Split out license section from README into LICENSE
[termux-packages] / README.md
1 Termux packages
2 ===============
3 [![Join the chat at https://gitter.im/termux/termux](https://badges.gitter.im/termux/termux.svg)](https://gitter.im/termux/termux)
4
5 This project contains scripts and patches to build packages for the
6 [Termux](https://termux.com/) Android application.
7
8 Build environment on Ubuntu 16.10
9 =================================
10 Packages are built using Ubuntu 16.10. Perform the following steps to configure a Ubuntu 16.10 installation:
11
12 - Run `scripts/setup-ubuntu.sh` to install required packages and setup the `/data/` folder.
13
14 - Run `scripts/setup-android-sdk.sh` to install the Android SDK and NDK at `$HOME/lib/android-{sdk,ndk}`.
15
16 There is also a [Vagrantfile](scripts/Vagrantfile) available for setting up an Ubuntu environment using a virtual machine on other operating systems.
17
18 Build environment using Docker
19 ==============================
20 On other Linux distributions than Ubuntu 16.10 (or on other platforms than Linux) the best course
21 of action is to setup a Docker container for building packages by executing:
22
23 ./scripts/run-docker.sh # On Linux and macOS.
24 .\scripts\run-docker.ps1 # On Windows.
25
26 This will setup a container (from an image created by [scripts/Dockerfile](scripts/Dockerfile))
27 suitable for building packages.
28
29 This source folder is mounted as the /root/termux-packages data volume, so changes are kept
30 in sync between the host and the container when trying things out before committing, and built
31 deb files will be available on the host in the `debs/` directory just as when building on the host.
32
33 Build commands can be given to be executed in the docker container directly:
34
35 ./scripts/run-docker.sh ./build-package.sh libandroid-support
36
37 will launch the docker container, execute the `./build-package.sh libandroid-support`
38 command inside it and afterwards return you to the host prompt, with the newly built
39 deb in `debs/` to try out.
40
41 Building a package
42 ==================
43 The basic build operation is to run `./build-package.sh $PKG`, which:
44
45 1. Sets up a patched stand-alone Android NDK toolchain if necessary.
46
47 2. Reads `packages/$PKG/build.sh` to find out where to find the source code of the package and how to build it.
48
49 3. Extracts the source in `$HOME/.termux-build/$PKG/src`.
50
51 4. Applies all patches in packages/$PKG/\*.patch.
52
53 5. Builds the package under `$HOME/.termux-build/$PKG/` (either in the build/ directory there or in the
54 src/ directory if the package is specified to build in the src dir) and installs it to `$PREFIX`.
55
56 6. Extracts modified files in `$PREFIX` into `$HOME/.termux-build/$PKG/massage` and massages the
57 files there for distribution (removes some files, splits it up in sub-packages, modifies elf files).
58
59 7. Creates a deb package file for distribution in `debs/`.
60
61 Reading [build-package.sh](build-package.sh) is the best way to understand what is going on.
62
63 Additional utilities
64 ====================
65 * build-all.sh: used for building all packages in the correct order (using buildorder.py).
66
67 * clean.sh: used for doing a clean rebuild of all packages.
68
69 * scripts/check-pie.sh: Used for verifying that all binaries are using PIE, which is required for Android 5+.
70
71 * scripts/check-versions.sh: used for checking for package updates.
72
73 * scripts/list-packages.sh: used for listing all packages with a one-line summary.
74
75
76 Resources
77 =========
78 * [Android changes for NDK developers](https://android.googlesource.com/platform/bionic/+/master/android-changes-for-ndk-developers.md)
79
80 * [Linux From Scratch](http://www.linuxfromscratch.org/lfs/view/stable/)
81
82 * [Beyond Linux From Scratch](http://www.linuxfromscratch.org/blfs/view/stable/)
83
84 * [Cross-Compiled Linux From Scratch](http://www.clfs.org/view/CLFS-3.0.0-SYSVINIT/mips64-64/)
85
86 * [OpenWrt](https://openwrt.org/) as an embedded Linx distribution contains [patches and build scripts](https://dev.openwrt.org/browser/packages)
87
88 * http://dan.drown.org/android contains [patches for cross-compiling to Android](http://dan.drown.org/android/src/) as well as [work notes](http://dan.drown.org/android/worknotes.html), including a modified dynamic linker to avoid messing with `LD_LIBRARY_PATH`.
89
90 * [Kivy recipes](https://github.com/kivy/python-for-android/tree/master/pythonforandroid/recipes) contains recipes for building packages for Android.
91
92
93 Common porting problems
94 =======================
95 * The Android bionic libc does not have iconv and gettext/libintl functionality built in. A `libandroid-support` package contains these and may be used by all packages.
96
97 * "error: z: no archive symbol table (run ranlib)" usually means that the build machines libz is used instead of the one for cross compilation, due to the builder library -L path being setup incorrectly
98
99 * rindex(3) does not exist, but strrchr(3) is preferred anyway.
100
101 * <sys/termios.h> does not exist, but <termios.h> is the standard location.
102
103 * <sys/fcntl.h> does not exist, but <fcntl.h> is the standard location.
104
105 * <sys/timeb.h> does not exist (removed in POSIX 2008), but ftime(3) can be replaced with gettimeofday(2).
106
107 * <glob.h> does not exist, but is available through the `libandroid-glob` package.
108
109 * SYSV shared memory is not supported by the kernel. A `libandroid-shmem` package, which emulates SYSV shared memory on top of the [ashmem](http://elinux.org/Android_Kernel_Features#ashmem) shared memory system, is available. Use it with `LDFLAGS+=" -landroid-shmem`.
110
111 * SYSV semaphores is not supported by the kernel. Use unnamed POSIX semaphores instead (named semaphores are unimplemented).
112
113 dlopen() and RTLD_* flags
114 =================================
115 <dlfcn.h> originally declares
116
117 enum { RTLD_NOW=0, RTLD_LAZY=1, RTLD_LOCAL=0, RTLD_GLOBAL=2, RTLD_NOLOAD=4}; // 32-bit
118 enum { RTLD_NOW=2, RTLD_LAZY=1, RTLD_LOCAL=0, RTLD_GLOBAL=0x00100, RTLD_NOLOAD=4}; // 64-bit
119
120 These differs from glibc ones in that
121
122 1. They are not preprocessor #define:s so cannot be checked for with `#ifdef RTLD_GLOBAL`. Termux patches this to #define values for compatibility with several packages.
123 2. They differ in value from glibc ones, so cannot be hardcoded in files (DLFCN.py in python does this)
124 3. They are missing some values (`RTLD_BINDING_MASK`, `RTLD_NOLOAD`, ...)
125
126 RPATH, RUNPATH AND LD\_LIBRARY\_PATH
127 ====================================
128 On desktop linux the linker searches for shared libraries in:
129
130 1. `RPATH` - a list of directories which is linked into the executable, supported on most UNIX systems. It is ignored if `RUNPATH` is present.
131 2. `LD_LIBRARY_PATH` - an environment variable which holds a list of directories
132 3. `RUNPATH` - same as `RPATH`, but searched after `LD_LIBRARY_PATH`, supported only on most recent UNIX systems
133
134 The Android linker, /system/bin/linker, does not support RPATH or RUNPATH, so we set `LD_LIBRARY_PATH=$PREFIX/lib` and try to avoid building useless rpath entries (which the linker warns about) with --disable-rpath configure flags. NOTE: Starting from Android 7.0 RUNPATH (but not RPATH) is supported.
135
136 Warnings about unused DT entries
137 ================================
138 Starting from 5.1 the Android linker warns about VERNEED (0x6FFFFFFE) and VERNEEDNUM (0x6FFFFFFF) ELF dynamic sections (WARNING: linker: $BINARY: unused DT entry: type 0x6ffffffe/0x6fffffff). These may come from version scripts (`-Wl,--version-script=`). The termux-elf-cleaner utilty is run from build-package.sh and should normally take care of that problem. NOTE: Starting from Android 6.0 symbol versioning is supported.