Lakka-LibreELEC/packages/readme.md

Structure of package.mk files

Introduction

The package.mk file defines variables and functions to build a package.

Variables

To control the build behaviour of your package, use variables in the top-down order listed here.

Base

Variable	Default	Required	Description
PKG_NAME	-	yes	Name of the packaged software application. Should be lowercase
PKG_VERSION	-	yes	Version of the packaged software application. If the version is a githash, please use the full githash, not the abbreviated form.
PKG_SHA256	-	yes	SHA256 hashsum of the application download file
PKG_ARCH	any	no	Architectures for which the package builds. any or a space separated list of aarch64, arm or x86_64
PKG_LICENSE	-	yes	License of the software application. Reference
PKG_SITE	-	yes	Site of the software application
PKG_URL	-	yes	Address at which the source of the software application can be retrieved
PKG_MAINTAINER	-	no	Your name
PKG_DEPENDS_BOOTSTRAP PKG_DEPENDS_HOST PKG_DEPENDS_INIT PKG_DEPENDS_TARGET	-	no	A space separated list of name of packages required to build the software application
PKG_SECTION	-	no	virtual if the package only defines dependencies
PKG_SHORTDESC	-	no yes for addons	Short description of the software package
PKG_LONGDESC	-	yes	Long description of the package including purpose or function within LibreELEC or Kodi

Universal Build Option

Variable	Default	Required	Description
PKG_SOURCE_DIR	-	no	Force the folder name that application sources are unpacked to. Used when sources do not automatically unpack to a folder with the PKG_NAME-PKG_VERSION naming convention.
PKG_TAR_STRIP_COMPONENTS	-	no	When this option is set the top level directory is not get stripped off while extracting an archive.
PKG_SOURCE_NAME	-	no	Force the filename of the application sources. Used when the filename is not the basename of PKG_URL
PKG_PATCH_DIRS	-	no	Patches in ./patches are automatically applied after package unpack. Use this option to include patches from an additional folder, e.g. ./patches/$PKG_PATCH_DIRS
PKG_NEED_UNPACK	-	no	Space separated list of files or folders to include in package stamp calculation. If the stamp is invalidated through changes to package files or dependent files/folders the package is cleaned and rebuilt. e.g. PKG_NEED_UNPACK="$(get_pkg_directory linux)" will trigger clean/rebuild of a Linux kernel driver package when a change to the linux kernel package is detected.
PKG_TOOLCHAIN	auto	no	Control which build toolchain is used. For detailed information, see reference.
PKG_BUILD_FLAGS	-	no	A space separated list of flags with which to fine-tune the build process. Flags can be enabled or disabled with a + or - prefix. For detailed information, see the Reference.
PKG_PYTHON_VERSION	python3.8	no	Define the Python version to be used.
PKG_IS_KERNEL_PKG	-	no	Set to yes for packages that include Linux kernel modules
PKG_DEPENDS_CONFIG	-	no	Space separated list of packages to add to PKG_CONFIG_PATH. Use this to build with support for -sysroot packages (See [reference](BUILD_FLAGS options).

Meson Options

Variable	Default	Required	Description
PKG_MESON_SCRIPT	$PKG_BUILD/meson.build	no	Meson build file to use
PKG_MESON_OPTS_TARGET	-	no	Options directly passed to meson

CMAKE Options

Variable	Default	Required	Description
PKG_CMAKE_SCRIPT	$PKG_BUILD/CMakeLists.txt	no	CMake build file to use
PKG_CMAKE_OPTS_HOST PKG_CMAKE_OPTS_TARGET	-	no	Options directly passed to cmake

Configure Options

Variable	Default	Required	Description
PKG_CONFIGURE_SCRIPT	$PKG_BUILD/configure	no	configure script to use
PKG_CONFIGURE_OPTS PKG_CONFIGURE_OPTS_BOOTSTRAP PKG_CONFIGURE_OPTS_HOST PKG_CONFIGURE_OPTS_INIT PKG_CONFIGURE_OPTS_TARGET	-	no	Options directly passed to configure

Make Options

Variable	Default	Required	Description
PKG_MAKE_OPTS PKG_MAKE_OPTS_BOOTSTRP PKG_MAKE_OPTS_HOST PKG_MAKE_OPTS_INIT PKG_MAKE_OPTS_TARGET	-	no	Options directly passed to make in the build step
PKG_MAKEINSTALL_OPTS_HOST PKG_MAKEINSTALL_OPTS_TARGET	-	no	Options directly passed to make in the install step

Addons

Additional options used when the package builds an addon.

Variable	Default	Required	Description
PKG_REV	-	yes	The revision number of the addon (starts at 100). Must be placed after PKG_VERSION. Must be incremented for each new version else Kodi clients will not detect version change and download the updated addon.
PKG_IS_ADDON	no	yes	Must be set to yes or to embedded when this addon is part of the image
PKG_ADDON_NAME	-	yes	Proper name of the addon that is shown at the repo
PKG_ADDON_TYPE	-	yes	See LE/config/addon/ for other possibilities
PKG_ADDON_VERSION	-	no	The version of the addon, used in addon.xml
PKG_ADDON_PROVIDES	-	no	Provides in addon-xml
PKG_ADDON_REQUIRES	-	no	Requires used in addon.xml
PKG_ADDON_PROJECTS	@PROJECTS@	no	for available projects or devices, see projects subdirectory (note: Use RPi for RPi project, and RPi1 for RPi device)
PKG_DISCLAIMER	-	no	Disclaimer in addon-xml
PKG_ADDON_IS_STANDALONE	-	no	Defines if an addon depends on Kodi (on) or is standalone (yes)
PKG_ADDON_BROKEN	-	no	Marks an addon as broken for the user

Detailed Information for Options

TOOLCHAIN options

Application/packages needs different toolchains for build. For instance cmake or the classic ./configure or same very different.

For the most application/packages, the auto-detection of the toolchain works proper. But not always. To select a specific toolchain, you only need to set the PKG_TOOLCHAIN variable.

Toolchain	Description (if needed)
meson	Meson Build System
cmake	CMake with Ninja
cmake-make	CMake with Make
autotools	GNU Build System
configure	preconfigured GNU Build System
ninja	Ninja Build
make	Makefile Based
manual	only runs self writen build steps, see Functions

Auto-Detection

The auto-detections looks for specific files in the source path.

1. meson.build (PKG_MESON_SCRIPT) => meson toolchain
2. CMakeLists.txt (PKG_CMAKE_SCRIPT) => cmake toolchain
3. configure (PKG_CONFIGURE_SCRIPT) => configure toolchain
4. Makefile => make toolchain

When none of these was found, the build abort and you have to set the toolchain via PKG_TOOLCHAIN

BUILD_FLAGS options

Build flags implement often used build options. Normally these are activated be default, but single applications/packages has problems to compile/run with these.

Set the variable PKG_BUILD_FLAGS in the package.mk to enable/disable the single flags. It is a space separated list. The flags can enabled with a + prefix, and disabled with a -.

flag	default	affected stage(s)	description
pic	disabled	target, init	Position Independent Code
pic:host	disabled	host, bootstrap	see above
speed	disabled	target, init	replaces default -O2 compiler optimization with -O3 (can only enable; overrules size)
size	disabled	target, init	replaces default -O2 compiler optimization with -Os (can only enable)
lto	disabled	target, init	enable LTO (Link Time optimization) in the compiler and linker unless disabled via LTO_SUPPORT. Compiles non-fat LTO objects (only bytecode) and performs single-threaded optimization at link stage
lto-parallel	disabled	target, init	same as lto but enables parallel optimization at link stage. Only enable this if the package build doesn't run multiple linkers in parallel otherwise this can result in lots of parallel processes!
lto-fat	disabled	target, init	same as lto but compile fat LTO objects (bytecode plus optimized assembly). This increases compile time but can be useful to create static libraries suitable both for LTO and non-LTO linking
lto-off	disabled	target, init	explicitly disable LTO in the compiler and linker
bfd	-	target, init	+bfd prefers bfd linker over default linker, -bfd disables using bfd
gold	-	target, init	+gold prefers gold linker over default linker, -gold disables using gold
mold	-	target, init	+mold prefers mold linker over default linker, -mold disables using gold
parallel	enabled	all	make or ninja builds with multiple threads/processes (or not)
strip	enabled	target	strips executables (or not)
sysroot	enabled	target	installs the package to the sysroot folder (or not)
local-cc	disabled	host	use compiler from buildhost instead of host-gcc/g++ in toolchain

Example

PKG_BUILD_FLAGS="+pic -gold"
PKG_BUILD_FLAGS="-parallel"

Functions

All build steps in the LibreELEC build system are done by shell function. These functions can be overwritten in the package.mk. However, this raises problems when the build system is updated. To reduce the impact, most functions are extended by pre_ and post_ scripts to use instead.

When it is nesseary to replace configure, make and makeinstall, please use PKG_TOOLCHAIN="manual".

Some of the build steps needs to be run once, like unpack. Other steps needs to be run multiple times, to create the toolchain (stage bootstrap & host) or to create the LE image (stage init & target). These stage specific functions have the stage as suffix, like make_target.

Full list of overwrittable functions.

function	stages specific	description
configure_package	-	Optional function to implement late binding variable assignment (see below)
unpack pre_unpack post_unpack	-	Extract the source from the downloaded file
pre_patch post_patch	-	Apply the patches to the source, after extraction. The patch function it self is not allowed to overwritten
pre_build_[stage]	yes	Runs before of the start of the build
pre_configure pre_configure_[stage] configure_[stage] post_configure_[stage]	yes	Configure the package for the compile. This is only relevant for toolchain, that supports it (e.g. meson, cmake, configure, manual)
make_[stage] pre_make_[stage] post_make_[stage]	yes	Build of the package
makeinstall_[stage] pre_makeinstall_[stage] post_makeinstall_[stage]	yes	Installation of the files in the correct pathes host: TOOLCHAIN target: SYSROOT and IMAGE bootstrap and init: temporary destination
addon	-	Copy all files together for addon creation. This is requiered for addons
post_install_addon	-	Post processing of installed addon files in ${INSTALL} directory

Directory structure

Every package has its own set of build and install directories. The sources are extracted and built in the former, and build artifacts are installed to the latter. Usually an install target provided by the package build system will populate the install directory automatically, but it's important that you use the standard usr/lib/, usr/bin/ etc. structure when doing so manually, because the contents of the install directory will be part of the final image (with the exception of top level hidden directories).

Sometimes it's necessary to access build artifacts from different packages - like an addon collecting files of various other packages. In that case you need to access the files using the package's install directories (and not their build directories since they might not exist anymore). If you need additional files which should not be part of the final image, you can use a hidden directory for those - grep for .noinstall for some examples.

Late Binding variable assignment

A package will be loaded only once, by the call to config/options. During this process, additional package specific variables will be initialised, such as:

• PKG_BUILD - path to the build folder
• PKG_SOURCE_NAME - if not already specified, generated from PKG_URL, PKG_NAME and PKG_VERSION

Since these variables will not exist at the time the package is loaded, they can only be referenced after package has loaded. This can be accomplished by referencing these variables in the configure_package() function which is executed once the additional variables have been assigned.

If necessary, the following variables would be configured in configure_package() as they are normally relative to ${PKG_BUILD}:

  PKG_CONFIGURE_SCRIPT
  PKG_CMAKE_SCRIPT
  PKG_MESON_SCRIPT

Further to this, toolchain variables that are defined in setup_toolchain() must not be referenced "globally" in the package as they will only be configured reliably after setup_toolchain() has been called during scripts/build. Any variable in the following list must instead be referenced in a package function such as pre_build_*, pre_configure_*, pre_make_* etc.:

  TARGET_CFLAGS TARGET_CXXFLAGS TARGET_LDFLAGS
  NINJA_OPTS MAKEFLAGS
  DESTIMAGE
  CC CXX CPP LD
  AS AR NM RANLIB
  OBJCOPY OBJDUMP
  STRIP
  CPPFLAGS CFLAGS CXXFLAGS LDFLAGS
  PKG_CONFIG
  PKG_CONFIG_PATH
  PKG_CONFIG_LIBDIR
  PKG_CONFIG_SYSROOT_DIR
  PKG_CONFIG_ALLOW_SYSTEM_CFLAGS
  PKG_CONFIG_ALLOW_SYSTEM_LIBS
  CMAKE_CONF CMAKE
  HOST_CC HOST_CXX HOSTCC HOSTCXX
  CC_FOR_BUILD CXX_FOR_BUILD BUILD_CC BUILD_CXX
  _python_sysroot _python_prefix _python_exec_prefix

Lastly, the following variables are assigned during scripts/build but some packages may need to use alternative values for these variables. To do so, the package must assign alternative values in pre_build_*/pre_configure_*/pre_make_* etc. functions as these functions will be called after the variables are initialised with default values in scripts/build but before they are used by scripts/build.

  CMAKE_GENERATOR_NINJA

  TARGET_CONFIGURE_OPTS
  TARGET_CMAKE_OPTS
  TARGET_MESON_OPTS

  HOST_CONFIGURE_OPTS
  HOST_CMAKE_OPTS
  HOST_MESON_OPTS

  INIT_CONFIGURE_OPTS
  INIT_CMAKE_OPTS
  INIT_MESON_OPTS

  BOOTSTRAP_CONFIGURE_OPTS
  BOOTSTRAP_CMAKE_OPTS
  BOOTSTRAP_MESON_OPTS

Example

configure_package() {
  # now we know where we're building, assign a value
  PKG_CONFIGURE_SCRIPT="${PKG_BUILD}/gettext-tools/configure"
}

post_patch() {
  # replace hardcoded stuff
  sed -i ${PKG_CONFIGURE_SCRIPT} 's|hardcoded stuff|variable stuff|'
}

pre_configure_target() {
  # add extra flag to toolchain default
  CFLAGS="$CFLAGS -DEXTRA_FLAG=yeah"
}

post_makeinstall_target() {
  # remove unused executable, install what remains
  rm $INSTALL/usr/bin/bigexecutable
}

tools/pkgcheck

Use tools/pkgcheck to verify packages. It detects the following issues:

Issue	Level	Meaning
late binding violation	FAIL	Late binding variables referenced outside of a function - see late binding
duplicate function def	FAIL	Function defined multiple times, only last definition will be used
bad func - missing brace	FAIL	Opening brace ({) for function definition should be on same line as the function def, ie. pre_configure_target() {
intertwined vars & funcs	WARN	Variable assignments and logic is intertwined with functions - this is cosmetic, but variables and logic should be specified before all functions
unknown function	WARN	Could be a misspelled function, ie. per_configure_target() { which might fail silently.
ignored depends assign	WARN	Values assigned to PKG_DEPENDS_* outside of the global section or configure_package() will be ignored.

Add a new package to the Image

1. Think about, why you need it in the image.
   • new multimedia tool
   • add a new network tool
   • new kernel driver
   • ...
2. Find a place in the packages tree
   • look into the package tree structure, which is generally self explaind.
   • do not place it in an existing package (directory that includes a package.mk)
   • when you found a place, create a directory with the name of your package (use same value for PKG_NAME!!)
3. Create an initial package.mk
   • you can find a template under packages/package.mk.template. Copy the template into the new directory and call it package.mk
   • apply any required changes to your new package.mk
4. Find a place in the dependency tree
   • when it extend an existing package, add it there to the PKG_DEPENDS_TARGET/PKG_DEPENDS_HOST etc.
   • take a look into the path packages/virtual, there you should find a virtual packages, that match your new package (misc-packages should be the last option)
5. Now you can build your image
   • after the build, inside the BUILD_DIR (normally build.*) folder you should find a directory with your package name and -version, eg. widget-1.2.3.

Example

# SPDX-License-Identifier: GPL-2.0
# Copyright (C) 2018-present Team LibreELEC (https://libreelec.tv)

PKG_NAME="mariadb-connector-c"
PKG_VERSION="3.0.2"
PKG_SHA256="f44f436fc35e081db3a56516de9e3bb11ae96838e75d58910be28ddd2bc56d88"
PKG_LICENSE="LGPL"
PKG_SITE="https://mariadb.org/"
PKG_URL="https://github.com/MariaDB/mariadb-connector-c/archive/v$PKG_VERSION.tar.gz"
PKG_DEPENDS_TARGET="toolchain zlib openssl"
PKG_LONGDESC="mariadb-connector: library to conntect to mariadb/mysql database server"
PKG_BUILD_FLAGS="-gold"

PKG_CMAKE_OPTS_TARGET="-DWITH_EXTERNAL_ZLIB=ON \
                       -DAUTH_CLEARTEXT=STATIC \
                       -DAUTH_DIALOG=STATIC \
                       -DAUTH_OLDPASSWORD=STATIC \
                       -DREMOTEIO=OFF"

post_makeinstall_target() {
  # drop all unneeded
  rm -rf $INSTALL/usr
}