Toolchain
Prebuilt toolchain
There're several options:
- Android Open Source Platform prebuilt snapshot. Click on the snapshot link to get a tar. It's about 74MB uncompressed.
- Android NDK
- Sourcery G++ arm eabi tool-chain
Assume you've chosen 1 since it is the best current option. After downloaded the toolchain to r:\prebuilt-*.tar.gz, execute:
tar xzf /mnt/r/prebuilt-*.tar.gz -C ~
A prebuilt folder will be created in user home.
Compiling your own toolchain from scratch
1. Download your device kernel, unpack this and create configs and headers:
make mapphone_defconfig make headers_install ARCH=arm INSTALL_HDR_PATH=~/build/kern_h/
You must know, what proccessor chip you have on target device, and set optimisation options from (http://gcc.gnu.org/onlinedocs/gcc-4.4.3/gcc/ARM-Options.html#ARM-Options) For example, if you have Motorola Milestone - so processor chip is TI OMAP3430 - ARM Cortex a8 (armv7a arch) (http://en.wikipedia.org/wiki/ARM_architecture) So you need use configs with -omap3430 suffix.
Also, I recommend use kernel-...configs instead of XVilka-...configs for creating toolchain for kernel building and hacking.
Set enviroment variable for building options:
export _XXCFLAGS=" -march=armv7-a -mtune=cortex-a8 -mfpu=neon" (if you have Milestone/Droid or other device on TI OMAP3430) export _XXCFLAGS=" -march=armv6j -mtune=arm1136jf-s" (if you have HTC Hero or other device on Quallcomm MSM 7200A)
2. Download crosstool-ng (http://ymorin.is-a-geek.org/dokuwiki/projects/crosstool), Unpack, build (you need for: make,install,bash,cut,sed,grep,gcc,awk,bison,flex,automake,libtool,stat, wget,cvs,patch,tar,gzip,bzip2,lzma,readlink,ncurses, mpfr-dev, gmp-dev)
.configure make make install
3. Create dir toolchain-android, cd to it and copy files: XVilka-crosstool-<suffix>.config in .config XVilka-uClibc-<suffix>.config in uClibc-0.9.30.2.config and then run:
ct-ng menuconfig
change anything, if you need, and save to .config then exec:
ct-ng build
4. Done! We have toolchain in build/x-tools. All tools have this triplet: arm-android-linux-uclibsgnueabi-* just add them in PATH
export PATH=$HOME/build/x-tools/arm-android-linux-uclibcgnueabi/bin:$PATH export CROSS_COMPILE=arm-android-linux-uclibcgnueabi- export KERNEL_CROSS_COMPILE=arm-android-linux-uclibcgnueabi-
So we can run arm-android-linux-uclibcgnueabi-gcc Also we have system root directory in: ~/build/x-tools/arm-android-linux-uclibcgnueabi/arm-android-linux-uclibcgnueabi/sys-root For some reasons we just copy it in ~/build/cross/sys-root
chmod +w sys-root chmod +w sys-root/usr chmod +w sys-root/usr/lib
Building and using tiny toolchain
For compiling some small hacking utility or kernel module you don need in whole gcc toolkit (more than 60 MB) and whole libc. So we need for something small and tiny. It can be tiny C compiler (tcc) and dietlibc You can download, unpack, copy bin files in /usr/local/bin, lib files in /usr/local/lib, tiny-root in $HOME/build. Link for downloading
If you want to know how i building it - read below:
For example we choose working directory as $HOME/build Download latest release of tiny C compiler (http://tinycc.org/) from git:
git clone git://repo.or.cz/tinycc.git $HOME/build/tinycc
Download latest release of dietlibc (http://www.fefe.de/dietlibc/) from cvs: <syntaxhiglight lang="bash"> cvs -d :pserver:cvs@cvs.fefe.de:/cvs -z9 co $HOME/build/dietlibc </syntaxhighlight> After this we need to build tcc:
cd $HOME/build/tinycc ./configure --enable-cross --prefix=$HOME/build/tiny-toolchain make make install
So we have this tools in $HOME/build/tiny-toolchain/bin:
arm-eabi-tcc arm-fpa-ld-tcc arm-fpa-tcc arm-vfp-tcc c67-tcc i386-win32-tcc tcc x86_64-tcc x86_64-win32-tcc
Add them in enviroment variable PATH for easy executing:
export PATH=$HOME/build/tiny-toolchain/bin:$PATH
But also we need a C library. So make the "target root" directory: <syntaxhiglight lang="bash"> mkdir $HOME/build/tiny-root </syntaxhighlight> Building dietlibc:
cd $HOME/build/dietlibc make prefix=$HOME/build/tiny-root make prefix=$HOME/build/tiny-root ARCH=arm CROSS=arm-android-linux-uclibcgnueabi- make install-headers prefix=$HOME/build/tiny-root ARCH=arm CROSS=arm-android-linux-uclibcgnueabi- make install-bin prefix=$HOME/build/tiny-root ARCH=arm CROSS=arm-android-linux-uclibcgnueabi-
Prepare "target root" directory:
ln -s $HOME/build/tiny-root/lib-arm $HOME/build/tiny-root/lib cp $HOME/build/tiny-toolchain/include/* $HOME/build/tiny-root/include/ cp $HOME/build/tiny-toolchain/lib/* $HOME/build/tiny-root/lib/
Also, for kernel development we need for kernel headers:
cd /path/to/you/kernel/sources make headers_install ARCH=arm INSTALL_HDR_PATH=$HOME/build/tiny-root/include
So, we have all needed libraries and headers in $HOME/build/tiny-root You can use tcc for compiling your small utilities, for example by this command:
arm-eabi-tcc -nostdinc -nostdlib -I$HOME/build/tiny-root/include -L$HOME/build/tiny-root/lib -o example example.c
Enjoy!