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diff --git a/xcomp/README.md b/xcomp/README.md new file mode 100644 index 0000000000..e97b26e605 --- /dev/null +++ b/xcomp/README.md @@ -0,0 +1,485 @@ +Cross Compiling Erlang/OTP +========================== + +This document describes how to cross compile Erlang/OTP. Note that the support +for cross compiling Erlang/OTP is in its early stage of development, and +should be considered as experimental. You are encouraged to read the whole +document before attempting to cross compile Erlang/OTP. + +Building Erlang/OTP can be done either by using the `$ERL_TOP/otp_build` +script, or by invoking `$ERL_TOP/configure` and `make` directly (where +`$ERL_TOP` is the top directory in the source tree). Building using `otp_build` +is easier since it involves fewer steps, but the `otp_build` build procedure +is not as flexible as the `configure`/`make` build procedure. The binary +releases that we deliver are built using `otp_build`. Also note that +`otp_build configure` will produce a default configuration that differs from +what `configure` will produce by default. For example, currently +`--disable-dynamic-ssl-lib` is added to the `configure` command line arguments +unless `--enable-dynamic-ssl-lib` has been explicitly passed. The defaults +used by `otp_build configure` may change at any time without prior notice. + +The `$ERL_TOP/xcomp/erl-xcomp.conf.template` file contains all available cross +configuration variables and can be used as a template when creating a cross +compilation configuration. For examples of working cross configurations see +the `$ERL_TOP/xcomp/erl-xcomp-TileraMDE2.0-tilepro.conf` file and the +`$ERL_TOP/xcomp/erl-xcomp-x86_64-saf-linux-gnu.conf` file. If the default +behavior of a variable is satisfactory, the variable does not need to be set. +However, the `configure` script will issue a warning when a default value is +used. When a variable has been set, no warning will be issued. + +A cross configuration file can be passed to `otp_build configure` using the +`--xcomp-conf` command line argument. Note that `configure` does not accept +this command line argument. When using the `configure` script directly, pass +the configuration variables as arguments to `configure` using a +`<VARIABLE>=<VALUE>` syntax. Variables can also be passed as environment +variables to `configure`. However, if you pass the configuration in the +environment, make sure to unset all of these environment variables before +invoking `make`; otherwise, the environment variables might set make variables +in some applications, or parts of some applications, and you may end up with +an erroneously configured build. + +All Erlang/OTP applications except the `wx` application can be cross compiled. +The build of the `wx` driver will currently be automatically disabled when +cross compiling. + +The build system, including cross compilation configuration variables used, +may be subject to non backward compatible changes without prior notice. +Current cross build system has been tested when cross compiling some Linux/GNU +systems, but has only been partly tested for more esoteric platforms. The +VxWorks example file is highly dependent on our environment and is here more +or less only for internal use. + +Please submit any patches for cross compiling in a way consistent with this +system. All input is welcome as we have a very limited set of cross compiling +environments to test with. If a new configuration variable is needed, add it +to `$ERL_TOP/xcomp/erl-xcomp.conf.template`, and use it in `configure.in`. +Other files that might need to be updated are: + +- `$ERL_TOP/xcomp/erl-xcomp-vars.sh` +- `$ERL_TOP/erl-build-tool-vars.sh` +- `$ERL_TOP/erts/aclocal.m4` +- `$ERL_TOP/xcomp/README` +- `$ERL_TOP/xcomp/erl-xcomp-*.conf` + +Note that this might be an incomplete list of files that need to be updated. + +General information on how to submit patches can be found at: + <http://wiki.github.com/erlang/otp/submitting-patches> + +If you are building in a `git` working directory, the `configure` scripts need +to be generated before you can start building. This is done by invoking +`./otp_build autoconf` in the `$ERL_TOP` directory. The `configure` scripts +also have to be regenerated when a `configure.in` or `aclocal.m4` file is +modified. Note that this is *not* needed when building an unmodified version +of the released source. + +Build and Install +----------------- + + [1] + +Change directory into the top directory of the Erlang/OTP source tree. + + $ cd $ERL_TOP + +### Build ### + +In order to compile Erlang code, a small Erlang bootstrap system has to be +built, or an Erlang/OTP system of the same release as the one being built +has to be provided in the `$PATH`. The Erlang/OTP for the target system will +be built using this Erlang system, together with the cross compilation tools +provided. + +If you want to build using a compatible Erlang/OTP system in the `$PATH`, +jump to [3]. + +#### Building a Bootstrap System #### + + [2] + + $ ./configure --enable-bootstrap-only + $ make + +The `--enable-bootstrap-only` argument to `configure` isn't strictly necessary, +but will speed things up. It will only run `configure` in applications +necessary for the bootstrap, and will disable a lot of things not needed by +the bootstrap system. If you run `configure` without `--enable-boostrap-only` +you also have to run make as `make bootstrap`; otherwise, the whole system will +be built. + +#### Cross Building the System #### + + [3] + + $ ./configure --host=<HOST> --build=<BUILD> [Other Config Args] + $ make + +`<HOST>` is the host/target system that you build for. It does not have to be +a full `CPU-VENDOR-OS` triplet, but can be. The full `CPU-VENDOR-OS` triplet +will be created by executing `$ERL_TOP/erts/autoconf/config.sub <HOST>`. If +`config.sub` fails, you need to be more specific. + +`<BUILD>` should equal the `CPU-VENDOR-OS` triplet of the system that you +build on. If you execute `$ERL_TOP/erts/autoconf/config.guess`, it will in +most cases print the triplet you want to use for this. + +Pass the cross compilation variables as command line arguments to `configure` +using a `<VARIABLE>=<VALUE>` syntax. Note that you can *not* pass a +configuration file using `--xcomp-conf=<FILE>` when you invoke `configure` +directly. The `--xcomp-conf=<FILE>` argument can only be passed to +`otp_build configure`. + +`make` will verify that the Erlang/OTP system used when building is of the +same release as the system being built, and will fail if this is not the case. +It is possible, however not recommended, to force the cross compilation even +though the wrong Erlang/OTP system is used. This by invoking `make` like this: +`make ERL_XCOMP_FORCE_DIFFERENT_OTP=yes`. Note that this build might fail, +silently produce suboptimal code, or silently produce erroneous code. + +#### Installing #### + +You can either install using the installation paths determined by `configure` +[4], or install manually using [5]. + + [4] + + $ make install DESTDIR=<TEMPORARY_PREFIX> + +`make install` will install at a location specified when doing `configure`. +`configure` arguments specifying where the installation should reside are for +example: `--prefix`, `--exec-prefix`, `--libdir`, `--bindir`, etc. By default +it will install under `/usr/local`. You typically do not want to install your +cross build under `/usr/local` on your build machine. Using `DESTDIR` will +cause the installation paths to be prefixed by `$DESTDIR`. This makes it +possible to install and package the installation on the build machine without +having to place the installation in the same directory on the build machine as +it should be executed from on the target machine. + +When `make install` has finished, change directory into `$DESTDIR`, package +the system, move it to the target machine, and unpack it. Note that the +installation will only be working on the target machine at the location +determined by `configure`. + +Installing manually: + + [5] + + $ make release RELEASE_ROOT=<RELEASE_DIR> + +`make release` will copy what you have built for the target machine to +`<RELEASE_DIR>`. The `Install` script will not be run. The content of +`<RELEASE_DIR>` is what by default ends up in `/usr/local/lib/erlang`. + +The `Install` script used when installing Erlang/OTP requires common Unix +tools such as `sed` to be present in your `$PATH`. If your target system +does not have such tools, you need to run the `Install` script on your +build machine before packaging Erlang/OTP. The `Install` script should +currently be invoked as follows in the directory where it resides +(the top directory): + + $ ./Install [-cross] [-minimal|-sasl] <ERL_ROOT> + +where: + + * `-minimal` - Creates an installation that starts up a minimal + amount of applications, i.e., only `kernel` and + `stdlib` are started. The minimal system is normally + enough, and is what `make install` uses. + * `-sasl` - Creates an installation that also starts up the + `sasl` application. + * `-cross` - For cross compilation. Informs the install script + that it is run on the build machine. + * `<ERL_ROOT>` - The absolute path to the Erlang installation to use + at run time. This is often the same as the current + working directory, but does not have to be. It can + follow any other path through the file system to the + same directory. + +If neither `-minimal`, nor `-sasl` is passed as argument you will be +prompted. + +You can now either do [6] or [7]: + + [6] + +Decide where the installation should be located on the target machine, run +the `Install` script on the build machine, and package the installed +installation. The installation just need to be unpacked at the right location +on the target machine: + + $ cd <RELEASE_DIR> + $ ./Install -cross [-minimal|-sasl] <ABSOLUTE_INSTALL_DIR_ON_TARGET> + + [7] + +Package the installation in <RELEASE_DIR>, place it wherever you want on your +target machine, and run the `Install` script on your target machine: + + $ cd <ABSOLUTE_INSTALL_DIR_ON_TARGET> + $ ./Install [-minimal|-sasl] <ABSOLUTE_INSTALL_DIR_ON_TARGET> + +#### Building With the `otp_build` Script #### + + [8] + + $ cd $ERL_TOP + + [9] + + $ ./otp_build configure --xcomp-conf=<FILE> [Other Config Args] + +alternatively: + + $ ./otp_build configure --host=<HOST> --build=<BUILD> [Other Config Args] + +If you have your cross compilation configuration in a file, pass it using the +`--xcomp-conf=<FILE>` command line argument. If not, pass `--host=<HOST>`, +`--build=<BUILD>`, and the configuration variables using a `<VARIABLE>=<VALUE>` +syntax on the command line (same as in [3]). Note that `<HOST>` and `<BUILD>` +have to be passed one way or the other; either by using `erl_xcomp_host=<HOST>` +and `erl_xcomp_build=<BUILD>` in the configuration file, or by using the +`--host=<HOST>`, and `--build=<BUILD>` command line arguments. + +`otp_build configure` will configure both for the boostrap system on the +build machine and the cross host system. + + [10] + + $ ./otp_build boot -a + +`otp_build boot -a` will first build a bootstrap system for the build machine +and then do the cross build of the system. + + [11] + + $ ./otp_build release -a <RELEASE_DIR> + +`otp_build release -a` will do the same as [5], and you will after this have +to do a manual install either by doing [6], or [7]. + +Currently Used Configuration Variables +-------------------------------------- + +Note that you cannot define arbitrary variables in a cross compilation +configuration file. Only the ones listed below will be guaranteed to be +visible throughout the whole execution of all `configure` scripts. Other +variables needs to be defined as arguments to `configure` or exported in +the environment. + +### Variables for `otp_build` Only ### + +Variables in this section are only used, when configuring Erlang/OTP for +cross compilation using `$ERL_TOP/otp_build configure`. + +*NOTE*! These variables currently have *no* effect if you configure using +the `configure` script directly. + +* `erl_xcomp_build` - The build system used. This value will be passed as + `--build=$erl_xcomp_build` argument to the `configure` script. It does + not have to be a full `CPU-VENDOR-OS` triplet, but can be. The full + `CPU-VENDOR-OS` triplet will be created by + `$ERL_TOP/erts/autoconf/config.sub $erl_xcomp_build`. + If set to `guess`, the build system will be guessed using + `$ERL_TOP/erts/autoconf/config.guess`. + +* `erl_xcomp_host` - Cross host/target system to build for. This value will + be passed as `--host=$erl_xcomp_host` argument to the `configure` script. + It does not have to be a full `CPU-VENDOR-OS` triplet, but can be. The + full `CPU-VENDOR-OS` triplet will be created by: + `$ERL_TOP/erts/autoconf/config.sub $erl_xcomp_host` + +* `erl_xcomp_configure_flags` - Extra configure flags to pass to the + `configure` script. + +### Cross Compiler and Other Tools ### + +If the cross compilation tools are prefixed by `<HOST>-` you probably do +not need to set these variables (where `<HOST>` is what has been passed as +`--host=<HOST>` argument to `configure`). + +All variables in this section can also be used when native compiling. + +* `CC` - C compiler. + +* `CFLAGS` - C compiler flags. + +* `STATIC_CFLAGS` - Static C compiler flags. + +* `CFLAG_RUNTIME_LIBRARY_PATH` - This flag should set runtime library + search path for the shared libraries. Note that this actually is a + linker flag, but it needs to be passed via the compiler. + +* `CPP` - C pre-processor. + +* `CPPFLAGS` - C pre-processor flags. + +* `CXX` - C++ compiler. + +* `CXXFLAGS` - C++ compiler flags. + +* `LD` - Linker. + +* `LDFLAGS` - Linker flags. + +* `LIBS` - Libraries. + +#### *D*ynamic *E*rlang *D*river Linking #### + +*NOTE*! Either set all or none of the `DED_LD*` variables. + +* `DED_LD` - Linker for Dynamically loaded Erlang Drivers. + +* `DED_LDFLAGS` - Linker flags to use with `DED_LD`. + +* `DED_LD_FLAG_RUNTIME_LIBRARY_PATH` - This flag should set runtime library + search path for shared libraries when linking with `DED_LD`. + +#### Large File Support #### + +*NOTE*! Either set all or none of the `LFS_*` variables. + +* `LFS_CFLAGS` - Large file support C compiler flags. + +* `LFS_LDFLAGS` - Large file support linker flags. + +* `LFS_LIBS` - Large file support libraries. + +#### Other Tools #### + +* `RANLIB` - `ranlib` archive index tool. + +* `AR` - `ar` archiving tool. + +* `GETCONF` - `getconf` system configuration inspection tool. `getconf` is + currently used for finding out large file support flags to use, and + on Linux systems for finding out if we have an NPTL thread library or + not. + +### Cross System Root Locations ### + +* `erl_xcomp_sysroot` - The absolute path to the system root of the cross + compilation environment. Currently, the `crypto`, `odbc`, `ssh` and + `ssl` applications need the system root. These applications will be + skipped if the system root has not been set. The system root might be + needed for other things too. If this is the case and the system root + has not been set, `configure` will fail and request you to set it. + +* `erl_xcomp_isysroot` - The absolute path to the system root for includes + of the cross compilation environment. If not set, this value defaults + to `$erl_xcomp_sysroot`, i.e., only set this value if the include system + root path is not the same as the system root path. + +### Optional Feature, and Bug Tests ### + +These tests cannot (always) be done automatically when cross compiling. You +usually do not need to set these variables. Only set these if you really +know what you are doing. + +Note that some of these values will override results of tests performed +by `configure`, and some will not be used until `configure` is sure that +it cannot figure the result out. + +The `configure` script will issue a warning when a default value is used. +When a variable has been set, no warning will be issued. + +* `erl_xcomp_after_morecore_hook` - `yes|no`. Defaults to `no`. If `yes`, the + target system must have a working `__after_morecore_hook` that can be + used for tracking used `malloc()` implementations core memory usage. + This is currently only used by unsupported features. + +* `erl_xcomp_bigendian` - `yes|no`. No default. If `yes`, the target system + must be big endian. If `no`, little endian. This can often be + automatically detected, but not always. If not automatically detected, + `configure` will fail unless this variable is set. Since no default + value is used, `configure` will try to figure this out automatically. + +* `erl_xcomp_clock_gettime_cpu_time` - `yes|no`. Defaults to `no`. If `yes`, + the target system must have a working `clock_gettime()` implementation + that can be used for retrieving process CPU time. + +* `erl_xcomp_getaddrinfo` - `yes|no`. Defaults to `no`. If `yes`, the target + system must have a working `getaddrinfo()` implementation that can + handle both IPv4 and IPv6. + +* `erl_xcomp_gethrvtime_procfs_ioctl` - `yes|no`. Defaults to `no`. If `yes`, + the target system must have a working `gethrvtime()` implementation and + is used with procfs `ioctl()`. + +* `erl_xcomp_dlsym_brk_wrappers` - `yes|no`. Defaults to `no`. If `yes`, the + target system must have a working `dlsym(RTLD_NEXT, <S>)` implementation + that can be used on `brk` and `sbrk` symbols used by the `malloc()` + implementation in use, and by this track the `malloc()` implementations + core memory usage. This is currently only used by unsupported features. + +* `erl_xcomp_kqueue` - `yes|no`. Defaults to `no`. If `yes`, the target system + must have a working `kqueue()` implementation that returns a file + descriptor which can be used by `poll()` and/or `select()`. If `no` and + the target system has not got `epoll()` or `/dev/poll`, the kernel-poll + feature will be disabled. + +* `erl_xcomp_linux_clock_gettime_correction` - `yes|no`. Defaults to `yes` on + Linux; otherwise, `no`. If `yes`, `clock_gettime(CLOCK_MONOTONIC, _)` on + the target system must work. This variable is recommended to be set to + `no` on Linux systems with kernel versions less than 2.6. + +* `erl_xcomp_linux_nptl` - `yes|no`. Defaults to `yes` on Linux; otherwise, + `no`. If `yes`, the target system must have NPTL (Native POSIX Thread + Library). Older Linux systems have LinuxThreads instead of NPTL (Linux + kernel versions typically less than 2.6). + +* `erl_xcomp_linux_usable_sigaltstack` - `yes|no`. Defaults to `yes` on Linux; + otherwise, `no`. If `yes`, `sigaltstack()` must be usable on the target + system. `sigaltstack()` on Linux kernel versions less than 2.4 are + broken. + +* `erl_xcomp_linux_usable_sigusrx` - `yes|no`. Defaults to `yes`. If `yes`, + the `SIGUSR1` and `SIGUSR2` signals must be usable by the ERTS. Old + LinuxThreads thread libraries (Linux kernel versions typically less than + 2.2) used these signals and made them unusable by the ERTS. + +* `erl_xcomp_poll` - `yes|no`. Defaults to `no` on Darwin/MacOSX; otherwise, + `yes`. If `yes`, the target system must have a working `poll()` + implementation that also can handle devices. If `no`, `select()` will be + used instead of `poll()`. + +* `erl_xcomp_putenv_copy` - `yes|no`. Defaults to `no`. If `yes`, the target + system must have a `putenv()` implementation that stores a copy of the + key/value pair. + +* `erl_xcomp_reliable_fpe` - `yes|no`. Defaults to `no`. If `yes`, the target + system must have reliable floating point exceptions. + +Copyright and License +--------------------- + +> %CopyrightBegin% +> +> Copyright Ericsson AB 2009-2010. All Rights Reserved. +> +> The contents of this file are subject to the Erlang Public License, +> Version 1.1, (the "License"); you may not use this file except in +> compliance with the License. You should have received a copy of the +> Erlang Public License along with this software. If not, it can be +> retrieved online at http://www.erlang.org/. +> +> Software distributed under the License is distributed on an "AS IS" +> basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See +> the License for the specific language governing rights and limitations +> under the License. +> +> %CopyrightEnd% + + +<!-- + +Modifying This Document +----------------------- + +This document has been written using Markdown notation. This makes it possible +to easily generate a nice looking HTML version of this file. When modifying +this file, make sure that the modifications are made using valid Markdown +notation. 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