Section 1
Our Goal
WHAT WE ARE BUILDING
This course walks through the creation of a 64-bit system based on the Linux kernel. Our goal is to produce a small, sleek system well-suited for hosting containers or being employed as a virtual machine.
Because we don't need every piece of functionality under the sun, we're not going to include every piece of software you might find in a typical distro. This distribution is intended to be minimal.
Here is what our end-result will look like:
- 64-bit Linux 4.8 Kernel with GCC 6.2 and glibc 2.24
- A system compatible with both EFI and BIOS hardware
- Bootable with GRUB2
- A VFAT formatted partition for GRUB/UEFI
- A boot partition
- A root partition
WHAT WE ARE LEARNING
This course provides step-by-step instructions in an effort to build the Linux kernel, the GNU C Standard Library implementation, GCC, and user-land binaries from source. The tasks are presented in linear order, and must be followed sequentially, as later tasks have dependencies on early tasks. Do not skip around.
Following this guide as intended will, in turn, enlighten you to many of the "hows" and "whys" of Linux, and assist in your ability to do tasks such as:
- Troubleshooting issues with the kernel
- Troubleshooting issues with user-land software
- Understanding the rationale behind various security systems and measures
- Performance tuning the kernel
- Performance tuning user-land binaries
- Building or "rolling" your own distribution
- Building user-land binaries from source
Required Skills and Knowledge
We make extensive use of VirtualBox in this course. Working knowledge of VirtualBox and a solid foundation in Linux and Linux troubleshooting are essential. If you're not as familiar with VirtualBox as you would like, take a look at the "How to Install CentOS 7 with VirtualBox" lesson in the "Linux Essentials Certification" course. That course, as well, provides the foundational knowledge required for this course.
Standards
As we progress through this course, we will adhere to the FHS (Filesystem Hierarchy Standard) specification, version 3.0. We will adhere (mostly) to the LSB (Linux Standard Base) specification, version 5.0. See the pertinent sections in this guide for more information on these two topics.
Filesystem Hierarchy Standard
We follow the FHS 3.0 specification in this course. The FHS provides guidance as to how the filesystem should be structured in terms of directory structure, partition location, and directory use.
FHS 3.0 specifies four major file categories:
- Static OR variable
- Shareable OR unshareable
It would seem there are two categories above; however, there are not. "Static" and "variable" represent two mutually-exclusive categories, as do "shareable" and "unshareable."
A file must fit into one of these four categories; that is, it must be static or variable, shareable or unsharable or some combination thereof. All files fall into two of the four categories, without exception.
The following directories are required in the primary (or root) hierarchy; their use is as noted.
bin:: Essential binariesboot:: Static boot-related filesdev:: Device filesetc:: Host-specific system configuration.lib:: Essential shared libraries and kernel modulesmedia:: Mount point for removable mediamnt:: Mount point for temporarily mounting a filesystemopt:: Add-on softwarerun:: Data relevant to running processes;/var/runis used more frequentlysbin:: Essential system binariessrv:: Data for services providedtmp:: Temporary filesusr:: Secondary hierarchy; identical to primary (root) hierarchyvar:: Variable (non-static) data
User home directories are located in
/usr/home, which is linked to /home. This standard also specifies in detail which binaries are required; more information regarding this may be found at http://refspecs.linuxfoundation.org/.Linux Standard Base
We follow the LSB Core Specification for the 64-bit x86 platform, as outlined at https://refspecs.linuxfoundation.org/LSB_5.0.0/LSB-Core-AMD64/LSB-Core-AMD64/book1.html.
The LSB standard is expansive, and outside of the scope of this course. Adherence and deviance from the standard will be pointed out in the course where we feel it is important to do so.
A Word on Linux
"Linux" as a term refers to two things: First, it refers specifically to the Linux kernel. Second, in a broader sense, it refers to the various packagings of the Linux kernel with other programs to provide the functionality required of a complete operating system.
Sound strange? It's not; it's one of the things that makes Linux so versatile. The kernel itself manages the hardware, memory, and the other parts of a computer system which are typically opaque to installed programs.
Programs installed to provide additional functionality are referred to as "user-land" or "the user-land." The combination of kernel and user-land constitute what are referred to as "distributions," many of which we are familiar: Red Hat Enterprise Linux, Ubuntu, Arch, Fedora, and so on.
In a broad sense, the term "Linux" refers to the operating systems created by the pairing of kernel and user-land, but the term is ambiguous. "Distribution," on the other hand, refers to the pairing of the kernel with a user-land built to some specification. Ubuntu, for instance, varies quite a bit from CentOS 6. Both of these are separate distributions of Linux.
Unlike operating systems, which are built in a monolithic fashion (where the user-land and kernel are tightly-coupled, such as FreeBSD, VMS, Windows, etc.), Linux allows for variations on theme which number into the thousands. The term "distro" better fits these variations, as each one is not entirely unique from the next (because of the shared kernel) but may differ substantially in terms of the user-land.
Section 2
Prerequisites: Build System Specifications
KERNEL/DISTRO VERSION
We use Fedora Core 24 in this course. You can run any distribution which uses a 4.x kernel, but be aware that doing so may introduce inconsistencies into the build process. Some distributions may package utilities using older or incompatible versions than what ia needed in this course.
CLEAN INSTALL
We strongly recommend that you use a clean install for the build system.
Notice we undertake the whole of this course in a virtual machine running in VirtualBox; we do this to facilitate the building of Linux in a clean environment.
Any virtualization environment will do, provided you have access to the console, as it may be necessary at various points. Actual hardware is also acceptable, if those resources are readily available to you.
BUILD SYSTEM DISK PARTITIONS
The build system — the virtual machine we use to build Linux — uses the following disk layout. This output is from the
parted print all command:Number Start End Size Type File system Flags
1 1049kB 525MB 524MB primary ext4 boot
2 525MB 19.3GB 18.8GB primary ext4
3 19.3GB 21.5GB 2147MB primary linux-swap(v1)
Whilst we walk through the creation of the destination drive (where our newly-built distribution will be installed) in the videos, you should have the proficiency to install Linux and the necessary tools prior to undertaking this course. It is strongly recommended that you take the "Linux Essentials" course on LinuxAcademy.com if your Linux skills are not quite at this level.
Development Tools
We'll need GCC, binutils, and other software packages installed with the "development tools" package group. You can select this during the installation process, or you can install using the
group install option for yum or dnf. Note that the package group names may differ depending on distribution, but generally, we will need the "development tools" and "C development tools" groups installed.LISTING PACKAGE GROUPS WITH DNF
dnf group list -v
LISTING PACKAGE GROUPS WITH YUM
yum grouplist hidden
INSTALLING PACKAGE GROUPS WITH DNF
dnf group install "C Development Tools and Libraries"
dnf group install "Development Tools"
INSTALLING PACKAGE GROUPS WITH YUM
yum groupinstall "Development Tools"
TEXINFO
You may also have to install the "tex info" package to obtain the "make info" binary:
dnf install texinfo
MS-DOS TOOLS
Our first partition needs to be formatted as FAT12 or FAT16 to enable interoperability with GRUB and EFI. For this reason, you need the "dosfstools" package, or similar, installed on your system.
Specific Software Packages and Required Versions
The
nano editor is used throughout this course; amend commands with your preferred text editor as needed.
Some of the software packages installed require a specific or minimum version. Most often, the most recent version (with patches) will be sufficient.
- bash (
/bin/shmust be a link to the bash binary) - binutils
- bison (
/usr/bin/yaccmust be linked to or provided by bison) - bzip2
- coreutils
- diffutils
- findutils
- gawk (
/usr/sbin/awkmust be a link to the gawk binary) - gcc 6.2
- glibc 2.24
- grep
- gzip
- Linux kernel 4.x
- m4
- make
- patch
- perl 5.24
- sed
- tar
- texinfo
- xz
YACC AND BISON
IMPORTANT
Note that Fedora Core 24 installs
byacc by default. This means yacc is not a link to the bison executable. You can verify this with the following command:rpm -qf `which yacc`
If the
yacc binary is installed by the byacc package, execute the following:
Remove the byacc package:
dnf erase byacc
Re-install bison
dnf reinstall bison
Link the bison binary:
ln -s `which bison` /bin/yacc
Call
yacc -V and make certain the output matches bison -V.HARDWARE/VIRTUAL HARDWARE SPECIFICATIONS
CPUs
Many of the packages we compile in this course can benefit from parallel make processes. The
make command can, in many cases, compile multiple source files simultaneously, provided the build system has more than one CPU.
It is strongly recommended than you allocate at least two CPUs if your build system is virtualized. If you are using hardware, ideally you will have at least two physical CPU cores to speed up the build process.
In particular, build and test times for software like GCC can be reduced a great deal by having
make execute processes in parallel. In places where you see -j2 indicated with the make command, it is perfectly acceptable to substitute a higher number, up to the number of CPUs allocated to the VM (or, if using hardware, the number of physical cores in the system). So, provided you have four CPU cores available, you are welcome to use -j4 instead of -j2.RAM
Virtualized or otherwise, you will need at least two gigabytes of free RAM available. Do not include swap space in this consideration. Builds may fail if swap use becomes extant.
Build System Disks
In addition to to the system disk, the build system needs an additional block storage device available. We recommend attaching a 20 gigabyte drive to the second port of the SAS or SATA controller of your virtual machine. If using hardware, this device can be a USB drive, a second hard, etc.; however, it must be a local block device physically attached to the system.
Users, Groups, and More
DON'T USE ROOT UNLESS NEEDED
The most important rule of this course parallels a general principle in *NIX in general: Do nothing as root unless it is required.
Particularly, when compiling code, it is very possible to crash your system or damage your installation. It is possible to even damage hardware in many cases. Beyond this, if you compile as root, you may find it next to impossible to work through the various steps of a process using anything but the root account. This sets us up for failure: Forget to set a single environment variable, and you've overwritten critical system libraries or binaries on the build system, only to find no binaries can be executed and the system cannot reboot.
At some stages of the build process, we must use the root account to execute commands. This will be noted when necessary.
Creating Our User
For this course, we create a user and group to execute our builds. Make sure the user is part of wheel group (or equivalent).
First, add our byol group:
groupadd byol
Be sure to add the
-k flag to the user add command to prevent files being copied to the home directory from /etc/skeleton:useradd -s /bin/bash -g byol -m -k /dev/null byol
We do this to prevent environment variables that might otherwise be appropriate for a user account from being set in our build environment, as these can have unintended consequences.
SETTING THE LOGIN ENVIRONMENT FOR THE BYOL USER
There should be two bash-related files in the home directory of the byol user:
.bash_profile and .bashrc.
The
.bash_profile file needs to have the following content:exec env -i HOME=$HOME TERM=$TERM PS1='\u:\w\$ ' /bin/bash
While the
.bashrc file needs to have the following content:set +h
umask 022
LC_ALL=POSIX
PATH=/tools/bin:/bin:/usr/bin
export LC_ALL PATH
These files are read during login, and set up the shell environment for the user. We set the environment here specifically to avoid inheriting environment variables that might have an adverse effect on our efforts.
After altering these files, upon log out and log in, the output from the
env command should return output similar to the following:TERM=xterm-256color
LC_ALL=POSIX
PATH=/tools/bin:/bin:/usr/bin
PWD=/home/byol
PS1=\u:\w\$
SHLVL=1
HOME=/home/byol
_=/bin/env
Destination Disk
Once you've configured your virtual machine, add an additional disk to it. 20 gigabytes should be sufficient; the disk type doesn't matter, but attaching to the SAS or SATA controller is recommended. We will refer to this newly attached disk as the "destination disk" from this point forward.
PARTITIONING THE DESTINATION DISK
By the conclusion of this section, the destination disk partition layout should look like this:
Number Start End Size File system Name Flags
1 1049kB 105MB 104MB fat16 primary bios_grub
2 105MB 551MB 446MB ext4 primary
3 551MB 19.3GB 18.7GB ext4 primary
4 19.3GB 21.5GB 2174MB linux-swap(v1) primary
The first partition begins at 1MB and extends to 104MB. This partition exists solely for the purposes of booting and is formatted as VFAT. We will refer to this partition as the EFI/GRUB boot partition henceforth.
The second partition begins at around 100MB and ends 400MB or so later. This is the boot partition.
The third partition begins at around 550MB and ends around 19GB. This is the root partition.
This last partition begins around 19MB and extends to the end of the disk. This is the swap parition.
The following command creates these partitions using
parted:parted --script /dev/sdb mklabel gpt mkpart primary 1MiB 100MiB mkpart primary 100MiB 525MiB mkpart primary 525MiB 19.3GB mkpart primary 19.3GB 100%
Setting Flags on the GRUB Boot Partition
The GRUB boot partition needs to have certain flags set so that BIOS-based systems can boot from it. We accomplish this using
parted:parted --script /dev/sdb set 1 bios_grub on
CREATING FILESYSTEMS ON THE DESTINATION DISK
Our partition table on our destination block storage device should look like this:
Number Start End Size File system Name Flags
1 1049kB 105MB 104MB fat16 primary bios_grub
2 105MB 551MB 446MB ext4 primary
3 551MB 19.3GB 18.7GB ext4 primary
4 19.3GB 21.5GB 2174MB linux-swap(v1) primary
Partition 1
mkfs.vfat /dev/sdb1
Partitions 2 and 3
The second and third partitions are our boot and root partitions. We will format these as "vanilla" ext4, using the
mkfs.ext4 command; note that your device name may be different:mkfs.ext4 /dev/sdb2
mkfs.ext4 /dev/sdb3
Partition 4
The last partition is our swap partition, which we will initialize using the
mkswap command:mkswap /dev/sdb4
SETTING PARTITION AND FILESYSTEM METADATA
We're going to set some volume metadata on our filesystems using the
tune2fs command.
Set the volume label of our second partition on our destination device to DESTBOOT:
tune2fs -c 1 -L DESTBOOT /dev/sdb2
Set the volume label of our third partition to DESTROOT:
tune2fs -c 1 -L DESTROOT /dev/sdb3
Note that we're setting the mount count to
1, which means the consistency of these filesystems will be checked after they have been mounted once. This is optional, but can be helpful in the event you have to reset your VM or build system and the filesystems aren't cleanly unmounted.SANITY CHECK
At this point, you should have:
- A complete build system with all of the necessary software installed to build Linux. Ideally, this system has two or more CPUs and two gigabytes or more of free RAM. Do not include available swap as free RAM.
- A byol user and group. This user should have access to root privileges via
suorsudo. - A second block storage device mounted on the build system, ideally on the same interface/controller as the system drive. This is our destination drive and should be partitioned and formatted as described above.
Measure twice, cut once: This is a good time to review all of the sections previous to this one and ensure your build system and destination disk are setup as recommended.
MOUNT POINT(S)
Destination Device: Root and Boot Directories
We're going to mount our destination disk on
/build, as follows, using the superuser account:mkdir -v /build
export BROOT=/build
mount -t ext4 -L DESTROOT $BROOT
mkdir -v $BROOT/boot
mount -t ext4 -L DESTBOOT $BROOT/boot
Adding Our Swap Partition
swapon -v /dev/sdb4
Exporting the BROOT Environment Variable
We're also going to add an export line to the
.bashrc file of the byol account to export the BROOT variable. Our .bashrc file should look like this:set +h
umask 022
LC_ALL=POSIX
PATH=/tools/bin:/bin:/usr/bin
BROOT=/build
export BROOT LC_ALL PATH
Sanity Check
Measure twice, cut once: you should have the root and boot destination filesystems mounted under
/build. Also, your swap partition should be active. We can check these with the mount and swapon commands:mount | grep 'sdb'
This should return a listing similar to:
/dev/sdb3 on /build type ext4 (rw,relatime,data=ordered)
/dev/sdb2 on /build/boot type ext4 (rw,relatime,data=ordered)
swapon | grep sdb should output similar:/dev/sdb4 partition 2G 0B -2
Keep in mind that your device names may be different.
Building the Toolchain
We're now ready to build the requisite toolchain needed to build Linux from scratch.
DIRECTORIES AND DIRECTORY PERMISSIONS
First, let's create a directory in our destination root to hold the source files:
mkdir -v $BROOT/source
We want the
/usr/src/toolchain directory to be sticky, which means that only the owner of a file can delete it. We also want the files in this directory to be writable for all users:chmod -v 777 $BROOT/source
Additionally, we want to create a directory to contain our compiled tools, which we need to keep aside and apart from the same binaries on the build system:
mkdir -v $BROOT/tools
We want to link this directory to the build system. The following command looks somewhat strange, but is correct:
ln -sv $BROOT/tools /
The result should be a symlink from
/tools in the build system root directory to the tools directory on the root of our destination device:ln -sv $BROOT/tools /
'/tools' -> '/build/tools'
SOURCE CODE FILES
A list of the software we need to install can be found at: http://linuxfromscratch.org/BROOT/view/stable/wget-list
We can download all of these files using two
wget commands:wget http://linuxfromscratch.org/BROOT/view/stable/wget-list
wget --input-file=wget-list --no-check-certificate --directory-prefix=$BROOT/source
We do not want the source code files located in our tools directory.
DECOMPRESS AND EXTRACT THE DOWNLOADED FILES
All of our source code files will have been compressed with
zx, bzip2, or gzip. We can decompress these files by running the following three commands:bunzip2 -d \*.bz2
gunzip \*.gz
xz -d \*.xz
CHANGE OWNERSHIP OF THE BUILD DIRECTORY
Execute:
chown -v byol:byol $BROOT
PATCH FILES
You'll notice that some of the files listed in the above TXT file are patch files. These patches need to be applied to the source before we compile the relevant package; we touch on this where necessary.
A WORD ON ERRORS
Both binutils and GCC must compile without errors. If either built has errors, start over. Depending on the error type you encounter this might mean rebuilding just GCC or rebuilding binutils as well.
Setting the Target Triplet
GCC and the rest of the build toolchain use a string called the "target triplet" to provide information as to the current CPU architecture, vendor, and operating system. The triplet itself is broken into three parts: machine-vender-os
So We could define our target triplet as follows:
x86_64-elf
However, we need to build GCC and the binutils toolchain without any external dependencies. To do that, our first build must be targeted for cross-compilation. This will ensure that all of the necessary dependencies are included and none of the shared libraries on the build system are relied upon. So we're going to use the triplet instead of the one above:
x86_64-BROOT-linux-gnu
This target triplet indicates an x86_64 compatible machine and an elf binary compatible operating system. Since we need this value set in our environment, let's add this to the
.bashrc file of the byol user. That file should now look like this:set +h
umask 022
LC_ALL=POSIX
PATH=/tools/bin:/bin:/usr/bin
BROOT=/build
BTARGET=x86_64-BROOT-linux-gnu
export BROOT BTARGET LC_ALL PATH
The vendor field is optional in the target triplet; we've specified "BROOT" here as this vendor code exists to facilitate building for purposes such as ours.
Target Triplets: What's the Point?
The purpose of the target triplet is to provide a means for the system and compilers to determine specific information about any given binary. After cross referencing and disambiguation, the target triplet is actually resolved to three distinct values, which may be quite different from the triplet specified above:
- Build Platform :: Where the binary was built.
- Host Platform :: Where the binaries are intended to run.
- Target Platform :: In the case of compilers, this is for what the compiler will generate code.
So after disambiguation, target triplets are "resolved" into something like this:
x86_64-elf-gcc
In fact, we could specify this value as our target triplet. This would result, however, in subtle changes in GCC's handling of code, and the outcome may not be desirable. For example, changing the vendor to the value
pc will result in the toolchain being cross-compiled with 32-bit compatibility enabled. This, in turn, will result in a different dynamic linker that will be used both at compile and runtime to line and find shared libraries, respectively. If GCC or glibc are configured incorrectly the result is often a toolchain that is broken such that problems do not manifest until the build process is nearly complete.Build Directory
For many of the builds, we
cd into the source directory and create a build directory. Once changed into this directory, we proceed with the build. This is the recommended way to build most of the toolchain, as it keeps the original source files from being tampered with by the build process.
If a build directory is not specified, it is not necessary and won't be used.
CONFIGURATION
Once in the build directory, the "configure" script is called from the parent directory to determine the options for the tool being built. This also copies the relevant source and configuration files from the original source directory to the build directory created in the previous section.
DELETING SOURCE DIRECTORIES
For some builds (like GCC and binutils), it is perfectly fine to delete only the
build directory after compilation and installation are executed. However, erring on the side of caution, it may be wise to delete the entire source directory to prevent misconfiguration down the road.Section 3
Stage 1: Building a Temporary Toolchain
The first stage of the build process entails building a toolchain capable of producing executables for our target platform. Because our target platform differs (in terms of the target triplet) from the platform on which we are building it (the build system), we need to first build a toolchain that is can be used in a "standalone" fashion. The ensures that we avoid any dependency on the build system environment or libraries.
Note that for Stage 1 builds, we don't execute the test suites for the software packages installed. The reason for this is simple — the dependencies required to run the tests, such as TCL, have not yet been installed, and the tests will likely fail.
Running the tests ceases to be optional once we reach Stage 3, however.
Compiling Binutils
CREATE THE BUILD DIRECTORY
Change into the binutils source directory under
$BROOT/source. Create a build directory:mkdir -v build && cd build
CONFIGURE THE SOURCE
Call the "configure" script from within the build directory to configure binutils. We used the following parameters for configure:
../configure \
--prefix=/tools \
--with-sysroot=$BROOT \
--with-lib-path=/tools/lib \
--target=$BTARGET \
--disable-nls \
--disable-werror
prefix:: Tells the configure script where the compiled binaries should be installed.with-sysroot:: Tells the configure script to look in the specified directory for the target system libraries.with-lib-path:: Specifies which path the linker will be configured to use.target:: Because the triplet we've defined is slightly different than what will be determined byconfigureitself, the binutils source needs to be compiled to accommodate cross-linking. This is necessary because we want to ensure a "clean room" build, without any artifacts from the build system.disable-els:: Disables internationalization, which we don't need at this stage.disable-werror:: Keeps warnings from interrupting the compile process.
COMPILE THE SOURCE
make -j2
CREATE A LIBRARY DIRECTORY AND SYMLINK
We need to create the
/tools/lib directory and symlink /tools/lib64 to it. This ensures that the proper libraries can be found along both paths:case $(uname -m) in
x86_64) mkdir -v /tools/lib && ln -sv lib /tools/lib64 ;;
esac
INSTALL BINUTILS
make install
DELETE THE BUILD DIRECTORY
Be sure to delete the
build directory once you've run make install.GCC
We are now going to build GCC. Because we're building GCC as a cross-compiler, it will not rely on libraries installed on the build system and instead prefers those packaged with it, or which we explicitly tell
configure to look for.OBTAIN THE GCC DEPENDENCIES
First, we need to download the GCC dependencies. We can do that using the following commands to copy the relevant software packages into the GCC source directory. Once they're copied,
make finds and builds these dependencies automatically. From the GCC source directory, execute:tar -xf ../mpfr-3.1.4.tar
mv -v mpfr-3.1.4 mpfr
tar -xf ../gmp-6.1.1.tar
mv -v gmp-6.1.1 gmp
tar -xf ../mpc-1.0.3.tar
mv -v mpc-1.0.3 mpc
Note that the software versions may have changed since this guide was written.
CHANGING THE DEFAULT LINKER
We need to instruct GCC to use the linker previously installed by our binutils install. The following script (which you should be able to copy and paste to a terminal window) finds the relevant header files and changes the locations where
make looks for certain libraries and files. Execute the following in the GCC source code directory:for file in \
$(find gcc/config -name linux64.h -o -name linux.h -o -name sysv4.h)
do
cp -uv $file{,.orig}
sed -e 's@/lib\(64\)\?\(32\)\?/ld@/tools&@g' \
-e 's@/usr@/tools@g' $file.orig > $file
echo '
#undef STANDARD_STARTFILE_PREFIX_1
#undef STANDARD_STARTFILE_PREFIX_2
#define STANDARD_STARTFILE_PREFIX_1 "/tools/lib/"
#define STANDARD_STARTFILE_PREFIX_2 ""' >> $file
touch $file.orig
done
Alternatively, you can save this code in a file in GCC source directory and run it by calling that file.
A more detailed description of what this script does, per the 'Linux From Scratch' online version:
"If case the above seems hard to follow, let's break it down a bit. First we find all the files under the GCC/config directory that are named eitherlinux.h,linux64.horsysv4.h. For each file found, we copy it to a file of the same name but with an added suffix of.orig. Then the firstsedexpression prepends/toolsto every instance of/lib/ld,/lib64/ld, or/lib32/ld, while the second one replaces hard-coded instances of/usr. Next, we add our define statements which alter the default startfile prefix to the end of the file. Note that the trailing/in/tools/lib/is required. Finally, we usetouchto update the timestamp on the copied files. When used in conjunction withcp -u, this prevents unexpected changes to the original files in case the commands are inadvertently run twice."
CONFIGURE
Create the build directory and change into it. Run the
configure script with the following arguments:../configure \
--target=$BTARGET \
--prefix=/tools \
--with-glibc-version=2.24 \
--with-sysroot=$BROOT \
--with-newlib \
--without-headers \
--with-local-prefix=/tools \
--with-native-system-header-dir=/tools/include \
--disable-nls \
--disable-shared \
--disable-multilib \
--disable-decimal-float \
--disable-threads \
--disable-libatomic \
--disable-libgomp \
--disable-libmpx \
--disable-libquadmath \
--disable-libssp \
--disable-libvtv \
--disable-libstdcxx \
--enable-languages=c,c++
target:: Tellsmaketo use the target triplet located in our environment variable.prefix:: Instructsmaketo use the specified path to prefix relative pathnames.ksswith-glibc-version:: Indicates which version of glibc we're going to target.with-sysroot:: Specifies the system root and allows us to specify a different root path than that of the currently-running kernel.with-newlib:: Prevents any code which requires libc from being compiled (because we haven't built libc yet).without-headers:: If building a full-blown cross-compiler, GCC needs the header files compatible with the target system. This argument instructsconfigureandmakenot to look for them, as we don't need them for this stage.with-local-prefix:: This instructsconfigureandmaketo search the specified directory for include files.with-native-system-header-dir:: This changes the default include path for headers (which is normally/usr/include) to/tools/include. Without this switch, GCC will look in the default location for include files, and that will break our build since our header files are located in/tools/include.disable-shared:: Advises GCC to avoid performing static linking. This is a good idea simply because it avoids any conflicts that might arise if GCC were built to use shared libraries, as the system linker might attempt to link them with the libraries installed on the build system.disable-decimal:: This GCC extension is not compatible when building GCC for cross compilation.disable-float:: Seedisable-decimal.disable-threads:: Seedisable-decimal.disable-libatomic:: Seedisable-decimal.disable-libgomp:: Seedisable-decimal.disable-libmpx:: Seedisable-decimal.disable-libquadmath:: Seedisable-decimal.disable-libssp:: Seedisable-decimal.disable-libvtv:: Seedisable-decimal.disable-libstdcxx:: Seedisable-decimal.disable-multilib:: This functionality isn't supported on the x86_64 platform.enable-languages:: For this stage, we need GCC to compile only C and C++. This disables the compilation of compilers for other languages.
MAKE GCC
make -j2
This will take some time.
INSTALL
make install
Do not delete the GCC source code directory just yet. Be sure to delete the
build directory, however.Install Kernel Header Files
The Linux kernel ships with a set of header files which provide programmers a software interface to the kernel. These are used primarily by libc (or the GNU implementation, glibc).
EXTRACTING THE KERNEL HEADER FILES
Change to the kernel source directory:
$BROOT/source/linux-4.x
Issue the following command:
make mrproper
We now call the
make command, specifying the header file output path; we do this in two steps because make wipes any files from the destination directory during this step. First, we extract the files:make INSTALL_HDR_PATH=dest headers_install
And second, we copy them to the proper location for libc:
cp -rv dest/include/* /tools/include
Building glibc
CONFIGURE
Run the
configure script with the following arguments. Note the exported variables; be sure to unset these when the build process is complete!
The
libc_cv_forced_unwind variable impacts the handling of the —force-unwind configuration parameter. The linker we installed when we compiled binutils is cross-compiled and cannot make use of the —force-unwind option unless glibc is present. This variable disables this test.
The
libc_cv_c_cleanup variables instruct configure to disable the test for this functionality, again for the same reasons given for libc\_cv\_forced\_unwind.
The commands for the configuration process should look like this:
export libc_cv_forced_unwind=yes
export libc_cv_c_cleanup=yes
../configure \
--prefix=/tools \
--host=$BTARGET \
--build=$(../scripts/config.guess) \
--enable-kernel=2.6.32 \
--with-headers=/tools/include
prefix:: Instructsmaketo use the specified path to prefix's relative pathnames.host:: Tellsmaketo use the target triplet located in our environment variable.build:: Combined with the host flag, this instructs glibc's build system to configure itself to cross compile, using the cross-linker and compiler in/tools.enable-kernel:: Instructs glibc to use workarounds for this specific version (and later) of the kernel.with-headers:: Specifies the location of header files, so libc knows what features the kernel has and can configure itself accordingly.
MAKE
According to the Linux From Scratch website, glibc sometimes breaks during parallel makes. We're going to disable parallel compilation for glibc by executing make as follows:
make -j1
make -j1 install
DELETE THE BUILD DIRECTORY
Be sure to delete the
build directory once you've run make install. Additionally, unset the environment variables defined during our configuration:unset libc_cv_forced_unwind
unset libc_cv_c_cleanup
Sanity Check
At this point, it is imperative that we stop and check our temporary toolchain to ensure that it has been built correctly. The online version of the "Linux From Scratch" website provides us a neat and sure method of testing that our toolchain is installed correctly.
TESTING THE TOOLCHAIN
We can test the temporary toolchain to check it compiles and links code and object code correctly with the following commands:
echo 'int main(){}' > dummy.c
$BTARGET-gcc dummy.c
readelf -l a.out | grep ': /tools'
Note that this should be done as the byol user.
If everything is working as it should be, the
grep command should return this output:[Requesting program interpreter: /tools/lib64/ld-linux-x86-64.so.2]
If the output is different — particularly if the program interpreter is located on the build system's filesystem hierarchy (
lib/ld-linux-x86-64.so.2, etc.) - then something has gone wrong.
Delete the build directories, check environment variables and start over. Continuing will result in a toolchain that is broken in odd ways which are not immediately apparent.
Be sure to delete all of the
dummy.* files when you're done testing.Building libstdc++
LIBSTDC++ IS PART OF GCC
This software is part of the GCC sources, so we'll need to be in the
gcc source directory, in an empty build directory, before executing the following.CONFIGURE
Create the
build directory as per usual, and run the configure script with the following arguments:../libstdc++-v3/configure \ --host=$BTARGET \ --prefix=/tools \ --disable-multilib \ --disable-nls \ --disable-libstdcxx-threads \ --disable-libstdcxx-pch \ --with-gxx-include-dir=/tools/$BTARGET/include/c++/6.2.0
MAKE
make -j2
make installSection 4
Stage 2: Building with The Temporary Toolchain
At this point, we've created a temporary toolchain capable of compiling and linking executables in a stand-alone sense. Now we need to make an additional compilation pass over these same tools so they are native to our target triplet.
In a sense, Stage 2 creates a "temporary" system, using minimal installations of several familiar programs and libraries like ncurses, bash, and more.
Compiling Binutils - Native Build
CREATE THE BUILD DIRECTORY
Change into the binutils source directory under
$BROOT/source. Create a build directory:mkdir -v build && cd build
CONFIGURE THE SOURCE
Because we want a native build of binutils, call the target-triplet-specific utilities installed in our first build of binutils:
export CC=$BTARGET-gcc
export AR=$BTARGET-ar
export RANLIB=$BTARGET-ranlib
Call the "configure" script from within the build directory to configure binutils. We used the following parameters for configure:
../configure \
--prefix=/tools \
--disable-nls \
--disable-werror \
--with-lib-path=/tools/lib \
--with-sysroot
with-sysroot:: Specifying no value here enables the linker to find shared libraries required by other objects. Without this flag,makemay not be able to locate and link some required libraries.with-lib-path:: Here we're instructingmaketo use the specified directory explicitly.
COMPILE THE SOURCE
make -j2
INSTALL BINUTILS
make install
PREPARE THE LINKER FOR UPCOMING ADJUSTMENTS
The following commands clean out the build directory for the
ld utility, and then rebuilds the same. We specify the LIB_PATH to override the default value used by the temporary toolchain — this is the default library search path.make -C ld clean
make -C ld LIB_PATH=/usr/lib:/lib
cp -v ld/ld-new /tools/bin
Building GCC Natively
REPLACING THE INTERNAL GCC LIMITS.H HEADER
GCC initially uses a self-provided
limits.h file for the building of the temporary toolchain. Now, we want GCC to use a full set of definitions written in the limits headers. To ensure this, we concatenate several of GCC's internal files to create a single limits.h file:cat gcc/limitx.h gcc/glimits.h gcc/limity.h > dirname $($BTARGET-gcc -print-libgcc-file-name)/include-fixed/limits.h
CHANGING THE DEFAULT LINKER (AGAIN)
Once again, we want GCC to use the linker installed in our
/tools directory:for file in \
$(find gcc/config -name linux64.h -o -name linux.h -o -name sysv4.h)
do
cp -uv $file{,.orig}
sed -e 's@/lib\(64\)\?\(32\)\?/ld@/tools&@g' \
-e 's@/usr@/tools@g' $file.orig > $file
echo '
undef STANDARD_STARTFILE_PREFIX_1
undef STANDARD_STARTFILE_PREFIX_2
define STANDARD_STARTFILE_PREFIX_1 "/tools/lib/"
define STANDARD_STARTFILE_PREFIX_2 ""' >> $file
touch $file.orig
done
GCC DEPENDENCIES
These should already be in place, as this step was required for the Stage 1 build of GCC. However, if for some reason you've deleted the GCC source directory, re-trace the steps for installing the GCC dependencies as described previously.
CONFIGURE
Create the build directory and change into it. As with the build of binutils in the previous section, we define some environment variables before compiling:
export CC=$BTARGET-gcc \
export CXX=$BTARGET-g++ \
export AR=$BTARGET-ar \
export RANLIB=$BTARGET-ranlib \
Run the
configure script with the following arguments:../configure \
--prefix=/tools \
--with-local-prefix=/tools \
--with-native-system-header-dir=/tools/include \
--enable-languages=c,c++ \
--disable-libstdcxx-pch \
--disable-multilib \
--disable-bootstrap \
--disable-libgomp
BUILD GCC
Execute:
make -j2
make install
CREATE THE CC SYMLINK
Typically, scripts call
cc instead cf gcc or clang to compile code. This allows developers to use different compilers without having to re-edit scripts or write scripts for each compile. The behavior is accomplished by creating a symlink to the compiler executable; in our case, cc should be a link to the gcc binary:ln -sv gcc /tools/bin/cc
CLEANUP
Be sure to unset the exported variables above. You may also logout and log back in as the byol user to reset the environment.
Sanity Check
Once again, we need to stop and double-check our toolchain to make sure that it can compile and link executables properly.
Execute the following commands:
echo 'int main(){}' > dummy.c
$BTARGET-gcc dummy.c
readelf -l a.out | grep ': /tools'
Note that this should be done as the byol user.
If everything is working as it should be, the
grep command should return this output:[Requesting program interpreter: /tools/lib64/ld-linux-x86-64.so.2]
If the output is different — particularly if the program interpreter is located on the build system's filesystem hierarchy (
lib/ld-linux-x86-64.so.2, etc.), then something has gone wrong.
Return to the last sanity check and re-trace your steps. Continuing will result in a broken toolchain that will likely not compile or link correctly.
Test Suite Dependencies
The test suite used for our toolchain requires a handful of dependencies. During the first and second compilation passes of binutils GCC, and Glibc, we didn't allow
make to execute tests — as the necessary programs were missing, there was no point in doing so.
At this stage, however, we most certainly do want to run the tests to make sure our toolchain is set up properly.
We downloaded the source code for the programs used in testing during Stage 1. Now we need to compile and install them. Unless it is otherwise noted, you'll need to extract the source code directories from the appropriate tar file in
/sources, cd into it and execute the configure and make commands. It is assumed from this point forward that you have extracted the source and are in the resulting directory. Note that most of these utilities do not require the use or creation of a separate 'build' directory.REGARDING MAKE AND MAKE INSTALL
These commands can typically run one after another.
make && make install
Sometimes, however, there is good reason to separate the commands into two steps, such as when header files or libraries need to be modified before being installed. Where you see the two commands one after another (as in the following example):
make
make install
You can replace the two commands with a single line:
make && make install
Be careful, though, to use this only where the
make and make install commands are one after the other, and no additional steps are required.TCL
Configure:
cd unix
./configure --prefix=/tools
Compile:
make -j2
Install:
make install
Change Permissions
chmod the installed library file so we can strip out debugging symbols later:chmod -v u+w /tools/lib/libtcl8.6.so
Install Headers
make install-private-headers
Create Required Symlink
Be sure to replace the
xxx with the appropriate minor version of TCL in the following command:ln -sv tclsh8.xxx /tools/bin/tclsh
EXPECT
First, we want to force
expect to use /bin/stty to open a terminal as opposed to /usr/local/bin/stty; the binary in /usr/local is located on the build system (as we don't have a /usr/local hierarchy on our destination disk). We don't want expect to depend on that binary.
To remedy this, execute:
cp -v configure{,.orig}
sed 's:/usr/local/bin:/bin:' configure.orig > configure
This uses
sed to replace the path used by the configure script.Configure
./configure --prefix=/tools --with-tcl=/tools/lib --with-tclinclude=/tools/include
Install
We include the
SCRIPTS variable so make will skip including supplemental scripts.make SCRIPTS="" install
DEJAGNU
Configure
./configure --prefix=/tools
Compile and Install
make install
CHECK
Configure
We include an empty
PKG_CONFIG variable here to prevent any pre-defined pkg-config options that may lead make to link against libraries on the build system.PKG_CONFIG= ./configure --prefix=/tools
Compile and Install
make
make install
NCURSES
Ncurses is a library which provides terminal control routines. It allows for a basic graphical user interface to be used in text-only (e.g., terminal or console) environments.
Configure
We amend the source code here to ensure that the
gawk command is found before awk:sed -i s/mawk// configure
./configure --prefix=/tools \
--with-shared \
--without-debug \
--without-ada \
--enable-widec \
--enable-overwrite
Compile and Install
make
make install
BASH
Configure
./configure --prefix=/tools --without-bash-malloc
We pass the
—without-bash-malloc parameter to disable bash's internal malloc(), which is known to be somewhat buggy.Compile and Install
make
make install
Symlink sh
In many distributions, the
sh command is actually a symlink to the bash executable; ours is no different. Create the symlink with the following command:ln -sv bash /tools/bin/sh
BZIP
The
bzip package does not use a configure script, only make.Compile
make
Install
We pass the
PREFIX variable here to ensure the resulting binaries are installed in the /tools hierarchy.make PREFIX=/tools install
COREUTILS
The
coreutils package provides many of the basic user-land utilities we use in the shell to manipulate text, files and the environment.Configure
Notice the
--enable-install-program parameter. We pass this to configure to build the 'hostname' program, which is disabled by default../configure --prefix=/tools --enable-install-program=hostname
Compile and Install
make
make install
DIFFUTILS, FILE, FINDUTILS, AND GAWK
These software packages use identical configuration and compilation/install steps. Execute these steps for each of these packages — be sure not to skip any.
Configure
./configure --prefix=/tools
Compile and Install
make
make install
GETTEXT
We only need three programs from the
gettext package at this point: msgfmt, msgmerge and xgettext; hence the unusual make commands.Configure
Note that we pass an empty "EMACS" variable to
configure; this prevents the detection of Lisp scripts used by emacs, which is known to hang some systems. Be certain to cd into the gettext-tools directory before running configure.cd gettext-tools
EMACS="no" ./configure --prefix=/tools --disable-shared
Compile the Binaries
make -C gnulib-lib
make -C intl pluralx.c
make -C src msgfmt
make -C src msgmerge
make -C src xgettext
Install
Rather than using
make to install our binaries for us, we copy them into place manually:cp -v src/{msgfmt,msgmerge,xgettext} /tools/bin
GREP, GZIP, AND M4
These software packages use identical configuration and compilation/install steps. Execute these steps for each of these packages — be sure not to skip any.
Configure
./configure --prefix=/tools
Compile and Install
make
make install
MAKE
Configure
Here we pass the
—without-guile flag to configure. While these libraries may be available on the build system, they are not on our destination, and we don't want make to depend on them for that reason../configure --prefix=/tools --without-guile
Compile and Install
make
make install
PATCH
Configure
./configure --prefix=/tools
Compile and Install
make
make install
PERL 5
Configure
The Perl source code doesn't use the standard
configure script. Note the capital C in the configuration command:sh Configure -des -Dprefix=/tools -Dlibs=-lm
Compile
make
Install
We only need a few of the libraries we've built, so we'll copy these to our destination manually:
cp -v perl cpan/podlators/scripts/pod2man /tools/bin
mkdir -pv /tools/lib/perl5/5.24.0
cp -Rv lib/* /tools/lib/perl5/5.24.0
SED, TAR, AND TEXINFO
Configure
./configure --prefix=/tools
Compile and Install
make
make install
UTIL-LINUX
Configure
We include an empty
PKG_CONFIG variable here to prevent any pre-defined pkg-config options that may lead make to link against libraries on the build system../configure --prefix=/tools \
--without-python \
--disable-makeinstall-chown \
--without-systemdsystemunitdir \
PKG_CONFIG=""
without-python:: This disables the Python bindings, which we don't need at this point.disable-makeinstall-chown::maketries to change the owner of the binaries after copying them into place. This requires root permissions, however, so we disable this.without-systemdsystemunitdir:: This instructsmaketo skip the installation of systemd-specific files.
Compile and Install
make
make install
XZ
Configure
./configure --prefix=/tools
Compile and Install
make
make install
Stripping (Optional)
Now that we've got a temporary system built and installed, we can save some space by removing the debug symbols from our binaries and our libraries.
This command will result in quit a "File format not recognized" warning messages. This is normal — if you examine the file indicated in the message, you can note that the file in question is usually a script file, not a binary.
Please be very careful with this step. It is very easy to strip the wrong files and delete most of the libraries we've just built and installed.
THIS STEP IS OPTIONAL.
STRIP THE DEBUG SYMBOLS FROM OUR LIBRARIES
strip --strip-debug /tools/lib/*
STRIP THE DEBUG SYMBOLS FROM OUR BINARIES
DO NOT run this command against library files! This command uses the build system's strip binary to remove unneeded symbols. Running this against library files deletes them.
/usr/bin/strip --strip-unneeded /tools/{,s}bin/*
Switching to Root
At this point, we've used the byol user for almost every activity, save the creation and mounting of our destination file system.
From this point forward, however, we will undertake all commands as root.
ENVIRONMENT CHECK
Execute
su and run:env | grep ^B
Your output should look something like this:
BROOT=/build
BTARGET=x86_64-BROOT-linux-gnu
While the "BROOT" environment variable is required, the "BTARGET" variable is not, and must not be set as we continue forward.
UNSETTING THE BTARGET ENVIRONMENT VARIABLE
Unset this variable with the following command:
unset BTARGET
Check again to make sure that the variable has been unset:
env | grep ^B
"BTARGET" should not be anywhere in the output.
SETTING THE BROOT ENVIRONMENT VARIABLES
If you're missing "BROOT", you can set it easily enough:
export BROOT="/build"
Changing File Ownership
Now that we've installed our binaries and libraries, we need to change their ownership.
We've built and installed our binaries and libraries using the byol user so far. Our destination system, however, does not have any users defined. This poses a minor security risk — a user could be created with a user ID identical to that of the byol user on the build system, which would then have access to all our binaries.
The simplest way to restrict access is to make root the owner of these files, as the superuser ID is identical across all systems:
chown -R root:root $BROOT/tools
If we examine these files, we should see that both user and group are set to root:
root:~# ls -la $BROOT/tools
total 68
drwxr-xr-x 13 root root 4096 Nov 30 18:20 .
drwxr-xr-x 7 byol byol 4096 Nov 29 00:57 ..
drwxr-xr-x 2 root root 12288 Nov 30 19:31 bin
drwxr-xr-x 2 root root 4096 Nov 30 17:25 etc
drwxr-xr-x 40 root root 4096 Nov 30 19:26 include
drwxr-xr-x 11 root root 12288 Nov 30 19:30 lib
lrwxrwxrwx 1 root root 3 Nov 30 17:00 lib64 -> lib
drwxr-xr-x 6 root root 4096 Nov 30 19:16 libexec
drwxr-xr-x 5 root root 4096 Nov 30 18:20 man
drwxr-xr-x 2 root root 4096 Nov 30 19:31 sbin
drwxr-xr-x 16 root root 4096 Nov 30 19:25 share
drwxr-xr-x 3 root root 4096 Nov 30 17:25 var
drwxr-xr-x 5 root root 4096 Nov 30 17:29 x86_64-BROOT-linux-gnu
drwxr-xr-x 4 root root 4096 Nov 30 17:50 x86_64-pc-linux-gnu
Backing Up
Now that we've got a complete (albeit temporary) system, it would be wise to backup our work. If you're using a virtual machine, exporting the VM as an OVA file is one way of ensuring you've got a patent backup.
You may choose to
tar the /build directory — whatever works. The point is that you'll be able to restore the environment to the state it is in now with minimal effort at some point in the future.
This is important, particularly as a time-saver: Everything we do from this point will alter the binaries and libraries we've built and installed, so there is a possibility things will break irreparably.
BE SURE TO DOUBLE CHECK YOUR ENVIRONMENT AS PER "Switching to Root" BEFORE CONTINUING.
Section 5
Stage 3: Native (Full) System Build
Up to this point, we've used the byol user to build and install software, with a few notable exceptions. Be sure to check your environment as noted in "Switching to Root" in the previous section.
From this point forward, everything we do will be as the root user. After creating our virtual and pseudo filesystems, we'll make use of the
chroot command to set up a working environment for our destination system.
To protect our build system, and to enable the use of virtual and pseudo filesystems on our destination, we undertake much of the Stage 3 process in a 'chroot jail.'
A NOTE REGARDING PACKAGE BUILDS
After the nal GCC compile pass, it is necessary to compile software packages using fresh source les. This is to prevent any previous con guration from breaking the build. We strongly recommend you re-extract source code from the appropriate tar le before building and installing any of the userland binaries.
The packages are compiled and installed in the order given to ensure that all dependencies are met. They must, therefore, be installed in the order speci ed.
Required Directories and Devices
DIRECTORIES
We need to create some directories before mounting filesystems:
mkdir -pv $BROOT/{dev,proc,sys,run}
The output from this command should look like this:
mkdir: created directory '/build/dev'
mkdir: created directory '/build/proc'
mkdir: created directory '/build/sys'
mkdir: created directory '/build/run'
DEVICE NODES
In addition to the directories required for a fully-functioning system, we need to create some device nodes. These are expected to exist by the kernel and many programs. Execute:
mknod -m 600 $BROOT/dev/console c 5 1
mknod -m 666 $BROOT/dev/null c 1 3
Mounting Device, Pseudo, and Virtual Filesystems
The kernel and many user-land programs expect these filesystems to be mounted;
vmstat is one such example.MOUNTING THE DEV FILESYSTEM
To populate the
dev filesystem, we first need to mount it. We do so by using a "bind" mount, which mounts $BROOT/dev on to the /dev mount of our build system. The result is that $BROOT/dev and /dev will be mounted to the same node, and display the same information.
Normally, the
dev filesystem would be populated by dev at boot. However, since we haven't installed the udev package, and since we haven't booted our destination system, we need to populate this filesystem manually.
Execute the following to bind
$BROOT/dev to /dev:mount -v --bind /dev $BROOT/dev
MOUNTING OTHER PSEUDO AND VIRTUAL FILESYSTEMS
The
gid parameter below ensures that the mount is owned by the group whose ID is 5; we later assign this ID to the 'tty' group when we create our /etc/groups file. The 'mode' parameter sets the file mode (permissions) for the device in question.mount -vt devpts devpts $BROOT/dev/pts -o gid=5,mode=620
mount -vt proc proc $BROOT/proc
mount -vt sysfs sysfs $BROOT/sys
mount -vt tmpfs tmpfs $BROOT/run
THE SPECIAL CASE OF DEV/SHM
Some distributions link
/dev/shm to /run/shm. Since we've created the "run" filesystem above, we only need to create the directory:if [ -h $BROOT/dev/shm ]; then
mkdir -pv $BROOT/$(readlink $BROOT/dev/shm)
fi
Entering the chroot jail
We're now ready to enter the jail and continue the final build of our distribution.
IF YOU REBOOT, YOU MUST RE-POPULATE
/dev AND RE-MOUNT THE PSEUDO/VIRTUAL FILESYSTEMS AS NOTED IN THE PREVIOUS SECTION.CAVEATS
The jail provides limited functionality — we've only installed the most basic of tools. At this stage, the goals are to simulate a running destination system and protect the build system from damage. This is why environment variables and filesystem mounts are so important.
ENTERING THE JAIL
You must be logged in as the superuser to execute the
chroot command. Note that we specify the $BROOT for bash, which will adopt this location as the root directory of the jail. The "HOME", "TERM", "PATH" and prompt environment variables are passed in to set up our environment inside the jail. Other parameters are explained below:chroot "$BROOT" /tools/bin/env -i HOME=/root TERM="$TERM" PS1='\u:\w\$ ' PATH=/bin:/usr/bin:/sbin:/usr/sbin:/tools/bin /tools/bin/bash --login +h
-i:: Instructsenvto clear all environment variables upon entering the jail.--login:: Notifies bash to provide an interactive login.+h:: Disables path-having by bash. This is important; note that the/tools/bindirectory (where we've installed many of our binaries) is last on the path. This means that the tools we install at this stage will be found before tools installed at previous stages, which is the desired behavior.
Your output from this command should be something like:
I have no name!:/#
Directory Structure
We now need to create the basic directory structure inside our jail, in keeping with the FHS standard.
CREATING DIRECTORIES
mkdir -pv /{bin,boot,etc/{opt,sysconfig},home,lib/firmware,mnt,opt}
mkdir -pv /{media/{floppy,cdrom},sbin,srv,var}
install -dv -m 0750 /root
install -dv -m 1777 /tmp /var/tmp
mkdir -pv /usr/{,local/}{bin,include,lib,sbin,src}
mkdir -pv /usr/{,local/}share/{color,dict,doc,info,locale,man}
mkdir -v /usr/{,local/}share/{misc,terminfo,zoneinfo}
mkdir -v /usr/libexec
mkdir -pv /usr/{,local/}share/man/man{1..8}
case $(uname -m) in
x86_64) ln -sv lib /lib64
ln -sv lib /usr/lib64
ln -sv lib /usr/local/lib64 ;;
esac
mkdir -v /var/{log,mail,spool}
ln -sv /run /var/run
ln -sv /run/lock /var/lock
mkdir -pv /var/{opt,cache,lib/{color,misc,locate},local}
Take special note of the permissions assigned to the root home directory and the temporary directories.
Required Files
Some user-land programs require the existence of specific files before they can be installed or used. We create these files (or links) here. These will be replaced as we build and install the user-land.
CREATING FILES AND LINKS
Execute the following:
ln -sv /tools/bin/{bash,cat,echo,pwd,stty} /bin
ln -sv /tools/bin/perl /usr/bin
ln -sv /tools/lib/libgcc_s.so{,.1} /usr/lib
ln -sv /tools/lib/libstdc++.so{,.6} /usr/lib
sed 's/tools/usr/' /tools/lib/libstdc++.la > /usr/lib/libstdc++.la
ln -sv bash /bin/sh
The purpose of each is explained below:
/bin/bash:: Quite a few scripts expect the bash binary to be located here. Creating this symlink keeps those scripts from breaking./bin/cat:: Glibc hard-codes this pathname into itsconfigurescript./bin/echo:: Used by Glibc's test-suite; this path is also hard-coded./bin/pwd:: Used by Glibc; this path is hard-coded./bin/stty:: This pathname is hard-coded by theexpectpackage./usr/bin/perl:: Many scripts expect to find the PERL binary at this location; this keeps them from breaking./usr/lib/libgcc\_s.so{,.1}:: This is need by Glibc to enable POSIX threads./usr/lib/libstdc++{,.6}:: Needed for C++ support by GMP and Glibc's test suite./usr/lib/libstdc++.la:: This prevents GCC from referencing a previously built library of the same name in ourtoolsdirectory./bin/sh:: Some scripts hard-code this binary path.
MTAB
The kernel historically exposes the list of mounted filesystems via the
/etc/mtab file. Some user-land binaries expect this information available. To do this, execute:ln -sv /proc/self/mounts /etc/mtab
/ETC/PASSWD
The need for this file is obvious, without it, we can't set passwords or log in to our system once we boot it.
cat > /etc/passwd << "EOF"
root:x:0:0:root:/root:/bin/bash
bin:x:1:1:bin:/dev/null:/bin/false
daemon:x:6:6:Daemon User:/dev/null:/bin/false
messagebus:x:18:18:D-Bus Message Daemon User:/var/run/dbus:/bin/false
nobody:x:99:99:Unprivileged User:/dev/null:/bin/false
EOF
/ETC/GROUP
This is another file we need to make use of file permissions properly.
cat > /etc/group << "EOF"
root:x:0:
bin:x:1:daemon
sys:x:2:
kmem:x:3:
tape:x:4:
tty:x:5:
daemon:x:6:
floppy:x:7:
disk:x:8:
lp:x:9:
dialout:x:10:
audio:x:11:
video:x:12:
utmp:x:13:
usb:x:14:
cdrom:x:15:
adm:x:16:
messagebus:x:18:
systemd-journal:x:23:
input:x:24:
mail:x:34:
nogroup:x:99:
users:x:999:
EOF
RE-EXECUTING OUR LOGIN SHELL
The following command instructs bash to execute another login. This results in our bash prompt changing, as we've now installed the
etc/passwd and /etc/group files.exec /tools/bin/bash --login +h
Your login prompt should now reflect the user root.
MANDATORY LOG FILES
We need to populate
/var/log with files that are expected by a number of user-land utilities.touch /var/log/{btmp,lastlog,faillog,wtmp}
chgrp -v utmp /var/log/lastlog
chmod -v 664 /var/log/lastlog
chmod -v 600 /var/log/btmp
Installing the Kernel Headers (Again)
Just as during the second stage build, we need to extract the kernel headers for GCC and other programs that need them. Note that we're installing them in a different location this time.
EXTRACTING THE KERNEL HEADER FILES
Change into the kernel source directory: /sources/linux-4.x
Change into this directory and issue the following command:
make mrproper
That done, we now call the
make command, specifying the header file output path; we do this in two steps because make wipes any files from the destination directory during this step. First, we extract the files:make INSTALL_HDR_PATH=dest headers_install
Now we remove any files that are not specifically needed, which leaves us with only the headers which are intended to be exposed to the user-land:
find dest/include \( -name .install -o -name ..install.cmd \) -delete
And secondly, we copy them to the proper location:
cp -rv dest/include/* /usr/include
Installing man Pages
In the
man-pages source directory, execute:make install
Building Glibc, Stage 3
This is our final build of glibc!
PATCHING THE SOURCE
To ensure compliance with the FHS, we need to patch the glibc source code. Execute the following commands to copy the patch file to the source directory and apply the patch:
cp ../glibc-2.24-fhs-1.patch .
patch -Np1 -i glibc-2.24-fhs-1.patch
CONFIGURE
../configure --prefix=/usr \
--enable-kernel=2.6.32 \
--enable-obsolete-rpc
These options are identical to those used to configure glibc in our first stage.
COMPILE
make
TEST
Unlike previous build stages, we now have all of the dependencies needed to run the tests against our binaries before we install them. This step is critical! Any problems with them build toolchain, the environment, library paths, etc., will likely reveal themselves at this point.
make check
Note that you will have some of the tests fail, in particular those related to the
getaddrinfo functions. Overall, your output from make check should look something like this:UNSUPPORTED: elf/tst-audit10
XPASS: elf/tst-protected1a
XPASS: elf/tst-protected1b
UNSUPPORTED: math/test-double-libmvec-alias-avx2
UNSUPPORTED: math/test-double-libmvec-alias-avx2-main
UNSUPPORTED: math/test-double-libmvec-alias-avx512
UNSUPPORTED: math/test-double-libmvec-alias-avx512-main
UNSUPPORTED: math/test-double-libmvec-sincos-avx2
UNSUPPORTED: math/test-double-libmvec-sincos-avx512
UNSUPPORTED: math/test-float-libmvec-alias-avx2
UNSUPPORTED: math/test-float-libmvec-alias-avx2-main
UNSUPPORTED: math/test-float-libmvec-alias-avx512
UNSUPPORTED: math/test-float-libmvec-alias-avx512-main
UNSUPPORTED: math/test-float-libmvec-sincosf-avx2
UNSUPPORTED: math/test-float-libmvec-sincosf-avx512
FAIL: posix/tst-getaddrinfo4
FAIL: posix/tst-getaddrinfo5
Summary of test results:
2 FAIL
2478 PASS
13 UNSUPPORTED
43 XFAIL
2 XPASS
make[1]: *** [Makefile:331: tests] Error 1
make[1]: Leaving directory '/sources/glibc-2.24'
make: *** [Makefile:9: check] Error 2
CREATE /ETC/LD.SO.CONF
make will throw an error if this file does not exist when the install is run.touch /etc/ld.so.conf
INSTALL
make install
INSTALL THE CONFIGURATION FILE AND RUNTIME FOR NSCD
cp -v ../nscd/nscd.conf /etc/nscd.conf
mkdir -pv /var/cache/nscd
INSTALLING LOCALE FILES
The following locales should be defined, if only to enable compliance with future tests.
Create The Locales Directory
mkdir -pv /usr/lib/locale
Install the Locale Definitions
localedef -i cs_CZ -f UTF-8 cs_CZ.UTF-8
localedef -i de_DE -f ISO-8859-1 de_DE
localedef -i de_DE@euro -f ISO-8859-15 de_DE@euro
localedef -i de_DE -f UTF-8 de_DE.UTF-8
localedef -i en_GB -f UTF-8 en_GB.UTF-8
localedef -i en_HK -f ISO-8859-1 en_HK
localedef -i en_PH -f ISO-8859-1 en_PH
localedef -i en_US -f ISO-8859-1 en_US
localedef -i en_US -f UTF-8 en_US.UTF-8
localedef -i es_MX -f ISO-8859-1 es_MX
localedef -i fa_IR -f UTF-8 fa_IR
localedef -i fr_FR -f ISO-8859-1 fr_FR
localedef -i fr_FR@euro -f ISO-8859-15 fr_FR@euro
localedef -i fr_FR -f UTF-8 fr_FR.UTF-8
localedef -i it_IT -f ISO-8859-1 it_IT
localedef -i it_IT -f UTF-8 it_IT.UTF-8
localedef -i ja_JP -f EUC-JP ja_JP
localedef -i ru_RU -f KOI8-R ru_RU.KOI8-R
localedef -i ru_RU -f UTF-8 ru_RU.UTF-8
localedef -i tr_TR -f UTF-8 tr_TR.UTF-8
localedef -i zh_CN -f GB18030 zh_CN.GB18030
GLIBC CONFIGURATION (POST-INSTALL)
We undertake the following steps to configure glibc after installing.
Add /etc/nsswitch.conf
cat > /etc/nsswitch.conf << "EOF"
# Begin /etc/nsswitch.conf
passwd: files
group: files
shadow: files
hosts: files dns
networks: files
protocols: files
services: files
ethers: files
rpc: files
# End /etc/nsswitch.conf
EOF
Add Timezone Files and Configure Our Timezone
For this step, we stay in the glibc build directory, and unzip the timezone data files to our current location.
tar -xf ../../tzdata2016f.tar.gz
Now we need to configure our timezones:
export ZONEINFO=/usr/share/zoneinfo
mkdir -pv $ZONEINFO/{posix,right}
for tz in etcetera southamerica northamerica europe africa antarctica \
asia australasia backward pacificnew systemv; do
zic -L /dev/null -d $ZONEINFO -y "sh yearistype.sh" ${tz}
zic -L /dev/null -d $ZONEINFO/posix -y "sh yearistype.sh" ${tz}
zic -L leapseconds -d $ZONEINFO/right -y "sh yearistype.sh" ${tz}
done
cp -v zone.tab zone1970.tab iso3166.tab $ZONEINFO
zic -d $ZONEINFO -p Etc/GMT
zic -d $ZONEINFO -p Etc/UTC
unset ZONEINFO
Set the Local Timezone
cp -v /usr/share/zoneinfo/Etc/UTC /etc/localtime
Configuring the Dynamic Loader
The dynamic loader is what allows shared objects (libraries) to be called at run-time by any given binary. In this step, inform glibc what paths to search when configuring the dynamic loader:
cat >> /etc/ld.so.conf << "EOF"
# Add an include directory
include /etc/ld.so.conf.d/*.conf
EOF
And last, create the directory referenced in
/etc/ld.so.conf:mkdir -pv /etc/ld.so.conf.d
Adjusting the Toolchain
Now that we've got a native glibc installed, we need to reconfigure our toolchain so that it looks for libraries and utilities inside the root filesystem hierarchy instead of looking in
/tools.BACKUP THE EXISTING LINKER
Let's backup the existing linker, and replace it with the one we've most recently built:
mv -v /tools/bin/{ld,ld-old}
mv -v /tools/$(uname -m)-pc-linux-gnu/bin/{ld,ld-old}
mv -v /tools/bin/{ld-new,ld}
ln -sv /tools/bin/ld /tools/$(uname -m)-pc-linux-gnu/bin/ld
RECONFIGURE GCC
We now need to alter the GCC so that it uses the new dynamic linker, headers and glibc libraries:
gcc -dumpspecs | sed -e 's@/tools@@g' \
-e '/\*startfile_prefix_spec:/{n;s@.*@/usr/lib/ @}' \
-e '/\*cpp:/{n;s@$@ -isystem /usr/include@}' > \
`dirname $(gcc --print-libgcc-file-name)`/specs
TEST THE GCC CONFIGURATION
It is imperative that GCC use the proper linker and libraries when compiling. We can check that using the following commands:
echo 'int main(){}' > dummy.c
cc dummy.c -v -Wl,--verbose &> dummy.log
readelf -l a.out | grep ': /lib'
Your output should be something like this:
[Requesting program interpreter: /lib64/ld-linux-x86-64.so.2]
Be certain that the interpreter path does not include the string 'tools'. If it does, GCC has not been properly reconfigured and will break.
Additionally, we should check to ensure GCC is using the proper glibc startup files:
grep -o '/usr/lib.*/crt[1in].*succeeded' dummy.log
Your output should resemble something like this:
/usr/lib/../lib64/crt1.o succeeded
/usr/lib/../lib64/crti.o succeeded
/usr/lib/../lib64/crtn.o succeeded
Installing binutils' Dependencies
The test suite included with binutils depends on the zlib and file packages. Let's install these before moving on to binutils itself.
INSTALLING ZLIB
Configure
zlib does not make use of a
configure script.Compile
make
Make check
make check
Install
make install
Post-configuration
The shared library needs to be moved to
/lib, and a symlink needs to be created in /usr/lib. This is to ensure compliance with FHS:mv -v /usr/lib/libz.so.* /lib
rm /usr/lib/libz.so
ln -sfv /lib/libz.so.1.2.8 /usr/lib/libz.so
INSTALLING FILE
This is another package upon which the binutils test suite depends.
Configure
./configure --prefix=/usr
Compile
make
Test
make check
Install
make install
Installing binutils (Stage 3)
This is our third (and final) installation of binutils.
START WITH FRESH SOURCE
Firstly, delete any existing binutils source directory, an re-extract the source code from the tar archive: rm -rf binutils-2.27 tar xf binutils-2.27.tar
CHECK TO ENSURE PTYS WORK IN THE JAIL
We need this to perform the tests against the binutils build. Execute: expect -c "spawn ls"
The output should be: spawn ls
CONFIGURE AND BUILD
Create the build directory as per usual, and issue the following commands to configure, build, test, and install binutils: ../configure --prefix=/usr --enable-shared --disable-werror make tooldir=/usr make -k check make tooldir=/usr install
Installing binutils Stage 3
This is our third (and final) installation of binutils.
START WITH A FRESH SOURCE
First, delete any existing binutils source directory, and re-extract the source code from the tar archive:
rm -rf binutils-2.27
tar xf binutils-2.27.tar
CHECK TO ENSURE PTYS WORK IN THE JAIL
We need this to perform the tests against the binutils build. Execute:
expect -c "spawn ls"
The output should be:
spawn ls
CONFIGURE AND BUILD
Create the build directory as usual, and issue the following commands to configure, build, test and install binutils:
../configure --prefix=/usr --enable-shared --disable-werror
make tooldir=/usr
make -k check
make tooldir=/usr install
Installing GMP
The GMP package contains several math libraries. These are used mainly with precision arithmetic.
Unlike glibc and gcc, GMP does not require the use of a build directory.
CONFIGURE AND COMPILE
The configure options are explained below. Execute:
./configure --prefix=/usr --enable-cxx --disable-static --docdir=/usr/share/doc/gmp-6.1.1
prefix:: Tells the configure script where the compiled binaries should be installed.enable-cxx:: Enables C++ support.disable-static:: Disables the generation of static libraries.docdir:: Specifies the prefix for installation documentation.
COMPILE
make && make html
TEST
make check 2>&1 | tee gmp-check-log
Ensure that all 190 of the tests have passed using the following command:
awk '/# PASS:/{total+=$3} ; END{print total}' gmp-check-log
INSTALL
make install && make install-html
Installing MPFR
Unlike glibc and gcc, MPFR does not require the use of a build directory.
CONFIGURE AND COMPILE
The configure options are explained below. Execute:
./configure --prefix=/usr --disable-static --enable-thread-safe --docdir=/usr/share/doc/mpfr-3.1.4
prefix:: Tells the configure script where the compiled binaries should be installed.disable-static:: Disables the generation of static libraries.enable-thread-safe:: Enables thread-handling in the library.docdir:: Specifies the prefix for installation documentation.
COMPILE
make && make html
TEST
make check
INSTALL
make install && make install-html
Installing MPC
The MPC package installs libraries which handle rounding and high-precision numbers.
Unlike glibc and gcc, MPC does not require the use of a build directory.
CONFIGURE AND COMPILE
./configure --prefix=/usr --disable-static --docdir=/usr/share/doc/mpc-1.0.3
COMPILE
make && make html
TEST
make check
INSTALL
make install && make install-html
Installing GCC
This is the fourth (and final) build of GCC. Make sure you've deleted the existing GCC directory, and re-extracted the source code from the tar file.
CONFIGURE AND COMPILE
Create the build directory, as per usual. Note that the
SED variable here prevents GCC from hard-coding a path to the sed binary.
Note as well that we do not copy the
mpc, mpfr or gap source packages into the GCC source directory, as we've installed these previously on the system.
Execute the following to begin the build:
export SED=sed
../configure --prefix=/usr --enable-languages=c,c++ --disable-multilib --disable-bootstrap --with-system-zlib
prefix:: Tells the configure script where the compiled binaries should be installed.enable-languages:: We only need C and C++ right now. Others can be added later.disable-multilib:: This functionality isn't supported on the x86_64 platform.disable-bootstrap:: We prevent GCC from performing a bootstrap build. As we've built GCC as a cross compiler, and then built GCC natively, we are now using the native build to compile GCC a third time. A bootstrapped build replicates these steps, which should be unnecessary if all of the testing has been executed as recommended.with-system-zib:: This instructsmaketo use the system zlib library instead of that bundled with GCC.
COMPILE
make -j2
TEST
Before we run the tests, we need to make sure the stack size is large enough to accommodate the testing software. We increase the stack size using the
ulimit command:ulimit -s 32768
And now run our tests:
make -k check
CHECK THE TEST RESULTS
You should have very few errors reported.
../contrib/test_summary
INSTALL
make install
ADD FHS-MANDATED SYMLINK:
ln -sv ../usr/bin/cpp /lib
ADD A CC LINK TO THE GCC BINARY
ln -sv gcc /usr/bin/cc
ADD COMPATIBILITY SYMLINKS
install -v -dm755 /usr/lib/bfd-plugins
ln -sfv ../../libexec/gcc/$(gcc -dumpmachine)/6.2.0/liblto_plugin.so /usr/lib/bfd-plugins/
SANITY CHECK
Once again, we stop here to check the functionality of our toolchain. Execute the following commands:
echo 'int main(){}' > dummy.c
cc dummy.c -v -Wl,--verbose &> dummy.log
readelf -l a.out | grep ': /lib'
Check GCC Startup
Now we want to check that GCC is using the proper set of files when it starts:
grep -o '/usr/lib.*/crt[1in].*succeeded' dummy.log
Result:
/usr/lib/gcc/i686-pc-linux-gnu/6.2.0/../../../crt1.o succeeded
/usr/lib/gcc/i686-pc-linux-gnu/6.2.0/../../../crti.o succeeded
/usr/lib/gcc/i686-pc-linux-gnu/6.2.0/../../../crtn.o succeeded
Check that GCC Uses the Proper Header Files
grep -B4 '^ /usr/include' dummy.log
Results:
##include <...> search starts here:
/usr/lib/gcc/i686-pc-linux-gnu/6.2.0/include
/usr/local/include
/usr/lib/gcc/i686-pc-linux-gnu/6.2.0/include-fixed
/usr/include
Verify the Linker Uses Proper Search Paths
grep 'SEARCH.*/usr/lib' dummy.log |sed 's|; |\n|g'
SEARCH_DIR("/usr/x86_64-unknown-linux-gnu/lib64")
SEARCH_DIR("/usr/local/lib64")
SEARCH_DIR("/lib64")
SEARCH_DIR("/usr/lib64")
SEARCH_DIR("/usr/x86_64-unknown-linux-gnu/lib")
SEARCH_DIR("/usr/local/lib")
SEARCH_DIR("/lib")
SEARCH_DIR("/usr/lib");
Ensure We're Using the Proper Libc Implementation
grep "/lib.*/libc.so.6 " dummy.log
Result:
attempt to open /lib/libc.so.6 succeeded
Ensure GCC Uses the Correct Dynamic Linker
grep found dummy.log
Result:
found ld-linux.so.2 at /lib/ld-linux.so.2
Cleanup
rm -v dummy.c a.out dummy.log
MOVE A MISPLACED FILE
Only execute this step if GCC has built correctly and all of the sanity checks are passed:
mkdir -pv /usr/share/gdb/auto-load/usr/lib
mv -v /usr/lib/*gdb.py /usr/share/gdb/auto-load/usr/lib
Installing Bzip2
This package does not require the use of a build directory. Be sure to start with a fresh source directory extracted from the tar file.
PATCH AND AMEND THE SOURCE
Change into the
bzip2 source directory, and run the following command to patch the source:patch -Np1 -i ../bzip2-1.0.6-install_docs-1.patch
Also, we need to amend the source code to ensure that symbolic links are installed using relative paths:
sed -i 's@\(ln -s -f \)$(PREFIX)/bin/@\1@' Makefile
This amendment ensures man page are installed to the proper location:
sed -i "s@(PREFIX)/man@(PREFIX)/share/man@g" Makefile
And now we need to reconstruct the
make file. The following commands cause make to use a different file; the makefile we create here adds a libb2.s shared library, and links the bzip2 utilities against it. Execute:make -f Makefile-libbz2_so
make clean
COMPILE AND INSTALL
make
make PREFIX=/usr install
COPY THE SHARED BINARY INTO THE APPROPRIATE DIRECTORY AND MAKE SYMBOLIC LINKS:
cp -v bzip2-shared /bin/bzip2
cp -av libbz2.so* /lib
ln -sv ../../lib/libbz2.so.1.0 /usr/lib/libbz2.so
rm -v /usr/bin/{bunzip2,bzcat,bzip2}
ln -sv bzip2 /bin/bunzip2
ln -sv bzip2 /bin/bzcat
Installing pkg-config
pkg-config does not require the use of a build directory.CONFIGURE AND COMPILE
The configure options are explained below. Execute:
./configure --prefix=/usr --with-internal-glib --disable-compile-warnings --disable-host-tool --docdir=/usr/share/doc/pkg-config-0.29.1
prefix:: Tells the configure script where the compiled binaries should be installed.with-internal-glib:: Allowspkg-configto use an internal glibc, as a system version is not available.disable-compile-warnings:: Prevents the use of compilation flags which could result in build failure.disable-host-tool:: Disables the creation of a hard-link to thepkg-configbinary.
COMPILE
make
TEST
make check
INSTALL
make install
Installing ncurses
This package does not require the use of a build directory. Be sure to start with a fresh source directory extracted from the tar file.
AMEND THE SOURCE
This command prevents the installation of a static library otherwise not handled by
configure:sed -i '/LIBTOOL_INSTALL/d' c++/Makefile.in
CONFIGURE AND COMPILE
The configure options are explained below. Execute:
./configure --prefix=/usr --mandir=/usr/share/man --with-shared --without-debug --without-normal --enable-pc-files --enable-widec
widec:: Causes wide-character libraries to be installed. Wide character libraries are usable by both multibyte and traditional locales.enable-pc-file:: Generates .pc files forpkg-config.without-normal:: Disables the building of most static libraries.
COMPILE
make
TEST
make check
INSTALL
make install
Move the shared libraries to the
/lib directory:mv -v /usr/lib/libncursesw.so.6* /lib
Because we've moved the library files, there is now a symlink to a non-existent file. So we need to re-create it:
ln -sfv ../../lib/$(readlink /usr/lib/libncursesw.so) /usr/lib/libncursesw.so
These symlinks make the wide-character libraries accessible to binaries which expect to find the non-wide libraries:
for lib in ncurses form panel menu ; do
rm -vf /usr/lib/lib${lib}.so
echo "INPUT(-l${lib}w)" > /usr/lib/lib${lib}.so
ln -sfv ${lib}w.pc /usr/lib/pkgconfig/${lib}.pc
done
This snippet ensures that binaries which look for
-lcurses at build time are still buildable:rm -vf /usr/lib/libcursesw.so
echo "INPUT(-lncursesw)" > /usr/lib/libcursesw.so
ln -sfv libncurses.so /usr/lib/libcurses.so
Install the documentation:
mkdir -v /usr/share/doc/ncurses-6.0
cp -v -R doc/* /usr/share/doc/ncurses-6.0
Installing attr
This package does not require the use of a build directory.
AMEND THE SOURCE
Amend the location of the documentation directory so that it uses a version number:
sed -i -e 's|/@pkg_name@|&-@pkg_version@|' include/builddefs.in
Prevent
make from overwriting man pages installed by the man-pages package:sed -i -e "/SUBDIRS/s|man[25]||g" man/Makefile
CONFIGURE AND COMPILE
Execute:
./configure --prefix=/usr --bindir=/bin --disable-static
COMPILE
make
TEST
make -j1 tests root-tests
INSTALL
make install install-dev install-lib
Change the permissions on the shared library:
chmod -v 755 /usr/lib/libattr.so
Move the shared library to
/lib:mv -v /usr/lib/libattr.so.* /lib
Which results in a missing library in
/usr/lib, which we recreate with a symlink:ln -sfv ../../lib/$(readlink /usr/lib/libattr.so) /usr/lib/libattr.so
Installing acl
This package does not require the use of a build directory.
AMEND THE SOURCE
Amend the location of the documentation directory so that it uses a version number:
sed -i -e 's|/@pkg_name@|&-@pkg_version@|' include/builddefs.in
Fix some broken tests:
sed -i "s:| sed.*::g" test/{sbits-restore,cp,misc}.test
Fix a bug which causes
getfacl -e to segfault on long group names:sed -i -e "/TABS-1;/a if (x > (TABS-1)) x = (TABS-1);" libacl/__acl_to_any_text.c
CONFIGURE AND COMPILE
Execute:
./configure --prefix=/usr --bindir=/bin --disable-static --libexecdir=/usr/lib
COMPILE
make
INSTALL
make install install-dev install-lib
Change the permissions on the shared library:
chmod -v 755 /usr/lib/libacl.so
Move the shared library to
/lib:mv -v /usr/lib/libacl.so.* /lib
Which results in a missing library in
/usr/lib, which we recreate with a symlink:ln -sfv ../../lib/$(readlink /usr/lib/libacl.so) /usr/lib/libacl.so
Installing libpcap
This package does not require the use of a build directory.
AMEND THE SOURCE
Prevent
make from installing a static library:sed -i '/install.*STALIBNAME/d' libcap/Makefile
CONFIGURE AND COMPILE
The package doesn't make use of a
configure script:make
INSTALL
The
RAISE_SETFCAP variable defined on the command line prevents the use of setcap on the resulting library. This is necessary if the kernel or filesystem doesn't not support extended capabilities.make RAISE_SETFCAP=no prefix=/usr install
chmod -v 755 /usr/lib/libcap.so
Move the shared library to
/lib:mv -v /usr/lib/libcap.so.* /lib
Which results in a missing library in
/usr/lib, which we recreate with a symlink:ln -sfv ../../lib/$(readlink /usr/lib/libcap.so) /usr/lib/libcap.so
Installing sed
This package does not require the use of a build directory. Be sure to start with a fresh source directory extracted from the tar file.
CONFIGURE
./configure --prefix=/usr --bindir=/bin --htmldir=/usr/share/doc/sed-4.2.2
COMPILE
make
make html
TEST
Note that the 'version' test may fail, resulting in a total of 5 failed tests of 66:
make check
INSTALL
make install
make -C doc install-html
Installing shadow
This package does not require the use of a build directory.
AMEND THE SOURCE
Prevent
make from installing groups-related programs and related man pages. These will be installed by the coreutils package.sed -i '/install.*STALIBNAME/d' libcap/Makefile
find man -name Makefile.in -exec sed -i 's/groups\.1 / /' {} \;
find man -name Makefile.in -exec sed -i 's/getspnam\.3 / /' {} \;
find man -name Makefile.in -exec sed -i 's/passwd\.5 / /' {} \;
Enable the use of the SHA-512 algorithm for password encryption:
sed -i -e 's@#ENCRYPT_METHOD DES@ENCRYPT_METHOD SHA512@' etc/login.defs
Change the location of user mailboxes from
/var/spool/mail to /var/mail:sed -i -e 's@/var/spool/mail@/var/mail@' etc/login.defs
This amendment renders the 'user add' binary consistent with BROOT:
sed -i 's/1000/999/' etc/useradd
CONFIGURE
./configure --sysconfdir=/etc --with-group-name-max-length=32
COMPILE AND INSTALL
make && make install
Move a misplaced binary to its proper location:
mv -v /usr/bin/passwd /bin
POST-INSTALL CONFIGURATION
To enable shadowed passwords, run the following command:
pwconv
To enable shadowed groups, execute this command:
grpconv
Set the root Password
Now that we've installed the
/etc/passwd file and the utilities to manage passwords, change the root password.
If you receive an error message about root not existing in
/etc/passwd, there is likely a problem with the file.Installing psmisc
This package does not require the use of a build directory.
CONFIGURE
./configure --prefix=/usr
COMPILE
make
INSTALL
make install
MOVE
Move the 'killall' and 'fuser' binaries to FHS-compliant locations:
mv -v /usr/bin/fuser /bin
mv -v /usr/bin/killall /bin
Installing IANA-etc
This package does not require the use of a build directory.
CONFIGURE
This package does not make use of a configuration script.
COMPILE
make
INSTALL
make install
Installing M4
This package does not require the use of a build directory.
CONFIGURE
./configure --prefix=/usr
COMPILE
make
TEST
M4 may fail the 'test-update-copyright' test; you check this by using
cat to check the contents of tests/test-suite.log.make check
INSTALL
make install
Installing bison
This package does not require the use of a build directory.
CONFIGURE
./configure --prefix=/usr --docdir=/usr/share/doc/bison-3.0.4
COMPILE
make
INSTALL
make install
Installing flex
This package does not require the use of a build directory.
CONFIGURE
./configure --prefix=/usr --docdir=/usr/share/doc/flex-2.6.1
COMPILE
make
INSTALL
make install
COMPATIBILITY SYMLINK
flex is predated by a software package by the name of lex. Some user-land binaries may be expecting lex to be installed, and may not call flex. However, this software package does provide for the emulation of lex using a symlink:ln -sv flex /usr/bin/lex
Installing grep
This package does not require the use of a build directory.
CONFIGURE
./configure --prefix=/usr --bindir=/bin
COMPILE
make
TEST
make check
INSTALL
make install
Installing readline
This package does not require the use of a build directory. Be sure to start with a fresh source directory extracted from the tar file.
PATCH AND AMEND THE SOURCE
Change to the readline source directory, and run the following command to patch the source:
patch -Np1 -i ../readline-6.3-upstream_fixes-3.patch
Reinstalling this package results in old libraries being moved, with the suffix
.old attached to their filename. This can trigger bugs in ldconfig. We can avoid this behavior by removing the renaming:sed -i '/MV.*old/d' Makefile.in
sed -i '/{OLDSUFF}/c:' support/shlib-install
CONFIGURE
./configure --prefix=/usr --disable-static --docdir=/usr/share/doc/readline-6.3
COMPILE AND INSTALL
make SHLIB_LIBS=-lncurses
make SHLIB_LIBS=-lncurses install
COPY THE SHARED BINARY INTO THE APPROPRIATE DIRECTORY AND MAKE SYMBOLIC LINKS:
mv -v /usr/lib/lib{readline,history}.so.* /lib
ln -sfv ../../lib/$(readlink /usr/lib/libreadline.so) /usr/lib/libreadline.so
ln -sfv ../../lib/$(readlink /usr/lib/libhistory.so ) /usr/lib/libhistory.so
INSTALL THE DOCUMENTATION
install -v -m644 doc/*.{ps,pdf,html,dvi} /usr/share/doc/readline-6.3
Installing bash
This package does not require the use of a build directory. Be sure to start with a fresh source directory extracted from the tar file.
PATCH
patch -Np1 -i ../bash-4.3.30-upstream_fixes-3.patch
CONFIGURE
./configure --prefix=/usr --docdir=/usr/share/doc/bash-4.3.30 --without-bash-malloc --with-installed-readline
COMPILE
make
TEST
First, we need to change the permissions on the source tree so that the nobody user can write:
chown -Rv nobody
Now, execute the tests as the nobody user:
su nobody -s /bin/bash -c "PATH=$PATH make tests"
INSTALL
make install
mv -vf /usr/bin/bash /bin
TO USE THE NEWLY INSTALLED BASH:
exec /bin/bash --login +h
Installing bc
This package does not require the use of a build directory.
PATCH
patch -Np1 -i ../bc-1.06.95-memory_leak-1.patch
CONFIGURE
./configure --prefix=/usr --with-readline --mandir=/usr/share/man --infodir=/usr/share/info
COMPILE
make
TEST
echo "quit" | ./bc/bc -l Test/checklib.b
INSTALL
make install
Installing lib tool
This package does not require the use of a build directory.
CONFIGURE
./configure --prefix=/usr
COMPILE
make
TEST
Libtool will fail several tests, due to unmet dependencies on the
automake package.make check
INSTALL
make install
Installing GBDM
This package does not require the use of a build directory.
CONFIGURE
./configure --prefix=/usr --disable-static --enable-libgdbm-compat
COMPILE
make
TEST
make check
INSTALL
make install
Installing Gperf
This package does not require the use of a build directory.
CONFIGURE
./configure --prefix=/usr --docdir=/usr/share/doc/gperf-3.0.4
COMPILE
make
TEST
make -j1 check
INSTALL
make install
Installing expat
This package does not require the use of a build directory.
CONFIGURE
./configure --prefix=/usr --disable-static
COMPILE
make
TEST
make check
INSTALL
make install
install -v -dm755 /usr/share/doc/expat-2.2.0
install -v -m644 doc/*.{html,png,css} /usr/share/doc/expat-2.2.0
Installing inetutils
This package does not require the use of a build directory.
CONFIGURE
./configure --prefix=/usr --localstatedir=/var --disable-logger --disable-whois --disable-rcp --disable-rexec --disable-rlogin --disable-rsh --disable-servers
disable-logger:: This prevents the installation of the logger program; this same program is provided (albeit, a more recent version) by theutil-linuxpackage.disable-whois:: Disables the building of thewhoisclient.disable-rcp/rexec/rlogin/rsh:: Disables the building of obsolete programs whose functionality has been replaced by OpenSSH.disable-servers:: This disables the installation of a number of network services included in the package. Most of these are insecure.
COMPILE
make
TEST
make check
INSTALL
make install
mv -v /usr/bin/{hostname,ping,ping6,traceroute} /bin
mv -v /usr/bin/ifconfig /sbin
Installing PERL
This package does not require the use of a build directory. Be sure to start with a fresh source directory extracted from the tar file.
PRE-CONFIGURATION
Install the
/etc/hosts file, which is required by PERL's configuration files:echo -e "127.0.0.1\tlocalhost\t$(hostname)" > /etc/hosts
Export the following variables:
export BUILD_ZLIB=False
export BUILD_BZIP2=0
CONFIGURE
PERL uses a special configuration script, as we saw previously:
sh Configure -des -Dprefix=/usr -Dvendorprefix=/usr -Dman1dir=/usr/share/man/man1 -Dman3dir=/usr/share/man/man3 -Dpager="/usr/bin/less -isR" -Duseshrplib
Dvendorprefix=/usr:: Notifies PERL where packages should install their PERL modules.Dpager="/usr/bin/less -isR":: Instructs PERL to uselessas a pager instead ofmore.Dman3dir=/usr/share/man/man3:: PERL depends ongroff, which is not installed yet. This directive instructsmaketo build man pages anyway.Duseshrplib:: Build a shared library.
MAKE
make
TEST
make -k test
INSTALL
make install
CLEANUP
unset BUILD_ZLIB BUILD_BZIP2
Installing XML::Parser
This is a PERL module which incorporates the functionality of the expat binary into PERL.
CONFIGURATION
perl Makefile.PL
COMPILE
make
TEST
make test
INSTALL
make install
Installing intltool
This package does not require the use of a build directory.
AMEND THE SOURCE
PERL version 5.22 and up throw a warning unless the source is amended as follows:
sed -i 's:\\\${:\\\$\\{:' intltool-update.in
CONFIGURATION
./configure --prefix=/usr
COMPILE
make
TEST
make check
INSTALL
make install
install -v -Dm644 doc/I18N-HOWTO /usr/share/doc/intltool-0.51.0/I18N-HOWTO
Installing autoconf
This package does not require the use of a build directory.
CONFIGURATION
./configure --prefix=/usr
COMPILE
make
TEST
make check
INSTALL
make install
Installing automake
This package does not require the use of a build directory.
AMEND THE SOURCE CODE
This fixes warnings thrown by PERL 5.22 and above.
sed -i 's:/\\\${:/\\\$\\{:' bin/automake.in
CONFIGURATION
./configure --prefix=/usr --docdir=/usr/share/doc/automake-1.15
COMPILE
make
TEST
Some of the tests link to the wrong version of flex; we use the sed command to fix this:
sed -i "s:./configure:LEXLIB=/usr/lib/libfl.a &:" t/lex-{clean,depend}-cxx.sh
make -j2 check
INSTALL
make install
Installing xz
This package does not require the use of a build directory.
AMEND THE SOURCE CODE
This fixes warnings thrown by PERL 5.22 and above.
sed -e '/mf\.buffer = NULL/a next->coder->mf.size = 0;' -i src/liblzma/lz/lz_encoder.c
CONFIGURATION
./configure --prefix=/usr --disable-static --docdir=/usr/share/doc/xz-5.2.
COMPILE
make
TEST
make check
INSTALL
make install
mv -v /usr/bin/{lzma,unlzma,lzcat,xz,unxz,xzcat} /bin
mv -v /usr/lib/liblzma.so.* /lib
ln -svf ../../lib/$(readlink /usr/lib/liblzma.so) /usr/lib/liblzma.so
Installing kmod
This package does not require the use of a build directory.
CONFIGURATION
./configure --prefix=/usr --bindir=/bin --sysconfdir=/etc --with-rootlibdir=/lib --with-xz --with-zlib
COMPILE
make
INSTALL
We create symlinks here, which provide backwards compatibility with the module-init tools, which previously provided loadable module support for the kernel.
make install
for target in depmod insmod lsmod modinfo modprobe rmmod; do
ln -sfv ../bin/kmod /sbin/$target
done
ln -sfv kmod /bin/lsmod
Installing gettext
This package does not require the use of a build directory. Be sure to start with a fresh source directory extracted from the tar file.
CONFIGURATION
./configure --prefix=/usr --disable-static --docdir=/usr/share/doc/gettext-0.19.8.1
COMPILE
make
TEST
make check
INSTALL
make install
chmod -v 0755 /usr/lib/preloadable_libintl.so
Installing procps-ng
This package does not require the use of a build directory.
CONFIGURATION
./configure --prefix=/usr --exec-prefix= --libdir=/usr/lib --docdir=/usr/share/doc/procps-ng-3.3.12 --disable-static --disable-kill
COMPILE
make
TEST
We need to modify the test code so that it does not rely on the presence of a tty device; otherwise, some tests will fail:
sed -i -r 's|(pmap_initname)\\\$|\1|' testsuite/pmap.test/pmap.exp
make check
INSTALL
make install
mv -v /usr/lib/libprocps.so.* /lib
ln -sfv ../../lib/$(readlink /usr/lib/libprocps.so) /usr/lib/libprocps.so
Installing e2fsprogs
This package does require the use of a
build directory like binutils, GCC and glibc.AMEND THE SOURCE
We amend one of the test scripts here:
sed -i -e 's:\[\.-\]::' tests/filter.sed
CONFIGURE
The environment variables defined here instruct
configure to look for libraries in the specified locations:export LIBS=-L/tools/lib
export CFLAGS=-I/tools/include
export PKG_CONFIG_PATH=/tools/lib/pkgconfig
../configure --prefix=/usr --bindir=/bin --with-root-prefix="" --enable-elf-shlibs --disable-libblkid --disable-libuuid --disable-uuidd --disable-fsck
bindir=/bin:: Ensure that the compiled binaries are installed in/liband/sbin.enable-elf-shlibs:: Creates shared libraries used by the binaries installed as part of the package.disable:: Prevents the installation of the specified libraries, as more recent versions are installed by theutil-linuxpackage.
COMPILE
make
TEST
For the tests to run properly, we need to link some shared libraries to a place where the tests can find them:
ln -sfv /tools/lib/lib{blk,uu}id.so.1 lib
make LD_LIBRARY_PATH=/tools/lib check
INSTALL
make install
make install-libs
chmod -v u+w /usr/lib/{libcom_err,libe2p,libext2fs,libss}.a
gunzip -v /usr/share/info/libext2fs.info.gz
install-info --dir-file=/usr/share/info/dir /usr/share/info/libext2fs.info
makeinfo -o doc/com_err.info ../lib/et/com_err.texinfo
install -v -m644 doc/com_err.info /usr/share/info
install-info --dir-file=/usr/share/info/dir /usr/share/info/com_err.info
CLEANUP
DO NOT FORGET TO UNSET THESE ENVIRONMENT VARIABLES!
unset LIBS CFLAGS PKG_CONFIG_PATH
Installing coreutils
This package does not require the use of a build directory. Be sure to start with a fresh source directory extracted from the tar file.
PATCH THE SOURCE
patch -Np1 -i ../coreutils-8.25-i18n-2.patch
CONFIGURE
The variable defined here allows
coreutils to be built as root:FORCE_UNSAFE_CONFIGURE=1 ./configure --prefix=/usr --enable-no-install-program=kill,uptime
enable-no-install-program:: Prevents the installation of binaries which will be installed by other packages.
COMPILE
FORCE_UNSAFE_CONFIGURE=1 make
TEST
For the tests to run properly, we need to link some shared libraries to a place where the tests can find them:
make NON_ROOT_USERNAME=nobody check-root
Some tests must be run as the nobody user, and require the user be part of more than one group:
echo "dummy:x:1000:nobody" >> /etc/group
Change the permissions so the tests can be run by the nobody user:
chown -Rv nobody .
And now we run the remainder of the tests:
su nobody -s /bin/bash -c "PATH=$PATH make RUN_EXPENSIVE_TESTS=yes check"
INSTALL
make install
mv -v /usr/bin/{cat,chgrp,chmod,chown,cp,date,dd,df,echo} /bin
mv -v /usr/bin/{false,ln,ls,mkdir,mknod,mv,pwd,rm} /bin
mv -v /usr/bin/{rmdir,stty,sync,true,uname} /bin
mv -v /usr/bin/chroot /usr/sbin
mv -v /usr/share/man/man1/chroot.1 /usr/share/man/man8/chroot.8
sed -i s/\"1\"/\"8\"/1 /usr/share/man/man8/chroot.8
mv -v /usr/bin/{head,sleep,nice,test,[} /bin
CLEANUP
Remove the dummy group we created for testing:
sed -i '/dummy/d' /etc/group
Installing Diffutils
This package does not require the use of a build directory. Be sure to start with a fresh source directory extracted from the tar file.
AMEND THE SOURCE
We need to amend the makefiles so that the locale files are installed:
sed -i 's:= @mkdir_p@:= /bin/mkdir -p:' po/Makefile.in.in
CONFIGURE
./configure --prefix=/usr
COMPILE
make
TEST
The
test-update-copyright failure is expected.make test
INSTALL
make install
Installing gawk
This package does not require the use of a build directory. Be sure to start with a fresh source directory extracted from the tar file.
CONFIGURE
./configure --prefix=/usr
COMPILE
make
CHECK
make check
INSTALL
make install
INSTALL DOCUMENTATION
mkdir -v /usr/share/doc/gawk-4.1.3
cp -v doc/{awkforai.txt,*.{eps,pdf,jpg}} /usr/share/doc/gawk-4.1.3
Installing findutils
This package does not require the use of a build directory. Be sure to start with a fresh source directory extracted from the tar file.
CONFIGURE
./configure --prefix=/usr --localstatedir=/var/lib/locate
COMPILE
make
TEST
make check
INSTALL
make install
mv -v /usr/bin/find /bin
sed -i 's|find:=${BINDIR}|find:=/bin|' /usr/bin/updatedb
Installing groff
CONFIGURATION
The
gruff binary expects to find a "PAGE" variable in the environment which defines the default page size. This is normally stored in /etc/papersize; we provide a value on the command-line here.export PAGE=letter
./configure --prefix=/usr
BUILD
make
INSTALL
make install
Installing GRUB
CONFIGURE
./configure --prefix=/usr --sbindir=/sbin --sysconfdir=/etc --disable-efiemu --disable-werror
disable-efiemu:: Disables EFI emulation and testing.
COMPILE
make
INSTALL
make install
Installing less
This package does not require the use of a build directory. Be sure to start with a fresh source directory extracted from the tar file.
CONFIGURE
./configure --prefix=/usr --sysconfdir=/etc
COMPILE
make
INSTALL
make install
Installing gzip
This package does not require the use of a build directory. Be sure to start with a fresh source directory extracted from the tar file.
CONFIGURE
./configure --prefix=/usr
COMPILE
make
TEST
make check
INSTALL
make install
mv -v /usr/bin/gzip /bin
Installing iproute2
This package does not require the use of a build directory.
AMEND THE SOURCE
We amend the source here to remove a dependency on Berkeley DB, which is not installed.
sed -i /ARPD/d Makefile
sed -i 's/arpd.8//' man/man8/Makefile
rm -v doc/arpd.sgml
This command removes a dependency on
iptables:sed -i 's/m_ipt.o//' tc/Makefile
CONFIGURE
There is no separate configure step.
COMPILE
make
INSTALL
make DOCDIR=/usr/share/doc/iproute2-4.7.0 install
Installing kbd
This package does not require the use of a build directory.
PATCH AND AMEND THE SOURCE
patch -Np1 -i ../kbd-2.0.3-backspace-1.patch
The following commands ensure the
resizecons binary is not built:sed -i 's/\(RESIZECONS_PROGS=\)yes/\1no/g' configure
sed -i 's/\(RESIZECONS_PROGS=\)yes/\1no/g' configure
CONFIGURE
PKG_CONFIG_PATH=/tools/lib/pkgconfig ./configure --prefix=/usr --disable-vlock
disable-block:: Prevents the vlock utility from being built as it depends on the PAM library, which we have not installed.
COMPILE
make
TEST
make check
INSTALL
make install
mkdir -v /usr/share/doc/kbd-2.0.3
cp -R -v docs/doc/* /usr/share/doc/kbd-2.0.3
Installing libpipeline
This package does not require the use of a build directory.
CONFIGURE
PKG_CONFIG_PATH=/tools/lib/pkgconfig ./configure --prefix=/usr
COMPILE
make
TEST
make check
INSTALL
make install
Installing make
This package does not require the use of a build directory.
CONFIGURE
./configure --prefix=/usr
COMPILE
make
TEST
make check
INSTALL
make install
Installing patch
This package does not require the use of a build directory. Be sure to start with a fresh source directory extracted from the tar file.
CONFIGURE
./configure --prefix=/usr
COMPILE
make
TEST
make check
INSTALL
make install
Installing sysklogd
This package does not require the use of a build directory.
AMEND THE SOURCE
The following commands address problems that cause
sysklogd to segment fault, as well as remove a reference to an obsolete data structure:sed -i '/Error loading kernel symbols/{n;n;d}' ksym_mod.c
sed -i 's/union wait/int/' syslogd.c
CONFIGURE
This package does not make use of a
configure script.COMPILE
make
INSTALL
make BINDIR=/sbin install
POST-INSTALL CONFIGURATION
Create
/etc/syslog.conf with the following contents:auth,authpriv.* -/var/log/auth.log
*.*;auth,authpriv.none -/var/log/sys.log
daemon.* -/var/log/daemon.log
kern.* -/var/log/kern.log
mail.* -/var/log/mail.log
user.* -/var/log/user.log
*.emerg *
Install sysvinit
This package does not require the use of a build directory.
PATCH
patch -Np1 -i ../sysvinit-2.88dsf-consolidated-1.patch
CONFIGURE
This program does not make use of a
configure script.COMPILE
make -C src
INSTALL
make -C src install
Install eudev
This package does not require the use of a build directory.
AMEND THE SOURCE
First, we need to amend one of the test scripts:
sed -r -i 's|/usr(/bin/test)|\1|' test/udev-test.pl
And now we prevent the
/tools directory from being hard-coded as a library path into the binary; we do this by appending the following variables to the config.cache file:cat > config.cache << "EOF"
HAVE_BLKID=1
BLKID_LIBS="-lblkid"
BLKID_CFLAGS="-I/tools/include"
EOF
CONFIGURE
./configure --prefix=/usr --bindir=/sbin --sbindir=/sbin --libdir=/usr/lib --sysconfdir=/etc --libexecdir=/lib --with-rootprefix= --with-rootlibdir=/lib --enable-manpages --disable-static --config-cache
COMPILE
LIBRARY_PATH=/tools/lib make
TEST
First, we need to create some directories required by the testing scripts:
mkdir -pv /lib/udev/rules.d
mkdir -pv /etc/udev/rules.d
And run the tests:
make LD_LIBRARY_PATH=/tools/lib check
INSTALL
make LD_LIBRARY_PATH=/tools/lib install
tar -xvf ../udev-BROOT-20140408.tar.bz2
make -f udev-BROOT-20140408/Makefile.BROOT install
POST-INSTALL CONFIGURATION
LD_LIBRARY_PATH=/tools/lib udevadm hwdb --update
Installing util-linux
This package does not require the use of a build directory.
CONFIGURATION
As per FHS, we will use
/var/lib/hwclock instead of /etc for our daytime file:mkdir -pv /var/lib/hwclock
And now configure the package:
./configure ADJTIME_PATH=/var/lib/hwclock/adjtime --docdir=/usr/share/doc/util-linux-2.28.1 --disable-chfn-chsh --disable-login --disable-nologin --disable-su --disable-setpriv --disable-runuser --disable-pylibmount --disable-static --without-python --without-systemd --without-systemdsystemunitdir
COMPILE
make
TEST
We do not run the tests for this package, as they will not run without specific kernel options. As well, some of these tests have been known to damage hardware.
INSTALL
make install
Installing man-DB
This package does not require the use of a build directory.
CONFIGURE
./configure --prefix=/usr --docdir=/usr/share/doc/man-db-2.7.5 --sysconfdir=/etc --disable-setuid --with-browser=/usr/bin/lynx --with-vgrind=/usr/bin/vgrind --with-grap=/usr/bin/grap
COMPILE
make
TEST
make check
INSTALL
make install
POST-INSTALL CONFIGURATION:
Remove a reference to a non-existent user:
sed -i "s:man root:root root:g" /usr/lib/tmpfiles.d/man-db.conf
Installing tar
This package does not require the use of a build directory.
CONFIGURE
We set the
FORCE_UNSAFE_CONFIGURE variable here to allow compilation using the root account.FORCE_UNSAFE_CONFIGURE=1 ./configure --prefix=/usr --bindir=/bin
COMPILE
make
TEST
make check
INSTALL
make install
make -C doc install-html docdir=/usr/share/doc/tar-1.29
Installing texinfo
This package does not require the use of a build directory.
CONFIGURE
./configure --prefix=/usr --disable-static
COMPILE
make
TEST
make check
INSTALL
make install
make TEXMF=/usr/share/texmf install-tex
Installing vim
This package does not require the use of a build directory.
AMEND THE SOURCE CODE
We amend the source code so that the default location of the
vimrc file is /etc:echo '#define SYS_VIMRC_FILE "/etc/vimrc"' >> src/feature.h
CONFIGURE
./configure --prefix=/usr
COMPILE
make
TEST
make -j1 test
INSTALL
make install
POST-INSTALL CONFIGURATION
Here we install the symlinks for the
vi binaries and man pages, so when people execute vi, they actually call the 'vim' binary.ln -sv vim /usr/bin/vi
for L in /usr/share/man/{,*/}man1/vim.1; do
ln -sv vim.1 $(dirname $L)/vi.1
done
Here we symlink vim so that it appears versioned (in the interest of consistency):
ln -sv ../vim/vim74/doc /usr/share/doc/vim-7.4
Now we can create the vimrc file:
cat > /etc/vimrc << "EOF"
" Begin /etc/vimrc
set nocompatible
set backspace=2
syntax on
if (&term == "iterm") || (&term == "putty")
set background=dark
endif
" End /etc/vimrc
EOF
Stripping Binaries and Libraries
We can decrease the size of the compiled binaries and libraries by stripping out the debug symbols. This step is optional, but unless you intend to perform debugging, the symbols serve only to consume space.
This is a good time to backup your destination drive yet again — a single typo here can destroy all of the work performed thus far.
LOGOUT/LOGIN
It is very important to note that none of the binaries we intend to strip are running. To accomplished this, we can exit the chroot jail and re-enter it with the following two commands:
logout
chroot $BROOT /tools/bin/env -i HOME=/root TERM=$TERM PS1='\u:\w\$ ' PATH=/bin:/usr/bin:/sbin:/usr/sbin /tools/bin/bash --login
STRIP
A large number of 'file format' errors will be reported by these commands. These can be ignored; the files in question are usually script files.
/tools/bin/find /usr/lib -type f -name \*.a \ -exec /tools/bin/strip --strip-debug {} ';'
/tools/bin/find /lib /usr/lib -type f -name \*.so* -exec /tools/bin/strip --strip-unneeded {} ';'
/tools/bin/find /{bin,sbin} /usr/{bin,sbin,libexec} -type f -exec /tools/bin/strip --strip-all {} ';'
Section 6
Cleanup
Now we can clean some of the extra files left behind by various testing processes:
rm -rf /tmp/*
CLEANUP UNUSED LIBRARIES
There are also some library files used only for testing we can cleanup:
rm -f /usr/lib/lib{bfd,opcodes}.a
rm -f /usr/lib/libbz2.a
rm -f /usr/lib/lib{com_err,e2p,ext2fs,ss}.a
rm -f /usr/lib/libltdl.a
rm -f /usr/lib/libfl.a
rm -f /usr/lib/libfl_pic.a
rm -f /usr/lib/libz.a
Entering the Jail
From this point forward, the jail can be re-entered after it has been exited by issuing the following command:
chroot "$BROOT" /usr/bin/env -i \
HOME=/root TERM="$TERM" PS1='\u:\w\$ ' \
PATH=/bin:/usr/bin:/sbin:/usr/sbin \
/bin/bash --login
PSEUDO AND VIRTUAL FILESYSTEMS
These must be re-created and mounted each time you re-enter the jail.
Installing the Bootscripts
These scripts are used to configure the system at boot and ensure an orderly shutdown.
BROOT BOOTSCRIPTS
We're going to make use of the "Linux From Scratch" bootscripts, which we downloaded along with the rest of our source code.
These install our rc scripts, as well as the scripts needed to bring the system up and down.
Find these in the
/sources directory, un-tar them, and install them:make install
SYSVINIT BOOTSCRIPTS
Once the kernel is loaded, the
init program is usually executed. init needs to be given some configuration directives, which we place in /etc/inittab. Create this file now with the following content:id:3:initdefault:
si::sysinit:/etc/rc.d/init.d/rc S
l0:0:wait:/etc/rc.d/init.d/rc 0
l1:S1:wait:/etc/rc.d/init.d/rc 1
l2:2:wait:/etc/rc.d/init.d/rc 2
l3:3:wait:/etc/rc.d/init.d/rc 3
l4:4:wait:/etc/rc.d/init.d/rc 4
l5:5:wait:/etc/rc.d/init.d/rc 5
l6:6:wait:/etc/rc.d/init.d/rc 6
ca:12345:ctrlaltdel:/sbin/shutdown -t1 -a -r now
su:S016:once:/sbin/sulogin
1:2345:respawn:/sbin/agetty --noclear tty1 9600
2:2345:respawn:/sbin/agetty tty2 9600
3:2345:respawn:/sbin/agetty tty3 9600
4:2345:respawn:/sbin/agetty tty4 9600
5:2345:respawn:/sbin/agetty tty5 9600
6:2345:respawn:/sbin/agetty tty6 9600
Installing Network Devices
Network devices are managed using
udev, which provides a script that generates the initial rules for the device. These can be generated by running:bash /lib/udev/init-net-rules.sh
The rules file which creates network devices can be examined if needed:
cat /etc/udev/rules.d/70-persistent-net.rules
Note that you must have the appropriate kernel module loaded (or compiled into the kernel) for your network device to be recognized and used.
CONFIGURING NETWORK DEVICES
The following content must be placed in
/etc/sysconfig/ifconfig.eth0 to configure the network device initially:cd /etc/sysconfig/
cat > ifconfig.eth0 << "EOF"
ONBOOT=yes
IFACE=eth0
SERVICE=ipv4-static
IP=192.168.1.2
GATEWAY=192.168.1.1
PREFIX=24
BROADCAST=192.168.1.255
EOF
CONFIGURING DOMAIN NAME SERVICE (DNS) RESOLUTION
By default, glibc looks in
/etc/resolv.conf to determine where to send DNS queries. Create this file with the following contents:domain localdomain
nameserver 8.8.8.8
nameserver 8.8.4.4
CONFIGURING THE HOSTNAME
The hostname is stored in
/etc/hostname. The hostname should not be a fully qualified domain name. Create this file with the hostname you prefer.CONFIGURING /ETC/HOSTS
This file is where we provide IP address to hostname/FQDN mappings. Any number of hosts can be contained in this file, although it is usually better to rely on DNS.
We'll begin this file with the localhost mapping; create
/etc/hosts with the following contents:127.0.0.1 localhost localhost.localdomain
Miscellaneous Files
RC.SITE
The
/etc/rc.site file provides settings that are used by the System V scripts. We're going to create this file with the following content:DISTRO="Linux From Scratch" # The distro name
DISTRO_CONTACT="BROOT-dev@linuxacademy.com" # Bug report address
DISTRO_MINI="BROOT" # Short name used in filenames for distro config
IPROMPT="yes" # Whether to display the interactive boot prompt
itime="3" # The amount of time (in seconds) to display the prompt
wlen=$(echo "Welcome to ${DISTRO}" | wc -c )
welcome_message="Welcome to ${INFO}${DISTRO}${NORMAL}"
# Set scripts to skip the file system check on reboot
FASTBOOT=no
# Skip reading from the console
HEADLESS=no
# Write out fsck progress if yes
VERBOSE_FSCK=yes
# Speed up boot without waiting for settle in udev
OMIT_UDEV_SETTLE=n
# Speed up boot without waiting for settle in udev_retry
OMIT_UDEV_RETRY_SETTLE=no
# Skip cleaning /tmp if yes
SKIPTMPCLEAN=no
# For setclock
#UTC=1
#CLOCKPARAMS=
# For consolelog (Note that the default, 7=debug, is noisy)
#LOGLEVEL=7
# Delay between TERM and KILL signals at shutdown
KILLDELAY=3
/ETC/PROFILE
This file is read by various shells (notably bash) to set environment defaults. We're going to create this file with the following content:
if [ -x /usr/bin/id ]; then
if [ -z "$EUID" ]; then
# ksh workaround
EUID=`id -u`
UID=`id -ru`
fi
USER="`id -un`"
LOGNAME=$USER
MAIL="/var/spool/mail/$USER"
fi
HOSTNAME=/usr/bin/hostname 2>/dev/null
HISTSIZE=1000
PATH=/usr/local/bin:/usr/local/sbin:/usr/bin:/usr/sbin:/sbin:/bin
export PATH USER LOGNAME MAIL HOSTNAME HISTSIZE
This file can be amended a number of ways to meet your needs; take a look at https://tiswww.case.edu/php/chet/bash/bashref.html#Modifying-Shell-Behavior for more information.
/ETC/INPUTRC
This file controls keyboard mappings, and the "readline" library (on which bash and other shells rely) uses this file to determine how keyboard input is handled.
We're going to create a somewhat generic file suitable for just about everyone:
# Allow the command prompt to wrap to the next line
set horizontal-scroll-mode Off
# Enable 8bit input
set meta-flag On
set input-meta On
# Turns off 8th bit stripping
set convert-meta Off
# Keep the 8th bit for display
set output-meta On
# none, visible or audible
set bell-style none
# All of the following map the escape sequence of the value
# contained in the 1st argument to the readline specific functions
"\eOd": backward-word
"\eOc": forward-word
# for linux console
"\e[1~": beginning-of-line
"\e[4~": end-of-line
"\e[5~": beginning-of-history
"\e[6~": end-of-history
"\e[3~": delete-char
"\e[2~": quoted-insert
# for xterm
"\eOH": beginning-of-line
"\eOF": end-of-line
# for Konsole
"\e[H": beginning-of-line
"\e[F": end-of-line
/ETC/SHELLS
This file contains a list of shells which can be used for the purposes of login. Each shell binary should be on its own line; we'll create this file with the following content:
/bin/sh
/bin/bash
/ETC/FSTAB
We'll create this file with the following entries. Note that your device names may be different than those listed here; be sure you indicate the proper device name to be used during the boot process, or your system won't boot.
For example, we've built our distribution on
/dev/sdb for most of this course. When we boot, however, it will be from a virtual machine with a single hard drive — so the device name will change to sda. Make sure your entries in fstab reflect the device names that will be present at boot./dev/sda3 / ext4 defaults 1 1
/dev/sda4 swap swap pri=1 0 0
/dev/sda2 /boot ext4 defaults 1 1
proc /proc proc nosuid,noexec,nodev 0 0
sysfs /sys sysfs nosuid,noexec,nodev 0 0
devpts /dev/pts devpts gid=5,mode=620 0 0
tmpfs /run tmpfs defaults 0 0
devtmpfs /dev devtmpfs mode=0755,nosuid 0 0
Note that we do not mount
/dev/sda1. That partition does not need to be mounted, and in fact, is best left unmounted.Building the Kernel
We downloaded the source for our kernel during stage 1. You may use a newer version of the kernel if it is available, but it is strongly recommended that you use source code from the stable branch.
For this course, we're using version 4.8.12 of the kernel source.
CONFIGURING THE KERNEL
Kernel configuration is a subject worthy of its own course here at Linux Academy. We cannot cover all of the configuration options in this course but we do cover general configuration. Keep in mind that building the kernel is fairly straightforward once our distro is up and running, so re-building the kernel at a later time is not difficult.
Cleaning the Kernel Source Tree
Change into the kernel source directory and issue:
make mrproper
Entering the Kernel Configuration Utility
A text-based menu-driven configuration program is used to select the kernel options; we enter this system by executing:
make menuconfig
Setting Specific Kernel Options
Be sure to set the following options:
devtmpfs
Device Drivers —\>
Generic Driver Options —\>
\* Maintain a devtmpfs filesystem to mount at /dev
DHCP Support
Networking Support —\>
Networking Options -\>
\<\*\> The IPv6 Protocol
BUILDING AND INSTALLING THE KERNEL
Once you've configured the kernel, save your configuration. Execute
make to build the kernel:make
Install the kernel modules:
make modules_install
NOTE: The
/boot partition must be mounted before the following steps are undertaken. Be sure of this.
Now we need to copy the kernel image to the
/boot directory:cp -v arch/x86/boot/bzImage /boot/vmlinuz-4.8.12
The same goes for the kernel symbols, which are stored in
System.map:cp -v System.map /boot/System.map-4.8.12
It's a good idea, as well, to copy the kernel configuration file itself:
cp -v .config /boot/config-4.8.12
Install the documentation:
install -d /usr/share/doc/linux-4.8.12
cp -r Documentation/* /usr/share/doc/linux-4.8.12
CONFIGURING LINUX MODULES
Now that we've got the kernel image installed, we need to tell the kernel how and in what order to load modules. For USB devices, specifically, we need to load modules in a specific order.
Create the
/etc/modprobe.d directory:install -v -m755 -d /etc/modprobe.d
And now, create a
usb.conf file in that directory with the following contents:install ohci_hcd /sbin/modprobe ehci_hcd ; /sbin/modprobe -i ohci_hcd ; true
install uhci_hcd /sbin/modprobe ehci_hcd ; /sbin/modprobe -i uhci_hcd ; true
Installing GRUB
For this video, we employ GRUB as a bootloader. We strongly encourage you to look at the "Bootloading with GRUB" video on the LinuxAcademy.com website, even if you're familiar with GRUB. It is very easy to misconfigure GRUB and end up with an unbootable system.
CREATING THE GRUB CONFIGURATION FILE
We'll create this file with the following content. Note that the value of the
set root command must be the /boot partition; the root= entry must specify the location of the / partition. Again, see the "Bootloading With GRUB" video if you do not understand what these things mean.set default=0
set timeout=10
insmod ext2 biosdisk
set root=(hd0,2)
menuentry "Linux 4.8.12" {
linux /boot/vmlinuz-4.8.12 root=/dev/sda2 ro
}
ADDING AN ENTRY TO AN EXISTING GRUB CONFIGURATION
If you want to add the new distribution to an existing grub configuration, simply add the "menu entry" from the configuration file above. You may have to run
grub-update or a similar command to actually update the bootloader.Logout and Reboot
We now want to reboot our system. First, let's logout:
logout
UNMOUNT VIRTUAL FILESYSTEMS
umount -v $BROOT/dev/pts
umount -v $BROOT/dev
umount -v $BROOT/run
umount -v $BROOT/proc
umount -v $BROOT/sys
UMOUNT OUR DESTINATION DRIVE
umount $BROOT/boot
umount $BROOT
NOW REBOOT
shutdown -rf now
The system should go down for reboot. If necessary, detach the destination drive and attach it to a new VM or re-configure your virtual machine (or hardware) as needed to boot.
TROUBLE
If your system doesn't boot, it's likely you have issues with GRUB. Remember to double-check your device names. Again, the "Bootloading With GRUB" video can be of great help when troubleshooting problems with the bootloader.
Final Thoughts
UPDATES
Updates to both the kernel and installed packages are a frequent occurrence. You will need to check monthly, if not weekly, for updates to the source. Updating the packages makes use of the same process by which the packages were built (
configure, make, make install) most of the time.ADDING ADDITIONAL SOFTWARE
Feel free to add additional software as needed. How you do this is entirely up to you — building from source is one option, but keep in mind that constantly rebuilding software from source to stay abreast of security updates and the like is a time-consuming activity.
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