Cross compile per OpenMoko

Cross compile per OpenMoko

Per compilare un'applicazione per il FreeRunner su sistema operativo OpenMoko possiamo scegliere tre strade:

Qemu. È possibile eseguire l'intero sistema opertativo OpenMoko sotto Qemu, tuttavia l'hardware GTA02 (FreeRunner) non è pienamente supportato. Inoltre le utility fornite a corredo dell'emulatore sono scritte per il GTA01 (Neo1973), pertanto la strada per avere l'emulatore funzionante non è semplice. L'emulazione del GTA01/GTA02 non è inclusa nella distrubuzione ufficiale Qemu, bisogna scaricare i sorgenti dal repository SVN apposito.
MokoMakeFile. Si tratta di uno script che provvede a scaricare e configurare un ambiente completo derivato da OpenEmbedded. Il progetto è considerato obsoleto.
Toolchain. Questa è la strada consigliata sia per lo sviluppo di una singola applicazione che per un'intera distrubuzione. Consente di compilare codice arm su piattaforma i686 o amd64.

Installare la toolchain

Per installare la toolchain su Debian Lenny si sono seguite queste istruzioni: Openmoko application development in 5 minutes.

Si installano preventivamente i pacchetti:

apt-get install alien autoconf automake autotools-dev build-essential ccache check curl \
fakeroot gettext intltool libgconf2-dev libglib2.0-dev libtool libxrender-dev mtools uboot-mkimage

Si scarica la toolchain precompilata dal repository OpenMoko, esiste la versione i686 e amd64, il pacchetto non è rilocabile e va in /usr/local/openmoko. Invece di installare il tarball, lo si trasforma in uno pseudo pacchetto .deb facilmente (dis)installabile.

Scegliamo openmoko-i686-20090323-armv4t-linux-gnueabi-toolchain-openmoko.tar.bz2 (pacchetto per i686, per compilare codice arm su piattaforma GNU/Linux) ed eseguiamo:

bunzip2 openmoko-i686-20090323-armv4t-linux-gnueabi-toolchain-openmoko.tar.bz2
gzip openmoko-i686-20090323-armv4t-linux-gnueabi-toolchain-openmoko.tar
fakeroot alien -d openmoko-i686-20090323-armv4t-linux-gnueabi-toolchain-openmoko.tar.gz

Il pacchetto .deb risultante è installabile con

sudo dpkg -i openmoko-i686_20090323-2_all.deb

Usare la toolchain

Prima di compilare qualcosa si deve settare l'environment giusto (PATH, CPPFLAGS, CXXFLAGS, LDFLAGS, ecc.):

source /usr/local/openmoko/arm/environment-setup

Quindi si usa il compilatore apposito

arm-angstrom-linux-gnueabi-gcc -o test test.c

Un'ipotetico Makefile potrebbe contenere qualcosa del tipo:

export CC = arm-angstrom-linux-gnueabi-gcc
binary:
        $(CC) -o test test.c

Installazione delle dipendenze

Se il programma da compilare dipende da una libreria OpenMoko, bisogna installarla nella toolchain. Prima di tutto si deve impostare i repository da cui attingere in /usr/local/openmoko/arm/arm-angstrom-linux-gnueabi/etc/opkg.conf.

L'impostazione predefinita prevede di scaricare da unstable, ecco invece come scaricare i pacchetti da 2008.12:

arch all 1
src/gz all http://downloads.openmoko.org/repository/Om2008.8/all
arch armv4t 26
src/gz armv4t http://downloads.openmoko.org/repository/Om2008.8/armv4t
arch om-gta02 31
src/gz om-gta02 http://downloads.openmoko.org/repository/Om2008.8/om-gta02

Ecco l'esempio di come installare un pacchetto -dev:

. /usr/local/openmoko/arm/environment-setup
opkg-target update
opkg-target list
opkg-target install gpsd-dev

L'elenco dei pacchetti disponibili viene salvato in /usr/local/openmoko/arm/arm-angstrom-linux-gnueabi/usr/lib/opkg/lists/.
I pacchetti vengono installati sotto /usr/local/openmoko/arm/arm-angstrom-linux-gnueabi/.

Compiling a large project: Navit

Remember to improve the page Navit on FreeRunner.

How to cross-compile a large project like Navit for the OpenMoko/FreeRunner, using a GNU/Linux box and the toolchain.

First of all, edit the /usr/local/openmoko/arm/environment-setup script and add the followig line:

export OMTOOL_DIR=/usr/local/openmoko

After toolchain installation, install (with opkg-target) some OpenMoko -dev packages required to compile Navit. Depending upon permissions of /usr/local/openmoko/ directory, you may need root privileges:

. /usr/local/openmoko/arm/environment-setup
opkg-target list
opkg-target install gpsd-dev
opkg-target install gtk+-dev
opkg-target install libspeechd-dev

Now we check-out Navit sources from the SVN repository and we make an archive just in case we need the pristine sources in the future:

svn co https://navit.svn.sourceforge.net/svnroot/navit/trunk/navit
tar zcvf navit-svn-2670.tar.gz navit

Instead of running the traditional ./autogen.sh; ./configure in the navit source tree, we must run the om-conf script, which will modify the automake, autoconf and make files to run into the OpenMoko toolchain.

Because Navit on the OpenMoko FreeRunner requires some configure options, we will pass them to the script. Run om-conf from the directory containing the source tree (not inside it):

om-conf --host=arm-angstrom-linux-gnueabi --enable-avoid-unaligned --enable-avoid-float \
    --enable-cache-size=20971520 --with-saxon=saxon-xslt --with-xslts=openmoko \
    --enable-svg2png-scaling=16,32,48,96 --enable-svg2png-scaling-flag=32,48 \
    navit

In the example above we used some ./configure options, among them:

--with-saxon=saxon-xslt
This is because we have the Debian libsaxon-java package, where the executable is called saxon-xslt instead of saxon.

--enable-svg2png-scaling=16,32,48,96
For each .svg icon, render a png image of the specified size. Images will be named icon_XX_YY.png.

--enable-svg2png-scaling-flag=32,48
Same as above, but only for country flag icons.

It's time to cross-compile:

cd navit
make

Make an .opk package

Using the toolchains

The OpenMoko toolchain provides the om-make-ipkg utility. It requires the directory name where to execute the make install and the name of the control file:

. /usr/local/openmoko/arm/environment-setup
om-make-ipkg navit navit-control

The control file is described here.

If you need more control files (e.g. a postinst or alike) you have to tweak with the om-make-ipkg script. Here it is the script I use, it looks for the control files into an opkg directory, so you have to pass just the directory name containing the source tree.

#!/bin/sh -e
 
error_exit () {
        echo usage: $(basename ${0}) [app_dir_name] [ipkg_control_file]
        exit 1
}
 
test x${OMTOOL_DIR} = x && . /usr/local/openmoko/arm/setup-env
. ${OMTOOL_DIR}/arm/scripts/functions
S=${1}
(test x${S} = x || test ! -d ${S}) && error_exit
appname=$(basename ${S})
tmpdir=/tmp/${appname}-ipkg-tmp
test -e "${tmpdir}" && echo Cannot use ${tmpdir} because it already exists. && exit 1
make -C ${S} install DESTDIR="${tmpdir}"
# Copy control files to destination directory.
cp -pr opkg/* ${tmpdir}
ipkg-build -o 0 -g 0 ${tmpdir}
rm -rf ${tmpdir}

Control files and other files are arranged into the opkg directory as needed, here it is an example:

opkg/CONTROL/postinst
opkg/CONTROL/control
opkg/etc/rcS.d/S96overcommit_memory.sh

Using opkg-utils

The ipkg tool is obsolete, OpenMoko uses the opkg instead, but documentation is scarce.

The current opkg code is in Google code, but you can try this one:

svn co http://svn.openmoko.org/trunk/src/host/opkg-utils

and use the instructions of ipkg's website but the software from this checkout. The main script is opkg-build.

Qemu and the GTA02 FreeRunner

WARNING: this procedure works only for the GTA01 Neo1973, it fails for the GTA02 FreeRunner.

Install the Debian packages gcc-3.4 and libsdl1.2-dev, download the qemu-neo1973 sources from the svn repository. Run the ./configure && make.

Edit the openmoko/env file and set current URLs and filenames:

# Entries for GTA01
kernel_wildcard="uImage-2.6.22.5-moko11+svnr3238-r9-neo1973.bin"
rootfs_wildcard="openmoko-image-fic-gta01.jffs2"
uboot_wildcard="u-boot-gta01*.bin"
download_dir="http://downloads.openmoko.org/distro/obsolete-images/Om2007.11//images/neo1973/"

Run the openmoko/download.sh and openmoko/flash.sh scripts.

For the (failed) attempt to run the GTA02 FreeRunner emulator we need different Qemu parameters and different images:

qemu_relative="arm-softmmu/qemu-system-arm -M gta02fake -m 130"
# Entries for GTA02, Om2008.12
kernel_wildcard="Om2008.12-om-gta02.uImage.bin"
rootfs_wildcard="Om2008.12-om-gta02.rootfs.jffs2"
uboot_wildcard="gta02v5_and_up-u-boot.bin"
download_dir="http://downloads.openmoko.org/distro/releases/Om2008.12/"

The openmoko/Makefile should be changed so the openmoko-flash.base (the NAND image) will be 256 Mb in size:

# GTA02
$(FLASHIMG):
        # Making an empty/erased flash image.  Need a correct echo behavior.
        $(echo) -en \\0377\\0377\\0377\\0377\\0377\\0377\\0377\\0377 > .8b
        cat .8b .8b .8b .8b .8b .8b .8b .8b > .64b # OOB is 64 bytes
        cat .64b .64b .64b .64b .64b .64b .64b .64b >  .2048b
        cat .64b .64b .64b .64b .64b .64b .64b .64b >> .2048b
        cat .64b .64b .64b .64b .64b .64b .64b .64b >> .2048b
        cat .64b .64b .64b .64b .64b .64b .64b .64b >> .2048b
        cat .2048b .64b > .sec # A sector is 2048 bytes of data + OOB
        cat .sec .sec .sec .sec .sec .sec .sec .sec > .8sec
        cat .8sec .8sec .8sec .8sec .8sec .8sec .8sec .8sec > .64sec
        cat .64sec .64sec .64sec .64sec .64sec .64sec .64sec .64sec > .512sec
        cat .512sec .512sec .512sec .512sec > .2ksec
        cat .2ksec .2ksec .2ksec .2ksec .2ksec .2ksec .2ksec .2ksec > .16ksec
        # Neo GTA02 NAND is 128k sectors big
        cat .16ksec .16ksec .16ksec .16ksec .16ksec .16ksec .16ksec .16ksec > $@
        rm -rf .8b .64b .2048b .sec .8sec .64sec .512sec .2ksec .16ksec

The openmoko/download.sh will run, but openmoko/flash.sh fails with endless errors:

s3c_nand_read: Bad register 0x20

May be there are more instructions for the GTA02 in the wiki page.

We can manually run the emulator to get the U-Boot prompt, but here we have to partition and flash the NAND manually.

arm-softmmu/qemu-system-arm -M gta02fake -m 130 \
    -mtdblock openmoko-flash.base \
    -kernel u-boot.bin \
    -serial stdio -nographic -usb -monitor null

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