LFS SystemD Build Scripts ========================= Shell scripts for building LFS SystemD Based upon https://www.linuxfromscratch.org/lfs/view/stable-systemd/ version 12.2 This git assumes the use user `lfs` has already been created according to the LFS book __except `$LFS=/mnt/newlfs` in these scripts__. This set of scripts does not use `fdisk` or `mke2fs`, those need to be run and formatted for the appropriate partitions before starting. With caution of course. See Chapter Two of the LFS book. The scripts associated with Chapter Nine and Ten in this git are *very* specific to my system and even then, currently not perfect (e.g. my network did not come up on first boot and there was a time zone issue). A future modification to these scripts may allow some of the hardware specific stuff (like filesystem `UUID`) to be set in a config file the scripts source but that has not yet been done. My build host is an is an `x86_64` LFS 11.3 (modified) system. There are some deviations from LFS 12.2, namely: * LibreSSL is used instead of OpenSSL *except* with Python3 * LTS Kernel series 6.6.x is being used in place of 6.10.x kernel series * Some versions are updated from what is in the LFS book. The host I currently am building from is an LFS 11.3 system with similar modifications. If curious, that LFS 11.3 system was built from a CentOS 7 host but some mods were needed to the CentOS 7 host and the LFS 11.3 build instructions for it to work (however I did then bootstrap build LFS 11.3 in LFS 11.3 without using the needed build instruction changes). The idea for this git was to first build LFS 12.2 to a thumb drive, and then boot the thumb drive to rebuild it to the hard disk. When LFS 12.2 is built on the USB Thumb Drive, it should then be possible to boot from the USB Thumb Drive and run the scripts again to build LFS 12.2 from LFS 12.2 on a hard disk partition where I can then proceed with the other steps in `THE_PLAN.md` towards creating a RPM distro from scratch. As of present (14 October 2024) the scripts build an LFS 12.2 SystemD system on my build host *except* the thumb drive does not boot and some of the initial configuration in Chapter Nine was not quite correct. See the file `INSTALL_NOTES.md` for details. Now that I have a working system, I am moving on to ‘Phase Two’ in `THE-PLAN.md` and am unlikely to make revisions to this git for some time. ------------------------- If you run the script `version-check.sh` (copy-pasta straight from the LFS book) and everything on your build system passes, there is a *good chance* these scripts can build LFS 12.2 on your build system. If anything on your build system does __not__ pass the tests in that scripts, there is a good chance your build system is not suitable. Sometimes you can upgrade some components, but it is smoother to start with a system already capable. Chapter 03 ‘Get Sources’ Script ------------------------------- This script is to be run by the `lfs` user. The partition LFS is to be built on must already be mounted at `/mnt/newlfs` and the directory `/mnt/newlfs/sources` should exist and be owned by the `lfs` user. The script will download the needed sources (sourcing `versions.sh`) and make a backup of the downloaded sources so that if run again, it can get the sources from the backup and not need to download them again. The file `versions.sh` also includes `sha256sum` digests so that the script can verify the integrity of the fetched files. Chapter 05 Building ------------------- In the `CH5Build` directory, the `lfs` user should execute the `Master.sh` script: lfs$ bash Master.sh The script works but is not finished. To do, it needs to verify the system is ready for the script to run. The `Master.sh` script calls the `CH05.*` scripts. Chapter 06 Building ------------------- In the `CH6Build` directory, the `lfs` user should execute the `Master.sh` script: lfs$ bash Master.sh The script works but is not finished. To do, it needs to verify the system is ready for the script to run. The `Master.sh` script calls the `CH06.*` scripts. Chapter 07 Building ------------------- __PAY ATTENTION__: First, the `root` user must execute the `CHROOT.sh` script: root# bash CHROOT.sh That script will copy `CH7Build`, `CH8Build`, `CH9Config`, and `KernelBuild` into `/mnt/newlfs/sources` so that those scripts will be available within the `chroot` and then fix some permissions and set up `/mnt/newlfs` for the `chroot` environment. Finally, it echoes the command that the `root` user must execute to enter the `chroot` environment. Once in the `chroot`: root# cd /sources/CH7Build root# bash 0-CH07-Prep.sh After executing `0-CH07-Prep.sh` reload `bash` with the following: root# exec /usr/bin/bash --login Then, still inside the `chroot` at `/sources/CH7Build`, execute: root# bash Master.sh Some important build tools previously built in the host environment will be rebuilt within the `chroot` environment. After the script runs, it will echo instructions on how to back things up. The backup takes a few minutes but it saves time when starting over if something goes wrong in Chapter 8 building. Chapter 08 Building ------------------- __PAY ATTENTION__: After running the build scripts for LFS Chapter 7, the instructions for creating the backup involved deleting the `/mnt/newlfs/sources` directory to reduse the size of the chroot tools backup. As the `lfs` user, re-run the `CH03-get-sources.sh` script to restore the sources: lfs$ bash CH03-get-sources.sh The script will restore the sources from the backup it made the first time it ran, it will not need to fetch them again. Then as the `root` user, once again execute the `CHROOT.sh` script to set up the `chroot` environment and copy the build scripts into it: root# bash CHROOT.sh Again, the script will echo the command to enter the `chroot`. Execute it as `root` and then once in the `chroot` environment: root# cd /sources/CH8Build root# bash Master.sh That will run many of the `CH08.*` scripts, building the LFS system through `CH08.34-bash`. Note that when it builds the `shadow` package, it first builds the `cracklib` package from BLFS and then links `shadow` against it. It does not however build PAM. PAM is a complex solution to complex problems that exist in enterprise. For the home user, those complex problems generally do not exist so the complex solution is not needed and using it is potentially dangerous as complex solutions that are not needed sometimes introduce remote exploitable code that otherwise would not exist. After it finishes building `bash`, the `Master.sh` script will instruct you to set the `root` password. After doing so, exit the `chroot` and re-enter so that the freshly rebuilt `bash` will be loaded. Reloading `bash` within the `chroot` *probably* would work too but since the binary the `chroot` command originally called has been replaced, just exit and re-enter. Once in the `chroot` environment again: root# cd /sources/CH8Build root# bash Master2.sh That will run the rest of the `CH08.*` scripts. Assuming all goes well, the system will be ready for LFS Chapter 9 configuration. It also builds several packages from BLFS, specifically enough so that a mouse, `wget`, `curl`, and the TLS certificate bundle (BLFS `make-ca`) are built, so that the new system will be capable of HTTPS connections. Note that `Master2.sh` does have a major deviation from the LFS book. It builds LibreSSL to provide the OpenSSL API (e.g. as used by the `kmod` package). Most software that builds against OpenSSL will build against LibreSSL and I have more trust in the LibreSSL developers. LibreSSL is also a smaller, more simpler code base. As of Python 3.10, Python 3 no longer allows building against LibreSSL. So OpenSSL is still built, the `_ssl` and `_hashlib` Python modules need it and are pretty important to a sane Python environment. See the file `TLS-README.md` for more information. After `Master2.sh` has successfully finished, exit the `chroot` and as root run the `PRENINE.sh`: root# bash PRENINE.sh Note that running that script is only needed when building the USB thumb drive that is used to run the scripts again. You can then enter re-enter the chroot (using the same command used before, it should be in very recent bash history) and proceed to the Chapter Nine configuration scripts. Chapter Nine Configuration -------------------------- These configuration scripts have things very specific to my hardware, such as the MAC Address of my NIC and the UUID identifiers for my disk partitions. ### Network Configuration For the network configuration, I am trying to use `systemd-networkd` to configure the network interface card, I think I understand the documentation for that and the general impression I get is that it works quite well. For DNS resolution however, I am *presently* disabling `systemd-resolved`. To understand why, see the file `SECURE_DNS.md`. Network configuration for the USB flash drive is to simply not use it, it does not need a network connection for anything, it will have all the source tarballs it needs to rebuild LFS on the target hard drive. ### /etc/fstab Note that for the generation of the `/etc/fstab` files, I am using the partion `UUID`. That is a deviation from the LFS book but it is a more reliable way to identify the partition to be mounted. For the `/etc/fstab` that will be used when built to the hard disk, the `/home` partition is commented out. My `/home` is actually shared between several different installs and distributions, so once I actually boot into the system and add the user accounts with their proper user and group ID, then I can uncomment that entry and reboot. For the `/etc/fstab` that will be used when built to the USB thumb drive, at boot it will mount the partition of the hard drive I plan to install to at `/mnt/newlfs` so that it is ready to go. There is an `fstab` entry for `/mnt/newlfs/boot` but it does not mount that filesystem automatically. That is also the `/boot` for my LFS 11.3 install and it will not be mounted until I am ready to build the kernel that will be installed to it, so the entry is there to make it easy to mount when I need to mount it but it will not actually be mounted until just before the kernel is compiled. The `/etc/fstab` entry for the root filesystem on the USB flash drive still needs to be filled in, I have not formatted the drive yet, I am still doing dry runs.