Edit
kc3-lang/freetype/docs/INSTALL.CROSS
Alexei Podtelezhnikov
- docs/INSTALL.CROSS
-
This document contains instructions on how to cross-build the FreeType library on Unix systems, for example, building binaries for Linux/MIPS on FreeBSD/i386. Before reading this document, please consult the file `INSTALL.UNIX' for required tools and the basic self-building procedure. 1. Required Tools ----------------- For self-building the FreeType library on a Unix system, GNU Make 3.81 or newer is required. `INSTALL.UNIX' contains hints how to check the installed `make'. The GNU C compiler to cross-build the target system is required. Currently, using a non-GNU cross compiler is untested. The cross compiler is expected to be installed with a system prefix. For example, if your building system is FreeBSD/i386 and the target system is Linux/MIPS, the cross compiler should be installed with the name `mips-ip22-linuxelf-gcc'. A C compiler for a self-build is required also, to build a tool (`apinames') that is executed during the build procedure. Non-GNU self compilers are acceptable, but such a setup is untested. 2. Configuration ---------------- 2.1. Building and target system To configure a cross-build, the options `--host=<system>' and `--build=<system>' must be passed to the `configure' script. For example, if your build system is FreeBSD/i386 and the target system is Linux/MIPS, say ./configure \ --build=i386-unknown-freebsd \ --host=mips-ip22-linuxelf \ [other options] It should be noted that `--host=<system>' specifies the system where the built binaries will be executed, not the system where the build actually happens. Older versions of GNU autoconf use the option pair `--host=' and `--target='. This is broken and doesn't work. Similarly, an explicit CC specification like env CC=mips-ip22-linux-gcc ./configure # BAD or env CC=/usr/local/mips-ip22-linux/bin/gcc ./configure # BAD doesn't work either; such a configuration confuses the `configure' script while trying to find the cross and native C compilers. 2.2. The prefix to install FreeType2 Setting `--prefix=<prefix>' properly is important. The prefix to install FreeType2 is written into the `freetype-config' script and `freetype2.pc' configuration file. If the built FreeType 2 library is used as a part of the cross-building system, the prefix is expected to be different from the self-building system. For example, a configuration with `--prefix=/usr/local' installs binaries into the system-wide `/usr/local' directory, which then can't be executed due to the incorrect architecture. This causes confusion in configuration of all applications that use FreeType2. Instead, use a prefix to install the cross-build into a separate system tree, for example, `--prefix=/usr/local/mips-ip22-linux/'. On the other hand, if the built FreeType 2 library is used as a part of the target system, the prefix to install should reflect the file system structure of the target system. 2.3. Library dependencies FreeType normally depends on external libraries like `libpng' or `libharfbuzz'. The easiest case is to deactivate all such dependencies using the `--without-XXX' configuration options. However, if you want to use those libraries, you should ensure that they are available both on the target system and as (cross-compiled) libraries on the build system. FreeType uses `pkg-config' to find most of the libraries; the other libraries it links to are expected in the standard system directories. Since the default pkg-config's meta-information files (like `harfbuzz.pc') of the build platform don't work, use one of the two possible solutions below. o Use pkg-config's meta-information files that are adjusted to cross-compile and cross-link with the target platform's libraries. Make sure those files are found before the build system's default files. Example: ./configure \ --build=i386-unknown-freebsd \ --host=mips-ip22-linuxelf \ PKG_CONFIG_LIBDIR="/usr/local/mips-ip22-linux/lib/pkgconfig" \ [other options] See the manpage of `pkg-config' for more details. o Set variables like LIBPNG_LIBS as additional options to the `configure' script, overriding the values `pkg-config' would provide. `configure --help' shows the available environment variables. Example: ./configure \ --build=i386-unknown-freebsd \ --host=mips-ip22-linuxelf \ LIBPNG_CFLAGS="-I/usr/local/mips-ip22-linux/include" \ LIBPNG_LIBS="-L/usr/local/mips-ip22-linux/lib -lpng12" \ [other options] 3. Building command ------------------- If the configuration finishes successfully, invoking GNU make builds FreeType2. Just say make or gmake depending on the name the GNU make binary actually has. 4. Installation --------------- Saying make install as usual to install FreeType2 into the directory tree specified by the argument of the `--prefix' option. As noted in section 2.2, FreeType2 is sometimes configured to be installed into the system directory of the target system, and should not be installed in the cross-building system. In such cases, the make variable `DESTDIR' is useful to change the root directory in the installation. For example, after make DESTDIR=/mnt/target_system_root/ install the built FreeType2 library files are installed into the directory `/mnt/target_system_root/<prefix_in_configure>/lib'. 5. TODO ------- Cross building between Cygwin (or MSys) and Unix must be tested. ---------------------------------------------------------------------- Copyright (C) 2006-2024 by suzuki toshiya, David Turner, Robert Wilhelm, and Werner Lemberg. This file is part of the FreeType project, and may only be used, modified, and distributed under the terms of the FreeType project license, LICENSE.TXT. By continuing to use, modify, or distribute this file you indicate that you have read the license and understand and accept it fully. --- end of INSTALL.CROSS ---