| 1 | termux-packages |
| 2 | =============== |
| 3 | This project contains scripts and patches to cross compile and package packages for |
| 4 | the [Termux](http://termux.com/) Android application. |
| 5 | |
| 6 | |
| 7 | Overview |
| 8 | ======== |
| 9 | In a non-rooted Android device an app such as Termux may not write to system locations, |
| 10 | which is why every package is installed inside the private file area of the Termux app: |
| 11 | PREFIX=/data/data/com.termux/files/usr |
| 12 | |
| 13 | For simplicity while developing and building, the build scripts here assume that a /data |
| 14 | folder is reserved for use on the host builder, which requires setup: |
| 15 | sudo mkdir /data |
| 16 | sudo chown $USER /data |
| 17 | |
| 18 | The basic flow is then to run "./build-package.sh $PKG", which |
| 19 | - Sets up a patched stand-alone Android NDK toolchain |
| 20 | - Reads packages/$PKG/build.sh to find out where to find the source code of the |
| 21 | package and how to build it. |
| 22 | - Applies all patches in packages/$PKG/\*.patch |
| 23 | - Builds the package and installs it to $PREFIX |
| 24 | - Packages the package in one or more .dpkg files for distribution |
| 25 | Reading and following build-package.sh is the best way to understand what's going on here. |
| 26 | |
| 27 | Additional utilities are contained here: |
| 28 | - build-all.sh, used for building all packages in the correct order (using buildorder.py) |
| 29 | - check-pie.sh, used for verifying that all binaries are using PIE, which is required for Android 5+ |
| 30 | - check-versions.sh, used for checking for package updates |
| 31 | - clean-rebuild-all.sh, used for doing a clean rebuild of all packages (takes a couple of hours) |
| 32 | - list-packages.sh, used for listing all packages with a one-line summary |
| 33 | |
| 34 | |
| 35 | Resources about cross-compiling packages |
| 36 | ======================================== |
| 37 | * [Linux From Scratch](http://www.linuxfromscratch.org/blfs/view/svn/index.html) |
| 38 | |
| 39 | * [Beyond Linux From Scratch](http://www.linuxfromscratch.org/blfs/view/svn/) |
| 40 | |
| 41 | * [Cross-Compiled Linux From Scratch](http://cross-lfs.org/view/svn/x86_64-64/) |
| 42 | |
| 43 | * [OpenWrt](https://openwrt.org/), an embedded Linx distribution, contains [patches and build scripts](https://dev.openwrt.org/browser/packages) |
| 44 | |
| 45 | * 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. |
| 46 | |
| 47 | * [CCTools](http://cctools.info/index.php?title=Main_Page) is an Android native IDE containing [patches for several programs](https://code.google.com/p/cctools/source/browse/#svn%2Ftrunk%2Fcctools-repo%2Fpatches) and [a bug tracker](https://code.google.com/p/cctools/issues/list). |
| 48 | |
| 49 | * [BotBrew](http://botbrew.com/) was a package manager for rooted devices with [sources on github](https://github.com/jyio/botbrew). Based on opkg and was transitioning to apt. |
| 50 | |
| 51 | * [Kivy recipes](https://github.com/kivy/python-for-android/tree/master/recipes) contains recipes for building packages for Android. |
| 52 | |
| 53 | |
| 54 | Common porting problems |
| 55 | ======================= |
| 56 | * The Android bionic libc does not have iconv and gettext/libintl functionality built in. A package from the NDK, libandroid-support, |
| 57 | contains these and may be used by all packages. |
| 58 | |
| 59 | * "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 |
| 60 | |
| 61 | * rindex(3) is defined in <strings.h> but does not exist in NDK, but strrchr(3) from <string.h> is preferred anyway |
| 62 | |
| 63 | * <sys/termios.h> does not exist, but <termios.h> is the standard location. |
| 64 | |
| 65 | * <sys/fcntl.h> does not exist, but <fcntl.h> is the standard location. |
| 66 | |
| 67 | * glob(3) system function (glob.h) - not in bionic, but use the libglob package |
| 68 | |
| 69 | * undefined reference to 'rpl_malloc' and/or 'rpl_realloc': These functions are added by some autoconf setups |
| 70 | when it fails to detect 0-safe malloc and realloc during cross-compilating. Avoided by defining |
| 71 | "ac_cv_func_malloc_0_nonnull=yes ac_cv_func_realloc_0_nonnull=yes". |
| 72 | See http://wiki.buici.com/xwiki/bin/view/Programing+C+and+C%2B%2B/Autoconf+and+RPL_MALLOC |
| 73 | |
| 74 | * cmake and cross compiling: http://www.cmake.org/Wiki/CMake_Cross_Compiling |
| 75 | CMAKE_FIND_ROOT_PATH=$TERMUX_PREFIX to search there. |
| 76 | CMAKE_FIND_ROOT_PATH_MODE_LIBRARY=ONLY and |
| 77 | CMAKE_FIND_ROOT_PATH_MODE_INCLUDE=ONLY |
| 78 | for only searching there and don't fall back to build machines |
| 79 | |
| 80 | * Android is removing sys/timeb.h because it was removed in POSIX 2008, but ftime(3) can be replaced with gettimeofday(2) |
| 81 | |
| 82 | * mempcpy(3) is a GNU extension. We have added it to <string.h> provided TERMUX_EXPOSE_MEMPCPY is defined, |
| 83 | so use something like CFLAGS+=" -DTERMUX_EXPOSE_MEMPCPY=1" for packages expecting that function to exist. |
| 84 | |
| 85 | |
| 86 | dlopen() and RTLD_* flags |
| 87 | ================================= |
| 88 | <dlfn.h> declares |
| 89 | |
| 90 | > enum { RTLD_NOW = 2, RTLD_LAZY = 1, RTLD_LOCAL = 0, RTLD_GLOBAL = 0x00100, RTLD_NOLOAD = 4}; // 64 bit |
| 91 | > enum { RTLD_NOW = 0, RTLD_LAZY = 1, RTLD_LOCAL = 0, RTLD_GLOBAL = 2, RTLD_NOLOAD = 4}; // 32 bit |
| 92 | |
| 93 | These differs from glibc ones in that |
| 94 | |
| 95 | 1. They are not preprocessor #define:s so cannot be checked for with #ifdef RTLD_GLOBAL (dln.c in ruby does this) |
| 96 | 2. They differ in value from glibc ones, so cannot be hardcoded in files (DLFCN.py in python does this) |
| 97 | 3. They are missing some values (RTLD_BINDING_MASK, RTLD_NOLOAD, ...) |
| 98 | |
| 99 | |
| 100 | RPATH, LD_LIBRARY_PATH AND RUNPATH |
| 101 | ================================== |
| 102 | On desktop linux the linker searches for shared libraries in: |
| 103 | 1. RPATH - a list of directories which is linked into the executable, supported on most UNIX systems. It is ignored if RUNPATH is present. |
| 104 | 2. LD_LIBRARY_PATH - an environment variable which holds a list of directories |
| 105 | 3. RUNPATH - same as RPATH, but searched after LD_LIBRARY_PATH, supported only on most recent UNIX systems, e.g. on most current Linux systems |
| 106 | The Android linker (/system/bin/linker) does not support RPATH or RUNPATH, so we set LD_LIBRARY_PATH=$USR/lib and try to avoid building |
| 107 | useless rpath entries with --disable-rpath configure flags. |
| 108 | Another option to avoid depending on LD_LIBRARY_PATH would be supplying a custom linker - this is not done due to the overhead of maintaining a custom linker. |
| 109 | |
| 110 | |
| 111 | Warnings about unused DT entries |
| 112 | ================================ |
| 113 | Starting from 5.1 the Android linker warns about VERNEED (0x6FFFFFFE) and VERNEEDNUM (0x6FFFFFFF) ELF dynamic sections: |
| 114 | WARNING: linker: $BINARY: unused DT entry: type 0x6ffffffe arg ... |
| 115 | WARNING: linker: $BINARY: unused DT entry: type 0x6fffffff arg ... |
| 116 | These may come from version scripts in a Makefile such as: |
| 117 | -Wl,--version-script=$(top_srcdir)/proc/libprocps.sym |
| 118 | The termux-elf-cleaner utilty is run from build-package.sh and should normally take care of that problem. |
| 119 | |
| 120 | Obtaining shell access on an emulator |
| 121 | ===================================== |
| 122 | First install and start sshd on device: |
| 123 | apt install openssh |
| 124 | sshd |
| 125 | The follow the below steps: |
| 126 | # Find out the linux user for the package to use in the chown command later: |
| 127 | adb shell dumpsys package com.termux | grep userId= |
| 128 | # Push your public ssh key: |
| 129 | adb push $HOME/.ssh/id_dsa.pub /data/data/com.termux/files/home/.ssh/authorized_keys |
| 130 | # Use the linux user for the package, 10053 below, to set ownerhip and permissions: |
| 131 | adb shell chown -R 10053 /data/data/com.termux/files/home/.ssh/ |
| 132 | adb shell chmod -R 0700 /data/data/com.termux/files/home/.ssh/ |
| 133 | # Forward port 8022 to the emulator: |
| 134 | adb forward tcp:8022 tcp:8022 |
| 135 | # Finally connect with ssh: |
| 136 | ssh -p 8022 localhost |
| 137 | |
| 138 | Bootstrapping |
| 139 | ============= |
| 140 | To get files on device one option is: |
| 141 | udpsvd -vE 0.0.0.0 8069 tftpd -c . # Run on device. -c arg to allow file uploading |
| 142 | printf "mode binary\nput out.md\nquit" | tftp 192.168.0.12 8069 # on computer |
| 143 | Another is with ftp: |
| 144 | tcpsvd -vE 0.0.0.0 8021 ftpd -w . # Run on device. -w arg to allow file uploading |
| 145 | printf "put tmp.c\nquit" | ftp -n 192.168.0.12 8021 # Run on computer. -n arg to use anonymous login |
| 146 | NOTE: The ftpd and tftpd programs has been patched to run without chroot. This means that the directory |
| 147 | serving is only the starting point and clients may cd out of if the access the whole system! |
| 148 | |