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 (ARMv5tel, 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, depending on the version of DSM the installed perl
ranges from 5.8.6 on DSM-4.3 to 5.18.4 on DSM-5.1.
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 5.18.4.
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, ARMv5tel).
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 (or
/opt/arm-none-linux-gnueabi/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@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
March 2015, for Synology DSM 5.1.5022.
AUTHOR
Johan Vromans <jvromans@squirrel.nl> H. Merijn Brand <h.m.brand@xs4all.nl>
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