h1. Build a Native Developement Kit (NDK) with Replicant 4.2 h2. Principle of operation The [[ReplicantSourceCode|Android 4.2 source code]] ships a @ndk@ directory with NDK build scripts. These tools download various upstream imports from https://xxx/toolchain/XXX/ https://android.googlesource.com/toolchain/XXX/ with optional commit date (no branches or tags), apply patches, and build them. Note: as of 2015-07, the upcoming Android version moved to a different build system, and will populate $topdir/toolchain/ through @repo@ instead of invoking git in a temporary directory (i.e. ditched @download-toolchain-sources.sh@). h2. Ubuntu 12.04 build environment with LXC Replicant 4.2 is based on CyanogenMod 10.1 which is based on AOSP 4.2.2 (2013-02). The build environment used by NDK release managers should be Ubuntu LTS 12.04. We recreate it through LXC. If you know how to use Triskel 6 instead, please contribute the instructions. <pre> lxc-create -n replicant -t download -- -d ubuntu -r precise -a amd64 # Note: or Triskel 6, if you know how to configure LXC/debootstrap for it lxc-start -n replicant -d lxc-attach -n replicant # clean-up non-free sources sed -i -e 's/ restricted//' -e 's/ multiverse//' /etc/apt/sources.list apt-get update # prepare build user apt-get install openssh-server useradd replicant --shell /bin/bash --create-home mkdir -p -m 700 ~replicant/.ssh cat <<EOF >> ~replicant/.ssh/authorized_keys your public key EOF chown -R replicant: ~replicant </pre> Note: compiling from Debian 8 will yield errors from texinfo (doc in binutils) and Perl (POD in LLVM) due to more recent, stricter versions of these. h2. Build dependencies <pre> # Base Android build dependencies (from https://source.android.com/source/initializing.html, section "Installing required packages (Ubuntu 12.04)") # Dropping mingw to skip windows builds for now. # Installing g++-multilib first otherwise apt-get complains. apt-get install build-essential g++-multilib apt-get install git gnupg flex bison gperf \ zip curl libc6-dev libncurses5-dev:i386 x11proto-core-dev \ libx11-dev:i386 libreadline6-dev:i386 libgl1-mesa-glx:i386 \ libgl1-mesa-dev \ python-markdown libxml2-utils xsltproc zlib1g-dev:i386 # Additional NDK build dependencies (completed from https://android.googlesource.com/platform/ndk/+/master/README.md) apt-get install curl texinfo bison flex libtool pbzip2 groff # Make 'bash' the default shell otherwise 'build-gabi++.sh' will fail dpkg-reconfigure dash </pre> h2. Preparing the sources Based on [[ReplicantSourceCode]] with additional configuration. <pre> mkdir ~/tools/ cd ~/tools/ wget http://commondatastorage.googleapis.com/git-repo-downloads/repo chmod a+x repo cd ~ cat <<EOF >> ~/.bashrc export USE_CCACHE=1 EOF # Avoid prompts git config --global user.email "email@example.com" git config --global user.name "Your Name" git config --global color.ui true mkdir replicant-4.2/ cd replicant-4.2/ ../tools/repo init -u git://git.replicant.us/manifest.git -b replicant-4.2 ../tools/repo sync -j4 # > 1h, 27GB (inc. 17GB .repo) </pre> h2. Determining the checkout date Since there's no NDK release tag for the @toolchain/@ Git checkouts, we need to find the right date. @cd ndk/ && git log@ says the last commit is 2012-10-05, so it's around NDK r8b (2012-07) and NDK r8c (2012-11). Checking @build/tools/toolchain-patches/@ in the NDKs shows r8c has matching patches. Also NDKs from google contain several @SOURCES@ files listing Git repos and commit IDs. With r8c's release date (@ls --full-time RELEASE.TXT@), @build/tools/download-toolchain-sources.sh@ checkouts the same Git commit IDs, and the patches apply. Only, r8c references a LLVM Git repo, while our scripts download a tarball. So our scripts match a NDK version between r8b and r8c, and can almost exactly reproduce r8c. Let's call it r8b2. h2. Building the SDK Based on @ndk/docs/DEVELOPMENT.html@, with much improvement :) <pre> export NDK=~/replicant-4.2/ndk cd $NDK # Allow checking build errors export NDK_LOGFILE=$HOME/ndk.log # Follow Python download redirection sed -i -e 's/curl -S/curl -L -S/' build/tools/download-toolchain-sources.sh # Get the sources from toolchain/ repos, with r8c release date: bash $NDK/build/tools/download-toolchain-sources.sh --git-date='2012-10-22T07:59:40+0200' ~/ndk-dl # ndk-dl: 2.5GB # Define NDK_TMPDIR and and use --incremental so the build can be resumed on error export NDK_TMPDIR=~/ndk-tmp mkdir -p $NDK_TMPDIR/release-r8b2/ # Build the release bash $NDK/build/tools/make-release.sh --toolchain-src-dir=$HOME/ndk-dl --release=r8b2 --incremental # 30mn with 4 cores, 28GB (inc. 17GB .repo), 2.5GB ndk-dl, 1GB /tmp </pre> The GNU/Linux NDK release is in @/tmp/ndk-replicant/release/android-ndk-r8b2-linux-x86.tar.bz2@ :) h2. TODOs h3. Mirror @toolchain/@ repos @download-toolchain-sources.sh@'s default is @--git-base=https://android.googlesource.com/toolchain@. Should we use a git.replicant.us repo? (note: there's no 'toolchain' there yet) h3. Windows build Build deps: <pre> # windows build is triggered by the presence of mingw32 apt-get install mingw32 tofrodos # and requires running maketab.exe apt-get install wine # I had troubles in LXC registering direct .exe execution: # $ /tmp/ndk-replicant/tmp/build-3038/maketab.exe # run-detectors: unable to find an interpreter for /tmp/ndk-replicant/tmp/build-3038/maketab.exe # Work-around: update-binfmts --disable dpkg-reconfigure wine1.4 --pri=high </pre> Code fixes: <pre> # build-ndk-stack/elff/ produces a warning with mingw32, and uses -Werror # cf. https://android.googlesource.com/platform/ndk/+/32e74f3f1b969ff65f037e1ee89e21a5cbc0ecf0 sed -i -e 's/-Werror//' sources/host-tools/ndk-stack/GNUMakefile # TODO: maybe 'export EXTRA_CFLAGS=-Wall' would be enough? # TODO: does this mean google was rebuilding from Ubuntu 10.04 instead of 12.04? </pre> ... <pre> bash $NDK/build/tools/make-release.sh --toolchain-src-dir=$HOME/ndk-dl --release=r8b2 --incremental # /home/replicant/ndk-dl/build/../binutils/binutils-2.21/gold/arm.cc:2171: internal compiler error: in make_rtl_for_nonlocal_decl, at cp/decl.c:4971 # => let's disable the windows build for now.. maybe better with 10.04? or a later ndk.git revision? </pre> h3. Use of prebuilts Check how much of $topdir/prebuilts/ is used to compile the NDK. We shouldn't rely on untrusted binaries. h3. Other build method Attempt to rebuild r8e with the same build environment, but checkout-ing precise .git revisions from ndk.git and development.git: less patches + local LLVM repo + precise control over the ndk scripts revision According to @ndk/docs/DEVELOPMENT.html@ one only needs: git clone https://xxx/platform/ndk.git ndk git clone https://xxx/platform/development.git development This means we wouldn't rely on exactly the build scripts shipped in Replicant 4.2. h4. Yet another build method @ndk/docs/DEVELOPMENT.html@ references using an existing (trusted) NDK to build the next one.