General Preparation

Clean any previous setup (user, group, directories etc..) and create the new setup.

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REMEMBER: This part is done via the root account of the host.

Exporting The 'LFS' Variable

This guide uses a target directory to build the new P-Linux ISO.

Having this variable set is beneficial in that commands such as mkdir -v $LFS/tools can be typed literally.

export LFS='/mnt/lfs'

Checking Architecture

uname -m

Which MUST return

x86_64

Clean Previous Setup

To compile everything from scratch it is best to remove any user, group and directories created by a previous run.

Removing User 'lfs' And Home-Directory

userdel --force --remove lfs

Options: userdel

• -f, --force: force removal of files, even if not owned by user
• -r, --remove: remove home directory and mail spool

Removing The Group 'lfs'

Normally, by removing the user, the group is removed as well. If not sure run the following command.

groupdel lfs

Removing Any Existing 'lfs' Target Directory

We first make sure $LFS/pkgmk is not mounted see: Optional Mounting A RAM Disk

umount -v $LFS/pkgmk
rm -rf $LFS

Removing Any Existing Related 'lfs' Links

rm -rf /tools
rm -rf /sources
rm -rf /pkgmk

Removing Previous 'lfs.swap' File

This could exist if you have execute the Optional Preparation part.

swapoff /lfs.swap
rm -rf /lfs.swap

Create A New Setup

Creating Folders & Links

Directory 'sources'

A list packages need to be downloaded in order to build a basic P-Linux system. Downloaded packages and patches will need to be stored somewhere that is conveniently available throughout the entire build.

Directory 'tools'

All programs compiled in the pass-1 will be installed under $LFS/tools to keep them separate from the programs compiled in the pass-2. The pass-1 compiles temporary tools and will not be a part of the final P-Linux system. Keeping them in a separate directorymakes it easier to removem them later.

Directory 'pkgmk'

This directory is used by the P-Linux Package Management Utilities p_cards to unback and compile the programs.

Links

The created symlinks enables the toolchain to be compiled so that it always refers to /tools (or the other links), meaning that all will be accessable in the pass-1 (when we are still using some tools from the host) and in the pass-2 (when we are “chrooted” to the new P-Linux folder).

The same goes for the other links.

To Create The Folders & Links

mkdir -vp $LFS/{sources,tools,pkgmk}
ln -svf $LFS/tools /
ln -svf $LFS/sources /
ln -svf $LFS/pkgmk /

Options: mkdir

• -p, --parents: no error if existing, make parent directories as needed

Creating 'lfs' Group & User

It is recommend to build the packages in pass-1 as an unprivileged user. To set up a clean working environment, we create a new user called lfs as a member of a new group (also named lfs). The password for this user is also set to lfs.

groupadd lfs
useradd -s /bin/bash -g lfs -m -k /dev/null lfs
echo "lfs:lfs" | chpasswd -m

Options: useradd

• -s, --shell SHELL: login shell of the new account

  In our case: -s /bin/bash This makes bash the default shell for user lfs.

• -g, --gid GROUP: name or ID of the primary group of the new account

  In our case: -g lfs This option adds user lfs to group lfs.

• -m, --create-home: create the user's home directory

• -k, --skel SKEL_DIR: use this alternative skeleton directory

  In our case: -k /dev/null This parameter prevents possible copying of files from a skeleton directory (default is /etc/skel) by changing the input location to the special null device.

• lfs: at the end is the actual name for the created user.

Options: chpasswd

• -m, --md5: encrypt the clear text password using the MD5 algorithm

  • the command is like this: echo "user_name:password_plaintext" | chpasswd -m

Setting Owner & Mode Of Folders

Grant user 'lfs' full access to $LFS and sub-directories by making lfs the directory owner:

Make the $LFS/sources directory writable and sticky. “Sticky” means that even if multiple users have write permission on a directory, only the owner of a file can delete the file within a sticky directory.

chown -v -R lfs $LFS
chmod -v a+wt $LFS/sources

Options: chpasswd

• -R, --recursive: operate on files and directories recursively

Creating 'lfs' User Files & Directories

Set up a good working environment by creating two new startup files for the lfs bash shell.

bash_profile

When logged on as user, the initial shell is usually a login shell which reads the /etc/profile of the host (probably containing some settings and environment variables) and then .bash_profile. The exec env -i.../bin/bash command in the .bash_profile file replaces the running shell with a new one with a completely empty environment, except for the HOME, TERM, and PS1 variables. This ensures that no unwanted environment variables from the host system leak into the build environment.

printf "%s\n" "exec env -i HOME=$HOME TERM=$TERM PS1='\u:\w\$ ' /bin/bash" > '/home/lfs/.bash_profile'

bashrc

The new instance of the shell is a non-login shell, which does not read the /etc/profile or .bash_profile files, but rather reads the .bashrc file instead.

printf "%s\n" "set +h" \
    "umask 022" \
    "LFS=/mnt/lfs" \
    "LC_ALL=POSIX" \
    "LFS_TGT=$(uname -m)-lfs-linux-gnu" \
    "PATH=/tools/bin:/bin:/usr/bin" \
    "export LFS LC_ALL LFS_TGT PATH" > '/home/lfs/.bashrc'

Creating user 'lfs log' Directory

mkdir -p /home/lfs/logs

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Automated Scripts

If you did not manually execute these steps, you can run the automated scripts from the root account of the host.

02_general_preparation.sh

See also Helper Scripts