One of the big advantages of using Linux in embedded systems is the thousands of applications and drivers available for it (http://bec-systems.com/web/content/view/35/37/ ). One of the challenges of Embedded Linux is building these applications. Building applications for an embedded system often involves cross-compiling which is frustrating on a good day. This article details how to use OpenEmbedded (OE) with the existing toolchain Moxa provides to build a number of applications for the Moxa UC7408.
Web Application Support
My needs for this project were to build a web application that ran on the UC7408 (See http://bec-systems.com/web/content/view/55/9/ for a review of the Moxa UC7408). The Moxa firmware is fairly full featured and provides php for web application development. This is probably fine for many applications, but I prefer to build web applications as detailed in this article: http://bec-systems.com/web/content/view/46/9/ . Because the rest of the application is written in Python, there are advantages to also implementing the web application in Python. I also wanted to use the sqlite database. A quick look at the php supplied with the Moxa firmware suggested it was built without sqlite support. In summary, I needed the following components:
- Python
- Clearsilver
- sqlite
- minicom
- vim
- strace
- subversion
- wget
The above is a fairly small list, but what you don’t see are all the dependencies that also need to be built and installed. This ends up being many more components. Some of the items are for development only, but this is Linux — why not have nice tools running on the target system?
OE to the rescue
Ideally, the Moxa system would have a complete root file system built with OE running on it. But I did not have the time or budget to implement this, so I did the next best thing — use the rootfs and toolchain supplied by Moxa along with OE to compile just the applications I needed. Typically, OE builds the toolchain and Glibc, but fortunately OE provides a very slick way to use an external toolchain and glibc with OE. How to do this is detailed in the OE manual: http://www.openembedded.org/user-manual&dpage=commonuse_prebuilt_toolchain. Below is the setup I used:
Environment variables:
TOOLCHAIN=/usr/local/mxscaleb/bin/
export PRE_BUILT=/usr/local/mxscaleb/armv5b-linux
export CCACHE_DIR="${TOPDIR}/ccache"
export PYTHONPATH="${TOPDIR}/bitbake/lib"
export BBPATH="${TOPDIR}:${TOPDIR}/openembedded:${TOPDIR}/bitbake"
export PATH="${TOPDIR}/bitbake/bin:${TOOLCHAIN}:${PATH}"
export LD_LIBRARY_PATH=
export LANG=C
Local.conf file:
DL_DIR = "/build/sva_oe/downloads"
BBFILES := "/build/sva_oe/openembedded/packages/*/*.bb"
BBMASK = ""
PREFERRED_PROVIDERS = "virtual/qte:qte virtual/libqpe:libqpe-opie"
PREFERRED_PROVIDERS += " virtual/libsdl:libsdl-qpe"
PREFERRED_PROVIDERS += " virtual/${TARGET_PREFIX}gcc-initial:gcc-cross-initial"
PREFERRED_PROVIDERS += " virtual/${TARGET_PREFIX}gcc:gcc-cross"
PREFERRED_PROVIDERS += " virtual/${TARGET_PREFIX}g++:gcc-cross"
PREFERRED_PROVIDER_virtual/libx11 = "diet-x11"
ASSUME_PROVIDED += " virtual/${TARGET_PREFIX}gcc "
ASSUME_PROVIDED += " virtual/libc "
MACHINE = "moxa"
IPKG_ARCHS = "all arm armv4 armv5te xscale ${MACHINE}"
TARGET_CC_ARCH = "-mcpu=xscale"
TARGET_ARCH = "arm"
PACKAGE_ARCH="xscale"
TARGET_OS = "linux"
TARGET_FPU = "soft"
DISTRO = "moxa-disro"
DISTRO_NAME = "moxa-distro"
DISTRO_VERSION = "0.0.1"
DISTRO_TYPE = "release"
INHERIT += " package_ipk package_tar debian"
IMAGE_FSTYPES = "jffs2 tar"
PARALLEL_MAKE = "-j 4"
BBINCLUDELOGS = "yes"
CVS_TARBALL_STASH = "http://www.oesources.org/source/current/"
export CC = "mxscaleb-gcc-3.3.2 ${HOST_CC_ARCH}"
export CXX = "mxscaleb-g++ ${HOST_CC_ARCH}"
export CPP = "mxscaleb-gcc-3.3.2 -E"
export LD = "mxscaleb-ld"
export AR = "mxscaleb-ar"
export AS = "mxscaleb-as"
export RANLIB = "mxscaleb-ranlib"
export STRIP = "mxscaleb-strip"
TARGET_CPPFLAGS_append = " -I${PRE_BUILT}/include "
TARGET_LDFLAGS_prepend = " -L${PRE_BUILT}/lib -Wl,-rpath-link, ...
${PRE_BUILT}/lib -Wl,-rpath-link,${PRE_BUILT}/qt2/lib "
With the above setup, I was able to build the applications I needed with very little effort. There were a few little problems I ran into, but I was able to quickly work around them. The result is a number of packages that can be installed on the target system:
bigreqsproto-dev-X11R7.0-1.0.2-r0.tar.gz python-crypt-2.4.3-ml0.tar.gz busybox-1.2.1-r1.3.tar.gz python-curses-2.4.3-ml1.tar.gz busybox-udhcpd-1.2.1-r1.3.tar.gz python-datetime-2.4.3-ml0.tar.gz clearsilver-0.10.3-r0.tar.gz python-db-2.4.3-ml0.tar.gz clearsilver-dbg-0.10.3-r0.tar.gz python-devel-2.4.3-ml0.tar.gz clearsilver-dev-0.10.3-r0.tar.gz python-distutils-2.4.3-ml0.tar.gz clearsilver-doc-0.10.3-r0.tar.gz python-email-2.4.3-ml0.tar.gz inputproto-dev-X11R7.0-1.3.2-r0.tar.gz python-fcntl-2.4.3-ml0.tar.gz ipkg-0.99.163-r1.tar.gz python-gdbm-2.4.3-ml0.tar.gz ipkg-dbg-0.99.163-r1.tar.gz python-hotshot-2.4.3-ml0.tar.gz ipkg-dev-0.99.163-r1.tar.gz python-html-2.4.3-ml0.tar.gz kbproto-dev-X11R7.1-1.0.3-r0.tar.gz python-idle-2.4.3-ml0.tar.gz libapr-0-0-0.9.12-r0.tar.gz python-image-2.4.3-ml0.tar.gz libapr-0-bin-0.9.12-r0.tar.gz python-io-2.4.3-ml0.tar.gz libapr-0-dev-0.9.12-r0.tar.gz python-lang-2.4.3-ml0.tar.gz libaprutil-0-0-0.9.12-r0.tar.gz python-lib-old-and-deprecated-2.4.3-ml0.tar.gz libaprutil-0-bin-0.9.12-r0.tar.gz python-logging-2.4.3-ml0.tar.gz libaprutil-0-dev-0.9.12-r0.tar.gz python-mailbox-2.4.3-ml0.tar.gz libcrypto0.9.7-0.9.7g-r1.tar.gz python-math-2.4.3-ml0.tar.gz libexpat-bin-2.0.0-r1.tar.gz python-mime-2.4.3-ml0.tar.gz libexpat-dev-2.0.0-r1.tar.gz python-mmap-2.4.3-ml0.tar.gz libexpat-doc-2.0.0-r1.tar.gz python-netclient-2.4.3-ml1.tar.gz libexpat1-2.0.0-r1.tar.gz python-netserver-2.4.3-ml0.tar.gz libgcrypt-dbg-1.2.2-r0.tar.gz python-pickle-2.4.3-ml0.tar.gz libgcrypt-dev-1.2.2-r0.tar.gz python-pprint-2.4.3-ml0.tar.gz libgcrypt-doc-1.2.2-r0.tar.gz python-profile-2.4.3-ml0.tar.gz libgcrypt11-1.2.2-r0.tar.gz python-pydoc-2.4.3-ml0.tar.gz libgdbm-dbg-1.8.3-r2.tar.gz python-pyserial-2.2-r1.tar.gz libgdbm-dev-1.8.3-r2.tar.gz python-pysqlite2-2.2.2-ml1.tar.gz libgdbm-doc-1.8.3-r2.tar.gz python-pyxml-0.8.4-ml0.tar.gz libgdbm3-1.8.3-r2.tar.gz python-re-2.4.3-ml0.tar.gz libgnutls-bin-1.4.0-r1.tar.gz python-readline-2.4.3-ml0.tar.gz libgnutls-dbg-1.4.0-r1.tar.gz python-resource-2.4.3-ml0.tar.gz libgnutls-dev-1.4.0-r1.tar.gz python-shell-2.4.3-ml0.tar.gz libgnutls-doc-1.4.0-r1.tar.gz python-stringold-2.4.3-ml0.tar.gz libgnutls-extra13-1.4.0-r1.tar.gz python-subprocess-2.4.3-ml0.tar.gz libgnutls-locale-en+boldquot-1.4.0-r1.tar.gz python-syslog-2.4.3-ml0.tar.gz libgnutls-locale-en+quot-1.4.0-r1.tar.gz python-terminal-2.4.3-ml0.tar.gz libgnutls-locale-pl-1.4.0-r1.tar.gz python-tests-2.4.3-ml0.tar.gz libgnutls-openssl13-1.4.0-r1.tar.gz python-textutils-2.4.3-ml0.tar.gz libgnutls13-1.4.0-r1.tar.gz python-threading-2.4.3-ml0.tar.gz libgpg-error-dbg-1.3-r1.tar.gz python-tkinter-2.4.3-ml0.tar.gz libgpg-error-dev-1.3-r1.tar.gz python-unittest-2.4.3-ml0.tar.gz libgpg-error-locale-de-1.3-r1.tar.gz python-unixadmin-2.4.3-ml0.tar.gz libgpg-error-locale-fr-1.3-r1.tar.gz python-xml-2.4.3-ml0.tar.gz libgpg-error-locale-pl-1.3-r1.tar.gz python-xmlrpc-2.4.3-ml0.tar.gz libgpg-error-locale-ro-1.3-r1.tar.gz python-zlib-2.4.3-ml1.tar.gz libgpg-error-locale-vi-1.3-r1.tar.gz sqlite3-3.3.7-r2.tar.gz libgpg-error0-1.3-r1.tar.gz sqlite3-dbg-3.3.7-r2.tar.gz libice-dbg-X11R7.1-1.0.1-r0.tar.gz strace-4.5.14-r3.tar.gz libice-dev-X11R7.1-1.0.1-r0.tar.gz strace-dbg-4.5.14-r3.tar.gz libice6-X11R7.1-1.0.1-r0.tar.gz strace-doc-4.5.14-r3.tar.gz libipkg-dev-0.99.163-r1.tar.gz subversion-1.3.1-r1.tar.gz libipkg0-0.99.163-r1.tar.gz subversion-dbg-1.3.1-r1.tar.gz liblzo-dbg-1.08-r14.tar.gz subversion-dev-1.3.1-r1.tar.gz liblzo-dev-1.08-r14.tar.gz subversion-doc-1.3.1-r1.tar.gz liblzo1-1.08-r14.tar.gz subversion-locale-de-1.3.1-r1.tar.gz libneon-bin-0.25.5-r0.tar.gz subversion-locale-es-1.3.1-r1.tar.gz libneon-dev-0.25.5-r0.tar.gz subversion-locale-fr-1.3.1-r1.tar.gz libneon-doc-0.25.5-r0.tar.gz subversion-locale-it-1.3.1-r1.tar.gz libneon25-0.25.5-r0.tar.gz subversion-locale-ja-1.3.1-r1.tar.gz libpython2.4-1.0-2.4.3-ml5.tar.gz subversion-locale-ko-1.3.1-r1.tar.gz libreadline-dbg-4.3-r3.tar.gz subversion-locale-nb-1.3.1-r1.tar.gz libreadline-dev-4.3-r3.tar.gz subversion-locale-pl-1.3.1-r1.tar.gz libreadline-doc-4.3-r3.tar.gz subversion-locale-pt-br-1.3.1-r1.tar.gz libreadline4-4.3-r3.tar.gz subversion-locale-sv-1.3.1-r1.tar.gz libsm-dbg-X11R7.1-1.0.1-r0.tar.gz subversion-locale-zh-cn-1.3.1-r1.tar.gz libsm-dev-X11R7.1-1.0.1-r0.tar.gz subversion-locale-zh-tw-1.3.1-r1.tar.gz libsm6-X11R7.1-1.0.1-r0.tar.gz tcl-8.4.11-r3.tar.gz libsqlite-bin-2.8.17-r2.tar.gz tcl-dbg-8.4.11-r3.tar.gz libsqlite-dbg-2.8.17-r2.tar.gz tcl-dev-8.4.11-r3.tar.gz libsqlite-dev-2.8.17-r2.tar.gz tcl-doc-8.4.11-r3.tar.gz libsqlite0-2.8.17-r2.tar.gz time-1.7-r0.tar.gz libsqlite3-0-3.3.7-r2.tar.gz time-dbg-1.7-r0.tar.gz libsqlite3-dev-3.3.7-r2.tar.gz time-doc-1.7-r0.tar.gz libssl0.9.7-0.9.7g-r1.tar.gz tmp libx11-6-X11R7.1-1.0.1-r1.tar.gz update-rc.d-0.7-r0.tar.gz libx11-dbg-X11R7.1-1.0.1-r1.tar.gz util-macros-dev-X11R7.1-1.0.2-r0.tar.gz libx11-dev-X11R7.1-1.0.1-r1.tar.gz vim-7.0-r0.tar.gz libx11-doc-X11R7.1-1.0.1-r1.tar.gz vim-doc-7.0-r0.tar.gz libx11-locale-X11R7.1-1.0.1-r1.tar.gz vim-help-7.0-r0.tar.gz libxau-dbg-X11R7.1-1.0.1-r0.tar.gz vim-syntax-7.0-r0.tar.gz libxau-dev-X11R7.1-1.0.1-r0.tar.gz vim-tutor-7.0-r0.tar.gz libxau-doc-X11R7.1-1.0.1-r0.tar.gz wget-1.9.1-r6.tar.gz libxau6-X11R7.1-1.0.1-r0.tar.gz wget-dbg-1.9.1-r6.tar.gz libxdmcp-dbg-X11R7.1-1.0.1-r0.tar.gz wget-doc-1.9.1-r6.tar.gz libxdmcp-dev-X11R7.1-1.0.1-r0.tar.gz wget-locale-bg-1.9.1-r6.tar.gz libxdmcp6-X11R7.1-1.0.1-r0.tar.gz wget-locale-ca-1.9.1-r6.tar.gz libxml2-2.6.22-r3.tar.gz wget-locale-cs-1.9.1-r6.tar.gz libxml2-dbg-2.6.22-r3.tar.gz wget-locale-da-1.9.1-r6.tar.gz libxml2-dev-2.6.22-r3.tar.gz wget-locale-de-1.9.1-r6.tar.gz libxml2-doc-2.6.22-r3.tar.gz wget-locale-el-1.9.1-r6.tar.gz libxml2-utils-2.6.22-r3.tar.gz wget-locale-es-1.9.1-r6.tar.gz libxt-dbg-X11R7.1-1.0.2-r0.tar.gz wget-locale-et-1.9.1-r6.tar.gz libxt-dev-X11R7.1-1.0.2-r0.tar.gz wget-locale-fr-1.9.1-r6.tar.gz libxt-doc-X11R7.1-1.0.2-r0.tar.gz wget-locale-gl-1.9.1-r6.tar.gz libxt6-X11R7.1-1.0.2-r0.tar.gz wget-locale-he-1.9.1-r6.tar.gz libz-dbg-1.2.3-r1.tar.gz wget-locale-hr-1.9.1-r6.tar.gz libz-dev-1.2.3-r1.tar.gz wget-locale-hu-1.9.1-r6.tar.gz libz1-1.2.3-r1.tar.gz wget-locale-it-1.9.1-r6.tar.gz minicom-2.1-r0.tar.gz wget-locale-ja-1.9.1-r6.tar.gz minicom-dbg-2.1-r0.tar.gz wget-locale-nl-1.9.1-r6.tar.gz minicom-doc-2.1-r0.tar.gz wget-locale-no-1.9.1-r6.tar.gz ncurses-5.4-r8.tar.gz wget-locale-pl-1.9.1-r6.tar.gz ncurses-dbg-5.4-r8.tar.gz wget-locale-pt-br-1.9.1-r6.tar.gz ncurses-dev-5.4-r8.tar.gz wget-locale-ro-1.9.1-r6.tar.gz ncurses-doc-5.4-r8.tar.gz wget-locale-ru-1.9.1-r6.tar.gz ncurses-terminfo-5.4-r8.tar.gz wget-locale-sk-1.9.1-r6.tar.gz ncurses-tools-5.4-r8.tar.gz wget-locale-sl-1.9.1-r6.tar.gz openssl-0.9.7g-r1.tar.gz wget-locale-sv-1.9.1-r6.tar.gz openssl-dbg-0.9.7g-r1.tar.gz wget-locale-tr-1.9.1-r6.tar.gz openssl-dev-0.9.7g-r1.tar.gz wget-locale-uk-1.9.1-r6.tar.gz openssl-doc-0.9.7g-r1.tar.gz wget-locale-zh-cn-1.9.1-r6.tar.gz python-audio-2.4.3-ml0.tar.gz wget-locale-zh-tw-1.9.1-r6.tar.gz python-bsddb-2.4.3-ml0.tar.gz xcmiscproto-dev-X11R7.0-1.1.2-r0.tar.gz python-codecs-2.4.3-ml0.tar.gz xextproto-dev-X11R7.0-7.0.2-r0.tar.gz python-compile-2.4.3-ml0.tar.gz xf86bigfontproto-dev-X11R7.0-1.1.2-r0.tar.gz python-compiler-2.4.3-ml0.tar.gz xproto-dev-X11R7.1-7.0.5-r0.tar.gz python-compression-2.4.3-ml0.tar.gz xtrans-dev-X11R7.0-1.0.0-r1.tar.gz python-core-2.4.3-ml1.tar.gz
Installing the needed packages is just a matter of uncompressing a subset of the above files on the target system.
Summary
This exercise demonstrates how a developer can quickly (took me less than 4 hours) add a large number of applications (and dependencies) to about any Embedded Linux system. Leveraging embedded Linux is being able to use the components you need. Please contact us if you would like additional details or assistance.
Have you tried this for the newer Moxa UC-84xx series at all?
No, I have not. The UC-84xx look like very interesting products, and as they are based on the same CPU (IXP4xx), it may work.
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