3 If you read this file _as_is_, just ignore the funny characters you
4 see. It is written in the POD format (see pod/perlpod.pod) which is
5 specially designed to be readable as is.
9 perlandroid - Perl under Android
13 The first portions of this document contains instructions
14 to cross-compile Perl for Android 2.0 and later, using the
15 binaries provided by Google. The latter portions describe how to build
16 perl native using one of the toolchains available on the Play Store.
20 This document describes how to set up your host environment when
21 attempting to build Perl for Android.
23 =head1 Cross-compilation
25 These instructions assume an Unixish build environment on your host system;
26 they've been tested on Linux and OS X, and may work on Cygwin and MSYS.
27 While Google also provides an NDK for Windows, these steps won't work
28 native there, although it may be possible to cross-compile through different
31 If your host system's architecture is 32 bits, remember to change the
32 C<x86_64>'s below to C<x86>'s. On a similar vein, the examples below
33 use the 4.8 toolchain; if you want to use something older or newer (for
34 example, the 4.4.3 toolchain included in the 8th revision of the NDK), just
35 change those to the relevant version.
37 =head2 Get the Android Native Development Kit (NDK)
39 You can download the NDK from L<https://developer.android.com/tools/sdk/ndk/index.html>.
40 You'll want the normal, non-legacy version.
42 =head2 Determine the architecture you'll be cross-compiling for
44 There's three possible options: arm-linux-androideabi for ARM,
45 mipsel-linux-android for MIPS, and simply x86 for x86.
46 As of 2014, most Android devices run on ARM, so that is generally a safe bet.
48 With those two in hand, you should add
50 $ANDROID_NDK/toolchains/$TARGETARCH-4.8/prebuilt/`uname | tr '[A-Z]' '[a-z]'`-x86_64/bin
52 to your C<PATH>, where C<$ANDROID_NDK> is the location where you unpacked the
53 NDK, and C<$TARGETARCH> is your target's architecture.
55 =head2 Set up a standalone toolchain
57 This creates a working sysroot that we can feed to Configure later.
59 $ export ANDROID_TOOLCHAIN=/tmp/my-toolchain-$TARGETARCH
60 $ export SYSROOT=$ANDROID_TOOLCHAIN/sysroot
61 $ $ANDROID_NDK/build/tools/make-standalone-toolchain.sh \
62 --platform=android-9 \
63 --install-dir=$ANDROID_TOOLCHAIN \
64 --system=`uname | tr '[A-Z]' '[a-z]'`-x86_64 \
65 --toolchain=$TARGETARCH-4.8
69 adb is the Android Debug Bridge. For our purposes, it's basically a way
70 of establishing an ssh connection to an Android device without having to
71 install anything on the device itself, as long as the device is either on
72 the same local network as the host, or it is connected to the host through
75 Perl can be cross-compiled using either adb or a normal ssh connection;
76 in general, if you can connect your device to the host using a USB port,
77 or if you don't feel like installing an sshd app on your device,
78 you may want to use adb, although you may be forced to switch to ssh if
79 your device is not rooted and you're unlucky -- more on that later.
80 Alternatively, if you're cross-compiling to an emulator, you'll have to
85 To use adb, download the Android SDK from L<https://developer.android.com/sdk/index.html>.
86 The "SDK Tools Only" version should suffice -- if you downloaded the ADT
87 Bundle, you can find the sdk under F<$ADT_BUNDLE/sdk/>.
89 Add F<$ANDROID_SDK/platform-tools> to your C<PATH>, which should give you access
90 to adb. You'll now have to find your device's name using C<adb devices>,
91 and later pass that to Configure through C<-Dtargethost=$DEVICE>.
93 However, before calling Configure, you need to check if using adb is a
94 viable choice in the first place. Because Android doesn't have a F</tmp>,
95 nor does it allow executables in the sdcard, we need to find somewhere in
96 the device for Configure to put some files in, as well as for the tests
97 to run in. If your device is rooted, then you're good. Try running these:
99 $ export TARGETDIR=/mnt/asec/perl
100 $ adb -s $DEVICE shell "echo sh -c '\"mkdir $TARGETDIR\"' | su --"
102 Which will create the directory we need, and you can move on to the next
103 step. F</mnt/asec> is mounted as a tmpfs in Android, but it's only
106 If your device is not rooted, you may still be in luck. Try running this:
108 $ export TARGETDIR=/data/local/tmp/perl
109 $ adb -s $DEVICE shell "mkdir $TARGETDIR"
111 If the command works, you can move to the next step, but beware:
112 B<You'll have to remove the directory from the device once you are done!
113 Unlike F</mnt/asec>, F</data/local/tmp> may not get automatically garbage
114 collected once you shut off the phone>.
116 If neither of those work, then you can't use adb to cross-compile to your
117 device. Either try rooting it, or go for the ssh route.
121 To use ssh, you'll need to install and run a sshd app and set it up
122 properly. There are several paid and free apps that do this rather
123 easily, so you should be able to spot one on the store.
124 Remember that Perl requires a passwordless connection, so set up a
127 Note that several apps spew crap to stderr every time you
128 connect, which can throw off Configure. You may need to monkeypatch
129 the part of Configure that creates C<run-ssh> to have it discard stderr.
131 Since you're using ssh, you'll have to pass some extra arguments to
134 -Dtargetrun=ssh -Dtargethost=$TARGETHOST -Dtargetuser=$TARGETUSER -Dtargetport=$TARGETPORT
136 =head2 Configure and beyond
138 With all of the previous done, you're now ready to call Configure.
140 If using adb, a "basic" Configure line will look like this:
142 $ ./Configure -des -Dusedevel -Dusecrosscompile -Dtargetrun=adb \
143 -Dcc=$TARGETARCH-gcc \
145 -Dtargetdir=$TARGETDIR \
148 If using ssh, it's not too different -- we just change targetrun to ssh,
149 and pass in targetuser and targetport. It ends up looking like this:
151 $ ./Configure -des -Dusedevel -Dusecrosscompile -Dtargetrun=ssh \
152 -Dcc=$TARGETARCH-gcc \
154 -Dtargetdir=$TARGETDIR \
155 -Dtargethost="$TARGETHOST" \
156 -Dtargetuser=$TARGETUSER \
157 -Dtargetport=$TARGETPORT
159 Now you're ready to run C<make> and C<make test>!
161 As a final word of warning, if you're using adb, C<make test> may appear to
162 hang; this is because it doesn't output anything until it finishes
163 running all tests. You can check its progress by logging into the
164 device, moving to F<$TARGETDIR>, and looking at the file F<output.stdout>.
172 If you are targetting x86 Android, you will have to change C<$TARGETARCH-gcc>
173 to C<i686-linux-android-gcc>.
177 On some older low-end devices -- think early 2.2 era -- some tests,
178 particularly F<t/re/uniprops.t>, may crash the phone, causing it to turn
179 itself off once, and then back on again.
185 While Google doesn't provide a native toolchain for Android,
186 you can still get one from the Play Store.
190 You may be able to get the CCTools app, which is free.
191 Keep in mind that you want a full toolchain;
192 some apps tend to default to installing only a barebones
193 version without some important utilities, like ar or nm.
195 Once you have the toolchain set up properly, the only
196 remaining hurdle is actually locating where in the device it was installed
197 in. For example, CCTools installs its toolchain in
198 F</data/data/com.pdaxrom.cctools/root/cctools>. With the path in hand,
199 compiling perl is little more than:
201 export SYSROOT=<location of the native toolchain>
202 export LD_LIBRARY_PATH="$SYSROOT/lib:`pwd`:`pwd`/lib:`pwd`/lib/auto:$LD_LIBRARY_PATH"
203 sh Configure -des -Dsysroot=$SYSROOT -Alibpth="/system/lib /vendor/lib"
207 L<Termux|https://termux.com/> provides an Android terminal emulator and Linux environment.
208 It comes with a cross-compiled perl already installed.
210 Natively compiling perl 5.30 or later should be as straightforward as:
212 sh Configure -des -Alibpth="/system/lib /vendor/lib"
214 This certainly works on Android 8.1 (Oreo) at least...
218 Brian Fraser <fraserbn@gmail.com>