How to create Linux Kernel Headers from Linux Kernel Source?
I’m working with Tiny Core Linux and attempting to install Vmware Tools, which of course needs the Kernel Headers :-). It does not appear they have the Kernel Headers readily available in a package, but they do have the kernel source. As a result I downloaded that source, and I’m attempting to create headers from it, but I have no clue what I’m doing. In the googling I ran into, it sounded like:
Might do what I need it to do, and this is in fact a proper make target, but it errors out on me with the following:
tc@box:/usr/src/linux-3.16.6$ make headers_install CHK include/generated/uapi/linux/version.h HOSTCC arch/x86/tools/relocs_32.o In file included from arch/x86/tools/relocs_32.c:1:0: arch/x86/tools/relocs.h:17:32: fatal error: tools/le_byteshift.h: No such file or directory #include ^ compilation terminated. scripts/Makefile.host:134: recipe for target 'arch/x86/tools/relocs_32.o' failed make[1]: *** [arch/x86/tools/relocs_32.o] Error 1 arch/x86/Makefile:181: recipe for target 'archscripts' failed make: *** [archscripts] Error 2 Am I on the right track here, and I’m just missing a dependency or something, or am I completely on the wrong track? Any pointers someone can give me on how to proceed next? It looks like «tools/le_byteshift.h» is somehow missing, but I’m not sure where to begin isolating what package that is even from to get this to work properly. How does one make the kernel headers from the source? Any pointers greatly appreciated!
Rand/eng works
Although relatively straightforward, compiling and selecting the Linux headers is too manual and is only partially explained at several different documents in the codebase. This entry provides some guidelines and also scripts to automate a bit the process. Find the complete script at the bottom.
Building
First of all, move to the list of kernel sources. Browse through it to find the desired version of the headers. You may download the sources and uncompress them into the disk. In this sample script the kernel 4.14.151 is used.
1 2 3 4 5 6 7 8 9 10 11 12 13header_version=4.14.151 header_dir=linux-$header_version> mkdir -p ~/linux-headers cd ~/linux-headers current=$PWD # Download sources if [[ ! -d $header_dir ]]; then wget https://cdn.kernel.org/pub/linux/kernel/v4.x/$header_dir.tar.gz tar xvzf $header_dir.tar.gz cd ~/linux-headers/$header_dir fiHave a look at the Documentation/process/changes.rst file to understand the expected versions of the third-party libraries required for the compilation. Follow the process manually, then head to Documentation/admin-guide/README.rst .
First, the configuration must be defined. In this example we don’t tailor anything, so it will take a considerable amount of space (not being accurate, you should probably make sure you have 10GB+ of available disk).
# Note: before continue, perform all checks on the versions for the packages cd ~/linux-headers/$header_dir # Create configuration file (here, a sample one; not tailored) ## Note: the kernel will be larger when using a sample configuration ## For instance, you may consider saving 10-15 GB for this cp /boot/config-$(uname -r) .configIt is now time to compile the headers and the kernel modules. The first command will prompt a lot of questions. After that, both commands will take a good amount of time to finish. In the example we are dedicating the full computing power (all the CPUs) to speed up the building process.
# Compile headers make -j$cores> # Compile kernel modules ## Note: "make -j$ would compile using all CPUs" sudo make -j$cores> modules_installInstalling
After the compilation it is now time to install the headers in the system and make them available for use. You may find issues with configurations such as the locales. Just fix it and retry as needed.
# Install headers ## Note: be sure to properly setup the locales to correct values ## (e.g., everything to "en_US.UTF-8" did work) sudo make -j$cores> install ## Note: after this, the kernel will be available under /lib/modulesEnabling
After the installation, the system must know that this kernel is available for booting.
# Enable it for booting sudo update-initramfs -c -k $header_version> sudo update-grubIf you would wish to select this version of the kernel for the next boot, you can either:
- Enable the GRUB menu and select it manually
- Modify manually the configuration flags under etc/default/grub , then set the flags as desired. For instance, set something like GRUB_DEFAULT=”Advanced options for Ubuntu>Ubuntu, with Linux 4.14.151”
- Use some tool like grub-customizer. This one is handy when your VM is not able to show the GRUB menu. When running it, move to the “General settings” tab, then choose “default entry > predefined” and pick the specific version from the list
The latter option can be installed and run as follows:
# Install grub-customizer sudo add-apt-repository ppa:danielrichter2007/grub-customizer apt-get update sudo apt-get install grub-customizer ## Note: only needed for the usage of grub-customizer when connecting by xterm sudo apt install x11-xserver-utils -y # Run it (will require X11 previously installed in the system) sudo grub-customizer
Altogether
All the script put together, for convenience. Note that this works for building kernel 4.14.151 on an Ubuntu 16.04.4 LTS.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103#!/bin/bash header_version=4.14.151 header_dir=linux-$header_version> cores=$(nproc --all) mkdir -p ~/linux-headers cd ~/linux-headers current=$PWD # Download sources if [[ ! -d $header_dir ]]; then wget https://cdn.kernel.org/pub/linux/kernel/v4.x/$header_dir.tar.gz tar xvzf $header_dir.tar.gz cd ~/linux-headers/$header_dir fi # Install make sudo apt install -y build-essential cd ~ # Install third-party requirements if [[ ! -d ~/mcelog ]]; then git clone git://git.kernel.org/pub/scm/utils/cpu/mce/mcelog.git cd mcelog make sudo make install fi cd $PWD # Install third-party requirements sudo apt install -y jfsutils reiserfsprogs xfsprogs btrfs-progs pcmciautils quota ppp nfs-common procps oprofile udev grub iptables openssl bc sudo apt install -y libelf-dev libssl-dev # Check versions to fit those in Documentation/process/changes.rst gcc --version make --version ld -v fdformat --version depmod -V e2fsck -V fsck.jfs -V fsck.jfs -V reiserfsck -V xfs_db -V mksquashfs -version dpkg -l | grep btrfsck pccardctl -V dpkg -l | grep quota pppd --version showmount --version ps --version dpkg -l | grep oprofile dpkg -l | grep udev grub --version || grub-install --version dpkg -l | grep mcelog iptables -V openssl version bc --version perl --version perldoc -l Getopt::Long perl -MGetopt::Long -le 'print $INC' perl -MGetopt::Std -le 'print $INC' perl -MFile::Basename -le 'print $INC' perl -MFile::Find -le 'print $INC' # Create configuration file (here, a sample one; not tailored) ## Note: the kernel will be larger when using a sample configuration ## For instance, you may consider saving 10-15 GB for this cd ~/linux-headers/$header_dir cp /boot/config-$(uname -r) .config df -h # Compile headers make -j$cores> # Compile kernel modules ## Note: "make -j$ would compile using all CPUs" sudo make -j$cores> modules_install # Install headers ## Note: be sure to properly setup the locales to correct values ## (e.g., everything to "en_US.UTF-8" did work) sudo make -j$cores> install ## Note: after this, the kernel will be available under /lib/modules df -h # Enable it for booting sudo update-initramfs -c -k $header_version> sudo update-grub # Install grub-customizer sudo add-apt-repository ppa:danielrichter2007/grub-customizer apt-get update sudo apt-get install grub-customizer ## Note: only needed for the usage of grub-customizer when connecting by xterm sudo apt install x11-xserver-utils -y # Run it (will require X11 previously installed in the system) sudo grub-customizer df -hExporting kernel headers for use by userspace¶
The "make headers_install" command exports the kernel's header files in a form suitable for use by userspace programs.
The linux kernel's exported header files describe the API for user space programs attempting to use kernel services. These kernel header files are used by the system's C library (such as glibc or uClibc) to define available system calls, as well as constants and structures to be used with these system calls. The C library's header files include the kernel header files from the "linux" subdirectory. The system's libc headers are usually installed at the default location /usr/include and the kernel headers in subdirectories under that (most notably /usr/include/linux and /usr/include/asm).
Kernel headers are backwards compatible, but not forwards compatible. This means that a program built against a C library using older kernel headers should run on a newer kernel (although it may not have access to new features), but a program built against newer kernel headers may not work on an older kernel.
The "make headers_install" command can be run in the top level directory of the kernel source code (or using a standard out-of-tree build). It takes two optional arguments:
make headers_install ARCH=i386 INSTALL_HDR_PATH=/usrARCH indicates which architecture to produce headers for, and defaults to the current architecture. The linux/asm directory of the exported kernel headers is platform-specific, to see a complete list of supported architectures use the command:
INSTALL_HDR_PATH indicates where to install the headers. It defaults to "./usr".
An 'include' directory is automatically created inside INSTALL_HDR_PATH and headers are installed in 'INSTALL_HDR_PATH/include'.
The kernel header export infrastructure is maintained by David Woodhouse .
Exporting kernel headers for use by userspace¶
The "make headers_install" command exports the kernel's header files in a form suitable for use by userspace programs.
The linux kernel's exported header files describe the API for user space programs attempting to use kernel services. These kernel header files are used by the system's C library (such as glibc or uClibc) to define available system calls, as well as constants and structures to be used with these system calls. The C library's header files include the kernel header files from the "linux" subdirectory. The system's libc headers are usually installed at the default location /usr/include and the kernel headers in subdirectories under that (most notably /usr/include/linux and /usr/include/asm).
Kernel headers are backwards compatible, but not forwards compatible. This means that a program built against a C library using older kernel headers should run on a newer kernel (although it may not have access to new features), but a program built against newer kernel headers may not work on an older kernel.
The "make headers_install" command can be run in the top level directory of the kernel source code (or using a standard out-of-tree build). It takes two optional arguments:
make headers_install ARCH=i386 INSTALL_HDR_PATH=/usrARCH indicates which architecture to produce headers for, and defaults to the current architecture. The linux/asm directory of the exported kernel headers is platform-specific, to see a complete list of supported architectures use the command:
INSTALL_HDR_PATH indicates where to install the headers. It defaults to "./usr".
An 'include' directory is automatically created inside INSTALL_HDR_PATH and headers are installed in 'INSTALL_HDR_PATH/include'.
The kernel header export infrastructure is maintained by David Woodhouse .