source: README@ e3ccc27

$Id$

1. INTRODUCTION::

     The scripts in this directory implement an automation of the building
  of a GNU/LInux system, as described in the Linux From Scratch book series.
  The name of the project is jhalfs: in that name, "alfs" stands for
  "automated linux from scratch", and the initials "jh" have been kept since
  the original "jhalfs-0.2" code developed by Jeremy Huntwork.

     The list of supported books can be found at
  http://wiki.linuxfromscratch.org/alfs/wiki/SupportedBooks.

     The documentation is split among various README.* files. Here is a list
  of what is in which:
    - README (this file): instructions to use the LFS book. This should be
      enough if you just want to build a base system as per the LFS book. It is
      also a required reading for all the other projects.
    - README.CLFS: supplementary instructions to use the CLFS book series.
    - README.BLFS: instructions to install an automated build infrastructure
      for the BLFS book. There are two ways to do so: (i) install the
      tools at the end of an LFS build (CLFS is not supported in that case), or
      (ii) install the tools on an already running system. Both methods are
      described in that file.
    - README.CUSTOM: instructions to run custom commands either during the xLFS
      build, at the end of a xLFS build. Note that you will not find
      instructions on how to write those commands, but some examples are
      available.
    - README.PACKAGE_MANAGEMENT: instructions to use package management during
      the build (only for LFS, patches welcome for CLFS...)
    - README.HLFS: very short file explaining why you cannot use HLFS with the
      present tool version.

     Other sources of information are the context help in the menu interface,
  and the xLFS books themselves.

2. PREREQUISITES::

     As said elsewhere, it is strongly advised that you first build manually
  a complete system before attempting to automate the build.

     Of course the "Host System Requirements" should be fulfilled. The needed
  supplementary packages are detailed at the bottom of the page:
  http://www.linuxfromscratch.org/alfs/download.html

3. INSTALLATION::

     No installation is required. You may want to move the files in this
  directory to a convenient location, and then follow the instructions below.

4. CONFIGURATION::

  4.1. CONFIGURATION OF THE TOOLS:
       There is no configuration of the tools themselves. The various
    parameters for the build are set through a menu driven interface. See
    the section RUNNING below for details.

  4.2. PRELIMINARY TASKS:
       This tool has no support at all for creating a partition and a mount
    point for the built system. You should follow the book up to the section
    "Mounting the new partition". Note that the default name for the
    partition mount point is "/mnt/build_dir", instead of /mnt/{c,}lfs.
    You can change that default to anything you'd like in the menu, so you
    may name it /mnt/lfs, or whatever you like. We'll use the name
    /mnt/build_dir in the sequel.

       The tool can download the needed packages for you, or you may download
    them yourself. The tool may optionally use a package archive directory
    where the downloaded packages are stored. That directory name may be made
    available to the tool in two ways: (i) export the SRC_ARCHIVE variable,
    for example SRC_ARCHIVE=/usr/src, (ii) enter the name at the "Package
    Archive Directory" menu prompt. Note that the user should have write
    permission to that directory. If a needed package is found in that
    directory, it is copied to /mnt/build_dir/sources, if not, it is
    downloaded to that directory and copied to /mnt/build_dir/sources,
    except if found in /mnt/build_dir/sources, in which case, it is just
    copied to $SRC_ARCHIVE. If you want the tool to download packages and you
    do not want to archive them, just unset SRC_ARCHIVE, and keep the
    default entry for "Package Archive Directory". If you choose to download
    the packages by yourself, you should download (or copy) them to
    /mnt/build_dir/sources directly.

       If you want to build the kernel as part of the automated build, select
    "Build the kernel" in the menu. Then, a configuration file must be
    provided. In order to do so, it is recommended to download the kernel
    tarball, unpack it, run <make menuconfig>, configure the kernel as per
    the book, and save the resulting .config file to a location where it can
    be retrieved later on (a convenient location and name is
    $SRC_ARCHIVE/config-<arch>-<kernel version>-<config details>).

       Another file you may provide is the fstab file. To use it, select
    "Use a custom fstab file" in the menu interface, and enter the name of
    the file where asked. As for the kernel configuration, this file has to
    be prepared before running the menu. A convenient location and name is
    $SRC_ARCHIVE/fstablfs.

       At a more advanced level, you may want to supply custom commands
    to be run at the end of (C)LFS build. Scripts containing those commands
    are located in the ./custom/config directory. Examples are given in
    ./custom/examples. A template is provided as ./custom/template. See
    README.CUSTOM for more details.

5. RUNNING::

  IMPORTANT::
      You must be logged as a normal user with sudo privileges to run
      the Makefile. Furthermore, you are supposed to have enough privilege
      to become any user. If you are not bothered about security issues,
      the entry for the user "jhalfs_user" in /etc/sudoers could be
      jhalfs_user ALL=(ALL) NOPASSWD:ALL

     The command <make> will launch a menu based configuration program. The
  underlying menu code was borrowed from BusyBox and slightly modified for
  our use.

     Help on parameter function is available from the on-line help. Please
  make use of that feature: it may contain additional information not
  duplicated in this file.

     You should first choose which book and flavour you want to build. Note
  that when you choose the BLFS book, the tool will just install the BLFS
  tool to your system. You'll have to run that installed tool to build
  packages in BLFS. See README.BLFS to know how. If you choose any other
  book, you'll have to configure the settings and the build parameters
  from the menu. Note that you may choose to install the blfs tools onto
  the newly built system. It is not the same thing as choosing
  the BLFS book in the menu, which will install the blfs tools on the
  currently running system.

     The "General Settings" menu is where the "Build Directory" name is to be
  entered. Other entries in that menu select what the tool should do. The
  "Run the Makefile" entry selects whether the tool will start the build
  automatically after generating the needed files. The "Rebuild files" selects
  whether to clean the build directory before doing anything else. To protect
  against removing important files, this can only be done in an empty directory,
  or a directory previously populated by the tool.

     The "Build Settings" menu is where various options for the build can be
  selected. Two options, "Use a custom fstab file" and "Build the kernel",
  have been described above. "Do not use/display progress_bar", if set, will
  prevent a progress bar to be displayed during the build. That may be useful
  on slow machine. The other options should be self explanatory, using either
  the online help or book reading.

     The "Advanced Features" menu is for various maintenance tasks, like
  testing the build instructions or reporting build statistics. One useful
  option is "Optimization and parallelisation". It is not recommended to use
  it for setting compiler optimization flags, although it is possible, but
  if you select it, you'll be able to select the number of parallel `make'
  jobs, which allows much faster builds on modern multicore CPUs.

     Once you have set the parameters and saved the configuration, the script
  is launched. Its aim is to extract instructions from the selected book
  to generate scripts, and to generate a Makefile, which allows running
  the scripts in the right order. The script verifies first that the host
  can run itself and build the xLFS system, then validates the configuration
  and lists the parameters. At this point, you may choose to quit or to
  continue with the listed parameters. The script will then proceed to
  generate the Makefile and the build scripts, optionally download
  packages, and eventually verify the host prerequisite. If you have
  selected "Run the makefile", the command <make> is launched in the
  adequate directory, and the build begins. If not, you'll have to run
  "make" manually, for example: "make -C /mnt/build_dir/jhalfs", if you
  have used the default parameters (see the layout under $BUILDDIR in the
  Q&A below).

  NOTE::
      If you run the jhalfs script directly the only function you can select
      is to display the version number by running <./jhalfs -v>

6. LAYOUT::

        /BLFS (see README.BLFS)

        /CLFS/master.sh
             /clfs.xsl

        /CLFS2/master.sh
              /clfs2.xsl

        /CLFS3/master.sh
              /clfs3.xsl

        /HLFS/master.sh
             /hlfs.xsl

        /LFS/master.sh
            /lfs.xsl

        /common/common_functions
               /makefile_functions
               /packages.xsl
               /urls.xsl
               /create-sbu_du-report.sh
               /progress_bar.sh
               /blfs-tool-deps/9xx-*
               /libs/func_*

        /custom/template
               /config/
               /examples/*
               /examples_CLFS-E/*

        /extras/do_copy_files
               /do_ica_prep
               /do_ica_work

        /optimize/opt_config
                 /opt_override
                 /optimize_functions
                 /opt_config.d/noOpt
                              /noSymbols
                              /O3pipe
                              /O3pipe_march
                              /defOpt_fPIC

        /menu/*

        README
        README.BLFS
        README.CLFS
        README.HLFS
        README.CUSTOM
        TODO
        LICENSE

        Config.in
        Makefile
        jhalfs
        blfs-tool

7. FAQ::
    Q. "It doesn't work"
    A. There are several reasons why it may be so. One possibility is the
       following: jhalfs was designed to work against the development versions
       of the LFS series of books. Consequently changes in a book sometimes
       break older versions of jhalfs. Before you start pulling out your hair,
       download the latest version of jhalfs to see if that solves your
       problem. Note that it may be the other way around. If you want to build
       an old version of the book, you may have to downgrade your jhalfs
       version.

    Q. "How do I specify the build location?"
    A. The original LFS document worked against the well known location
       /mnt/lfs. This script automates the build of all of the LFS series of
       books and uses a generic location $BUILDDIR with a default value of
       /mnt/build_dir. You may change this value to suit your needs.

       The layout below $BUILDDIR is as follows.
       $BUILDDIR/
            jhalfs      (Makefile, cmd scripts, logs, etc..)
            sources     (where packages reside)
            tools       (temporary bootstrap system)
            cross-tools (temporary CLFS only)
                ...
            FHS dir structure
                ...
            blfs_root   (files to use blfs-tool if selected to install it)

    Q. "What is the function of the SRC_ARCHIVE variable?"
    A. When jhalfs runs and packages download was selected, it creates a local
       copy of the necessary packages in $BUILDDIR/sources by downloading the
       files. If the variable SRC_ARCHIVE is defined the software will first
       look in this location for the file and, if found, will copy it to
       $BUILDDIR/sources.
       If the files are not found in SRC_ARCHIVE _and_ you have write priv to
       the directory any downloaded files will be mirrored there.

    Q. "How do I set the SRC_ARCHIVE location?"
    A. The best way to set the value of SRC_ARCHIVE is

       export SRC_ARCHIVE=/wherever/you/store/downloaded/packages

       or you can set the full path in the proper menu entry.

    Q. "Why have 2 copies of the files?"
    A. The package files must be visible during the chroot phase and this is a
       simple and reliable method of doing so. This method also handles the
       CLFS boot build method where the final build may be done on a separate
       machine.

    Q. "What is the function of "User account" and "Group account" menu
        settings?"
    A. If you are running jhalfs from a low or non-privileged account you may
       not have the priv to create/delete the user needed to build temporary
       tools.
       These settings allow you to use your own user and group name to do those
       build steps.

       These variables are adjustable also when invoking make:

         cd $BUILDDIR; make LUSER=myaccount LGROUP=mygroup

       The only changes to your account will be the creation of a NEW .bashrc
       after saving your original to .bashrc.XXX

    Q. "When I try to build CLFS the Makefile fails at mid-point"
    A. There could be numerous reasons for the failure but the most likely
       reason is you are doing a cross-build using the 'chroot' method and the
       target is not compatible with the host. If you choose to build using
       the chroot method a test is performed at the end of the temptools
       phase. If the test succeeds the build continues inside a chroot jail.
       However if the test fails, it means the host and target are not
       compatible an you should use the 'boot' method to create your target
       code.
       As an extreme example: You can build a sparc target on a x86 platform but
       only the temptools phase. You must select the 'boot' method and not the
       'chroot.' You must transfer the toolchain to a sparc platform, reboot the
       sparc box and continue the build.
       Of all the LFS series of books Cross-LFS requires the greatest
       understanding of host/target hardware combination. Please read the book
       carefully and don't skip the easy parts (there are none...)

    Q. "How could I stop the build at a predefined chosen point?"
    A. Launch the Makefile manually passing the last numbered target to be build
       as the break point. For example:

          make BREAKPOINT=84-bash

       The build can be stopped also at the end of a top-level build phase by
       calling directly the appropriate mk_* target. For example:

          make mk_LUSER

       See the Makefile to know the proper target names for that book build.

Authors:
  George Boudreau
  Manuel Canales Esparcia
  Pierre Labastie