sed tar texinfo xz-utils

Verify that the versions are good

  cd ~

Copy and paste the version-check.sh contents into your terminal, then run

  bash version-check.sh

Update or add anything missing, and if you need to symlink sh to bash that would be

  cd /bin/
  sudo ln -sf bash /bin/sh

Now check your libraries with library-check.sh, and remember it should have none of them or all of them only

  cd ~

Copy and paste the library-check.sh contents into your terminal, then run

  bash library-check.sh

We can now start preparing the partition for the LFS work

  sudo -i
  sudo apt install gparted
  sudo gparted

Inside gparted, create one partition.  In a future tutorial, I will do more than one partition.  Once set up, edit fstab

  sudo nano /etc/fstab
  
Here are some suggested defaults

  /dev/vda3     /media/lfs            ext4    defaults            1     1

Now that you have created that entry, add environment variables to .bashrc for your user and for your root

  nano ~/.bashrc
  nano /root/.bashrc  

In the file that opens, add this env variable to the body

  export LFS=/media/lfs

Reboot the system, make sure the external partition auto-mounts, and its location matches the output of

  echo $LFS

Ok, now we will create a sources directory on the partition and create a file called wget-list 

  mkdir -v $LFS/sources
  chmod -v a+wt $LFS/sources
  nano wget-list

In the file that opens, copy and paste the contents of http://www.linuxfromscratch.org/lfs/view/7.9/wget-list then execute this within same directory as above

  wget --input-file=wget-list --continue --directory-prefix=$LFS/sources

You can do similar trick with md5sum to ensure every download completed with integrity

  nano $LFS/sources/md5sums

In that file, enter the contents of http://www.linuxfromscratch.org/lfs/view/7.9/md5sums and then execute

  pushd $LFS/sources
  md5sum -c md5sums
  popd

Now, add a non-privileged user to prepare for building

  groupadd lfs
  useradd -s /bin/bash -g lfs -m -k /dev/null lfs
  passwd lfs
  chown -v lfs $LFS/tools
  chown -v lfs $LFS/sources
  su - lfs

Once you are logged in to the user, set up your bashrc and profile and re-establish the environment variables

  cat > ~/.bash_profile << "EOF"
  exec env -i HOME=$HOME TERM=$TERM PS1='\u:\w\$ ' /bin/bash
  EOF
 
And, make sure that the $LFS variable matches your mount point above, and not the default from the text

  cat > ~/.bashrc << "EOF"
  set +h
  umask 022
  LFS=/media/lfs
  LC_ALL=POSIX
  LFS_TGT=$(uname -m)-lfs-linux-gnu
  PATH=/tools/bin:/bin:/usr/bin
  export LFS LC_ALL LFS_TGT PATH
  EOF

Now, source both

  source ~/.bash_profile
  source ~/.bashrc

Once this is done, you are ready to start building the packages in $LFS/sources from source.  Make sure you are logged in as lfs, and env are set

  su - lfs
  echo $LFS

For building the packages from source ... the basics are as follows ...

  cd $LFS/sources
  tar xvf example.bz
  cd example
  make 
  make install clean
  cd ../
  rm example.bz

But, each package has special build instructions, so this is a point where we need to proceed slowly.  Starting with binutils:

  tar xvf binutils-2.26.tar.bz2
  mkdir -v build
  cd       build
  ../configure --prefix=/tools            \
               --with-sysroot=$LFS        \
               --with-lib-path=/tools/lib \
               --target=$LFS_TGT          \
               --disable-nls              \
               --disable-werror
  make
  case $(uname -m) in
    x86_64) mkdir -v /tools/lib && ln -sv lib /tools/lib64 ;;
  esac  
  make install
  cd ../../
  rm binutils-2.26.tar.bz2

Ok, so now you can see how despite the general rules for building from source, there will be significant variations for each package

 --- //[[jonathan@haacksnetworking.com|oemb1905]] 2019/12/30 02:37//