===========================================================================
                          OpenSource Erlang/OTP 
===========================================================================


Please read the whole file before attempting to build and install Erlang.
You can find more information about OpenSource Erlang at

  http://www.erlang.org/


%CopyrightBegin%

Copyright Ericsson AB 1998-2009. 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%


Portability
-----------

Erlang/OTP should be possible to build from source on any Unix
system, including Mac OS X.

Instructions for building from source on Windows are in the file README.win32.
Binary releases for Windows can be found at http://www.erlang.org/

At Ericsson we have a "Daily Build and Test" that runs on:
 
    Operating system        Versions
    -----------------------------------------------------------
    Solaris/Sparc32         8, 9, 10
    Solaris/Sparc64         10
    Solaris/x86             10
    Linux/Suse x86	    9.4, 10.1
    Linux/Suse x86_64	    10.0, 10.1, 11.0
    FreeBSD x86             7.1
    Mac OS X/Intel          10.4.11 (Tiger), 10.5.8 (Leopard)
    Windows		    XP SP3, 2003, Vista

We have also done some testing on Mac OS 10.6.0 (Snow Leopard).


Versions known *not* to work
-------------------------------------

Suse linux 9.1 is shipped with a patched GCC version 3.3.3, having the
rpm named gcc-3.3.3-41. That version has a serious optimization bug
that makes it unusable for building the Erlang emulator. Please
upgrade GCC to a newer version before building on Suse 9.1. Suse Linux
EnterpriSe edition 9 (SLES9) has gcc-3.3.3-43 and is not affected.

gcc-4.3.0 has a serious optimizer bug. It produces an Erlang emulator
that will crash immediately. The bug is supposed to be fixed in gcc-4.3.1.

FreeBSD had a bug which caused kqueue/poll/select to fail to detect
that a writev() on a pipe has been made. This bug should have been fixed
in FreeBSD 6.3 and FreeBSD 7.0. More information can be found at:
* http://www.freebsd.org/cgi/cvsweb.cgi/src/sys/kern/sys_pipe.c
* http://lists.freebsd.org/pipermail/freebsd-arch/2007-September/006790.html
NetBSD and DragonFlyBSD probably have or have had the same bug.

getcwd() on Solaris 9 can cause an emulator crash. If you have async-threads
enabled you can increase the stack size of the async-threads as a temporary
workaround. See the +a command-line argument in the documentation of erl(1).
Without async-threads the emulator isn't as vulnerable to this bug, but if
you hit it without async-threads the only workaround available is to enable
async-threads and increase the stack size of the async-threads.
Sun has however released patches that fixes the issue:
Problem Description: 6448300 large mnttab can cause stack overrun during
                     Solaris 9 getcwd
* http://sunsolve.sun.com/search/document.do?assetkey=1-21-112874-40-1&searchclause=6448300
* http://sunsolve.sun.com/search/document.do?assetkey=1-21-114432-29-1&searchclause=6448300

Required utilities
------------------

These are the tools you will need in order to unpack and build Erlang/OTP.

  Unpacking
  ---------

  GNU unzip, or a modern uncompress.

  A TAR program that understands the GNU TAR format for long
  filenames (such as GNU TAR).
  

  Compiling
  ---------

  GNU make

  GNU C compiler

  Perl 5

  GNU m4		If hipe (native code) support is enabled.

  ncurses		(Or termcap or termlib.) The development headers and
                        libraries are needed, often known as ncurses-devel.
			(Use --without-termcap to build without any of these
			libraries. Only the old shell (without any line
			editing) can be used.)

  OpenSSL	        Optional, but needed for building the Erlang/OTP
                        applications 'ssl' and 'crypto'. You need the
                        "development package" of OpenSSL, i.e. including
                        the header files. For building the application 'ssl'
			the OpenSSL binary command program 'openssl' is also
			needed. 

			At least version 0.9.7 of OpenSSL is required.

  Sun Java jdk-1.5.0    Or higher. Optional but needed for building
			the Erlang/OTP application 'jinterface' and parts
			of 'ic' and 'orber'. We have also tested
			IBM's JDK 1.5.0.

  X Windows             Optional, but development headers and libraries
                        are needed to build the Erlang/OTP application 'gs'
			on Unix/Linux.

  sed			There seem to be some problems with some of the
			'sed' version on Solaris. Make sure "/bin/sed"
			or "/usr/bin/sed" is used on the Solaris platform.

  Flex                  Optional, headers and libraries are needed to 
                        build the flex scanner for the megaco application
                        on Unix/Linux.


  Installing
  ----------

  An 'install' program that can take multiple file names.


How to build and install Erlang/OTP
-----------------------------------

Start by unpacking the Erlang/OTP distribution file with your
GNU compatible TAR

  1)    gunzip -c otp_src_R13B02.tar.gz | tar xf -
  1)    zcat otp_src_R13B02.tar.gz | tar xf -

Now cd into the base directory

  2)    cd otp_src_R13B02

On some platforms Perl may behave strangely if certain locales are set,
so optionally you may need to set the LANG variable:

  3a) LANG=C; export LANG #Bourne shell
or
  3b) setenv LANG C #C-shell

Run the following commands

  4a)    ./configure  [ options ]
or
  4b)    ./configure --prefix=<BaseDir> [ other options ]

By default, Erlang/OTP will be installed in /usr/local/{bin,lib/erlang,man/man1}.
To instead install in <BaseDir>/{bin,lib/erlang,man/man1}, use the --prefix=<BaseDir>
option.

If you upgraded the source with some patch you may need to clean up
from previous builds before the new build. Do a "make clean"; see
"Caveats" below.

  5)    make
  6)    make install

Let's go through them in some detail:

Step 4 runs a configuration script created by the GNU autoconf
utility, which checks for system specific features and then creates a
number of makefiles.

The configure script allows you to customize a number of parameters;
type "./configure --help" for details.

One of the things you can specify is where Erlang/OTP should be installed: by
default Erlang/OTP will be installed in /usr/local/{bin,lib/erlang,man/man1};
to keep the same structure but install in a different place, <Dir> say,
use the --prefix argument like this:
"./configure --prefix=<Dir>".

This step will also configure any additional libraries unpacked in step 3
(if you didn't add any of the extra libraries configure will issue a warning
saying that there is no configuration information in lib; this warning can
safely be ignored).

You can also specify where the OpenSSL include and library files are
located, or alternatively disable the use of SSL and Crypto.
(The details can be found by typing './configure --help'.)

Other options are:

	--enable-smp-support	See the next section.

	--disable-smp-support	See the next section.

	--disable-threads	Disable support for threaded I/O;
				this option also disables building
				of the SMP emulator. (See the next section.)

	--enable-threads	Enable support for threaded I/O.
				(This is the default if SMP support is enabled.
				See the next section.)
				
	--disable-hipe   	Disable HiPE (High-Performance Erlang).
				HiPE will automatically be enabled on
				supported platforms.
	

    Step 5 builds the Erlang/OTP system. On a fast computer,
this will take about 5 minutes. After completion of this step,
you should have a working Erlang/OTP system which you can
try by typing "bin/erl". This should start up Erlang/OTP and give you
a prompt.

    Step 6 is optional. It installs Erlang/OTP (if you change your
mind about where you wish to install you can rerun step 4, without
having to do step 5 again).

The source tree is delivered with a lot of platform independent
build results already pre-built. If you want to remove these pre-built
files, invoke './otp_build remove_prebuilt_files' from the $ERL_TOP
directory. After you have done this, you can build exactly the same way
as before, but the build process will take a much longer time.

NOTE: Doing 'make clean' in an arbitrary directory of the source tree,
may remove files needed for bootstrapping the build. Doing
'./otp_build save_bootstrap' from the $ERL_TOP directory before
doing 'make clean' will ensure that it will be possible to build after
doing 'make clean'. './otp_build save_bootstrap' will be invoked
automatically when 'make' is invoked from ERL_TOP with either the
clean target, or the default target. It is also automatically invoked
if './otp_build remove_prebuilt_files' is invoked.

If you or your system has special requirements please read the
Makefile for additional configuration information.

Support for SMP (Symmetric Multi Processing)
--------------------------------------------

An emulator with SMP support will be built by default on most platforms
if a usable POSIX thread library or native Windows threads is found.

You can force building of an SMP emulator, by using
"./configure --enable-smp-support". However, if configure doesn't
automatically enable SMP support, the build is very likely to fail.

Use "./configure --disable-smp-support" if you for some reason don't
want to have the emulator with SMP support built.

If SMP support is enabled, support for threaded I/O will also be turned on
(also in the emulator without SMP support).

The 'erl' command will automatically start the SMP emulator if the
computer has more than one logical processor. You can force a start
of the emulator with SMP support by passing '-smp enable' as
command line arguments to erl, and you can force a start of the
emulator without SMP support by passing '-smp disable'.

How to install the Erlang/OTP documentation
-------------------------------------------

For some graphical tools to find the on-line help you have to install
the HTML documentation on top of the installed OTP applications, i.e.

        cd <PrefixDir>/lib/erlang
        gunzip -c otp_html_R<XY>B-<Z>.tar.gz | tar xf -

For "erl -man <page>" to work the Unix manual pages have to be
installed in the same way, i.e.

        cd <PrefixDir>/lib/erlang
        gunzip -c otp_man_R<XY>B-<Z>.tar.gz | tar xf -


GS (Graphic System)
-------------------

GS now Tcl/Tk 8.4. It will be searched for when starting GS.


Using HiPE
----------

HiPE supports the following system configurations:

x86:
	All 32-bit and 64-bit mode processors should work.

	The following systems are supported:

	Linux:
		Fedora Core is supported.
		Both 32-bit and 64-bit modes are supported.

		NPTL glibc is strongly preferred, or a LinuxThreads
		glibc configured for "floating stacks". Old non-floating
		stacks glibcs have a fundamental problem that makes HiPE
		support	and threads support mutually exclusive.
	Solaris:
		Solaris 10 (32-bit and 64-bit) and 9 (32-bit) are
		supported.

		The build requires a version of the GNU C compiler (gcc)
		that has been configured to use the GNU assembler (gas).
		Sun's x86 assembler is emphatically /not/ supported.
	FreeBSD:
		FreeBSD 6.1 and 6.2 in 32-bit and 64-bit modes should work.

PowerPC:
	All 32-bit 6xx/7xx(G3)/74xx(G4) processors should work.
	32-bit mode on 970 (G5) and POWER5 is untested and may need
	compiler changes (to avoid using the "mcrxr" instruction).

	Linux (Yellow Dog) and Mac OSX 10.3.9 are supported.

SPARC:
	All UltraSPARC processors running 32-bit user code should work.

	Solaris 9 and Linux (Aurora) are supported.

	On Solaris the build requires a gcc that has been configured
	to use Sun's assembler and linker. Using the GNU assembler but
	Sun's linker has been known to cause problems.
ARM:
	ARMv5TE (i.e. XScale) processors should work.
	Both big-endian and little-endian modes are supported.

	Linux is supported.

HiPE is automatically enabled on the following systems:
	x86 in 32-bit mode: Linux, Solaris, FreeBSD
	x86 in 64-bit mode: Linux, Solaris, FreeBSD
	PowerPC: Linux, MacOSX
	SPARC: Linux
	ARM: Linux
On other supported systems you need to "./configure --enable-hipe".


If you are running on a platform supporting HiPE and if
you have not disabled HiPE, you can compile a module into
native code like this from the Erlang shell:

	c(Module, native).

or

	c(Module, [native|OtherOptions]).

Using the erlc program, write like this:

	erlc +native Module.erl

The native code will be placed into the beam file and automatically
loaded when the beam file is loaded.

To add hipe options, write like this from the Erlang shell:

	c(Module, [native,{hipe,HipeOptions}|MoreOptions]).

Use

	hipe:help_options().

to print out the available options.


Mac OS X (Darwin)
-----------------

We test Mac OS X 10.4.11 (Tiger) and Mac OS X 10.5.x (Leopard)
in our daily builds (but only on Intel processors).

Make sure that the command "hostname" returns a valid fully qualified
host name (this is configured in "/etc/hostconfig").

If you develop linked-in drivers (shared library) you need to link
using "gcc" and the flags "-bundle -flat_namespace -undefined
suppress". You also include "-fno-common" in CFLAGS when
compiling. Use ".so" as the library suffix.

Universal 32bit binaries can be built on an Intel Mac using the
--enable-darwin-universal configure option. There still may occur
problems with certain applications using this option, but the base
system should run smoothly.

When building universal binaries on a PowerPC Mac (at least on Tiger),
you must point out a suitable SDK that contains universal binaries.
For instance, to build universal binaries for Tiger (10.4):

CFLAGS="-isysroot /Developer/SDKs/MacOSX10.4u.sdk" LDFLAGS="-isysroot /Developer/SDKs/MacOSX10.4u.sdk" 	./configure --enable-darwin-universal

Also, if you run Leopard, but want to build for Tiger, you must do

export MACOSX_DEPLOYMENT_TARGET=10.4

before running the above configure command.

Experimental support for 64bit x86 darwin binaries can be enabled
using the --enable-darwin-64bit configure flag. The 64bit binaries are
best built and run on Leopard, but most of the system also works on
Tiger (Tiger's 64bit libraries are, however, limited; therefore e.g. odbc,
crypto, ssl etc. are not supported in Tiger). 64bit PPC binaries are not
supported and we have no plans to add such support (no machines to
test on).

Universal binaries and 64bit binaries are mutually exclusive options.


Make and the variable "ERL_TOP"
-------------------------------

All the makefiles in the entire directory tree use the environment
variable ERL_TOP to find the absolute path of the installation. The
configure script will figure this out and set it in the top level
Makefile (which, when building, it will pass on). However, when
developing it is sometimes convenient to be able to run make in a
subdirectory. To do this you must set the ERL_TOP variable
before you run make.

For example, assume your GNU make program is called "make" and you
want to rebuild the application STDLIB, then you could do:

  cd lib/stdlib; env ERL_TOP=<Dir> make

where <Dir> would be what you find ERL_TOP is set to in the top level
Makefile.


Authors
-------
Authors are mostly listed in the application's AUTHORS files,
that is $ERL_TOP/lib/*/AUTHORS and $ERL_TOP/erts/AUTHORS,
not in the individual source files.


More Information
----------------

More information can be found at http://www.erlang.org.