PERLSYNOLOGY(1)                  Perl Programmers Reference Guide                 PERLSYNOLOGY(1)



NAME
       perlsynology - Perl 5 on Synology DSM systems

DESCRIPTION
       Synology manufactures a vast number of Network Attached Storage (NAS) devices that are
       very popular in large organisations as well as small businesses and homes.

       The NAS systems are equipped with Synology Disk Storage Manager (DSM), which is a trimmed-
       down Linux system enhanced with several tools for managing the NAS. There are several
       flavours of hardware: Marvell Armada (ARMv5te, ARMv7l), Intel Atom (i686, x86_64),
       Freescale QorIQ (PPC), and more. For a full list see the Synology FAQ
       <http://forum.synology.com/wiki/index.php/What_kind_of_CPU_does_my_NAS_have>.

       Since it is based on Linux, the NAS can run many popular Linux software packages,
       including Perl. In fact, Synology provides a ready-to-install package for Perl, albeit
       version 5.8.6 which should be considered very old.

       There is an active user community that provides many software packages for the Synology
       DSM systems; at the time of writing this document they provide Perl version 5.8.8.

       This document describes various features of Synology DSM operating system that will affect
       how Perl 5 (hereafter just Perl) is configured, compiled and/or runs. It has been compiled
       and verified by Johan Vromans for the Synology DS413 (QorIQ), with feedback from H.Merijn
       Brand (DS213, ARMv5te).

   Setting up the build environment
       As DSM is a trimmed-down Linux system, it lacks many of the tools and libraries commonly
       found on Linux. The basic tools like sh, cp, rm, etc. are implemented using BusyBox
       <http://en.wikipedia.org/wiki/BusyBox>.

       ·   Using your favourite browser open the DSM management page and start the Package
           Center.

       ·   If you want to smoke test Perl, install "Perl".

       ·   In Settings, add the following Package Sources:

             http://www.cphub.net
             http://packages.quadrat4.de

       ·   Still in Settings, in Channel Update, select Beta Channel.

       ·   Press Refresh. In the left panel the item "Community" will appear.  Click it. Select
           "Bootstrap Installer Beta" and install it.

       ·   Likewise, install "iPKGui Beta".

           The application window should now show an icon for iPKGui.

       ·   Start iPKGui. Install the packages "make", "gcc" and "coreutils".

           If you want to smoke test Perl, install "patch".

       The next step is to add some symlinks to system libraries. For example, the development
       software expect a library "libm.so" that normally is a symlink to "libm.so.6". Synology
       only provides the latter and not the symlink.

       Here the actual architecture of the Synology system matters. You have to find out where
       the gcc libraries have been installed. Look in /opt for a directory similar to arm-none-
       linux-gnueab or powerpc-linux-gnuspe. In the instructions below I'll use powerpc-linux-
       gnuspe as an example.

       ·   On the DSM management page start the Control Panel.

       ·   Click Terminal, and enable SSH service.

       ·   Close Terminal and the Control Panel.

       ·   Open a shell on the Synology using ssh and become root.

       ·   Execute the following commands:

             cd /lib
             ln -s libm.so.6 libm.so
             ln -s libcrypt.so.1 libcrypt.so
             ln -s libdl.so.2 libdl.so
             cd /opt/powerpc-linux-gnuspe/lib
             ln -s /lib/libdl.so.2 libdl.so

       WARNING: When you perform a system software upgrade, these links will disappear and need
       to be re-established.

   Compiling Perl 5
       When the build environment has been set up, building and testing Perl is straightforward.
       The only thing you need to do is download the sources as usual, and add a file Policy.sh
       as follows:

         # Administrivia.
         perladmin="your.email AT goes.here"

         # Install Perl in a tree in /opt/perl instead of /opt/bin.
         prefix=/opt/perl

         # Select the compiler. Note that there is no 'cc' alias or link.
         cc=gcc

         # Build flags.
         ccflags="-DDEBUGGING"

         # Library and include paths.
         libpth="/lib"
         locincpth="/opt/include"
         loclibpth="/lib"

       You may want to create the destination directory and give it the right permissions before
       installing, thus eliminating the need to build Perl as a super user.

       In the directory where you unpacked the sources, issue the familiar commands:

         ./Configure -des
         make
         make test
         make install

   Known problems
       Configure

       No known problems yet

       Build

       Error message "No error definitions found".
           This error is generated when it is not possible to find the local definitions for
           error codes, due to the uncommon structure of the Synology file system.

           This error was fixed in the Perl development git for version 5.19, commit
           7a8f1212e5482613c8a5b0402528e3105b26ff24.

       Failing tests

       "ext/DynaLoader/t/DynaLoader.t"
           One subtest fails due to the uncommon structure of the Synology file system. The file
           "/lib/glibc.so" is missing.

           WARNING: Do not symlink "/lib/glibc.so.6" to "/lib/glibc.so" or some system components
           will start to fail.

   Smoke testing Perl 5
       If building completes successfully, you can set up smoke testing as described in the
       Test::Smoke documentation.

       For smoke testing you need a running Perl. You can either install the Synology supplied
       package for Perl 5.8.6, or build and install your own, much more recent version.

       Note that I could not run successful smokes when initiated by the Synology Task Scheduler.
       I resorted to initiating the smokes via a cron job run on another system, using ssh:

         ssh nas1 wrk/Test-Smoke/smoke/smokecurrent.sh

       Local patches

       When local patches are applied with smoke testing, the test driver will automatically
       request regeneration of certain tables after the patches are applied. The Synology
       supplied Perl 5.8.6 (at least on the DS413) is NOT capable of generating these tables. It
       will generate opcodes with bogus values, causing the build to fail.

       You can prevent regeneration by adding the setting

         'flags' => 0,

       to the smoke config, or by adding another patch that inserts

         exit 0 if $] == 5.008006;

       in the beginning of the "regen.pl" program.

   Adding libraries
       The above procedure describes a basic environment and hence results in a basic Perl. If
       you want to add additional libraries to Perl, you may need some extra settings.

       For example, the basic Perl does not have any of the DB libraries (db, dbm, ndbm, gdsm).
       You can add these using iPKGui, however, you need to set environment variable
       LD_LIBRARY_PATH to the appropriate value:

         LD_LIBRARY_PATH=/lib:/opt/lib
         export LD_LIBRARY_PATH

       This setting needs to be in effect while Perl is built, but also when the programs are
       run.

REVISION
       November 2013, for Synology DSM 4.3.3810.

AUTHOR
       Johan Vromans <jvromans AT squirrel.nl>

THANKS
       H. Merijn Brand <h.m.brand AT xs4all.nl>



perl v5.20.2                                2014-12-27                            PERLSYNOLOGY(1)