How to setup a development environment
From IGEP - ISEE Wiki
This tutorial was written for the igep revB board, but it is transposable to other OMAP3530 boards (above all for the DSP part). It is a summary (with some adaptations) of several tutorials found on Internet (see References). All files will be installed in the $HOME directory.
This tutorial is a translation of a French tutorial we wrote on our robotic web site. Sorry for the English, fill free to correct mistakes.
Contents
Rootfs
This section describes how to obtain the Poky distribution. This is the distribution shipped with the igep boad; it is based on Open Embedded.
The first thing to do is set Bash as default sh shell:
sudo dpkg-reconfigure dash
answer no to the question. Thus, "/bin/sh" will point towards "/bin/bash" (and not "/bin/dash"). Then, some kernels settings have to be changed. Edit the file "/etc/sysctl.conf" as root and set :
vm.mmap_min_addr = 0
then, to take the modification into account:
sudo sysctl -p
Some additional packages need to be installed to satisfy bitbake dependencies. First, add the following repositories to "/etc/apt/sources.list" :
deb http://debian.o-hand.com etch/ deb http://debian.o-hand.com unstable/ deb http://debian.o-hand.com feisty/ deb http://debian.o-hand.com gutsy/ deb http://debian.o-hand.com hardy/
Update the data base and install the following packages:
sudo apt-get update sudo aptitude install python-psyco hgsvn qemu poky-depends poky-scripts
Then, download and decompress the last stable version of Poky:
mkdir -p $HOME/igep/poky cd $HOME/igep/poky wget http://pokylinux.org/releases/poky-purple-3.2.tar.bz2 tar -xjf poky-purple-3.2.tar.bz2
The configuration file of Poky is located in the directory $HOME/igep/poky/build/conf :
cd build/conf nano local.conf
And paste the modified version for the igep board:
# Where to cache the files Poky downloads
DL_DIR ?= "${OEROOT}/sources"
BBFILES += "\
${OEROOT}/meta/packages/*/*.bb \
${OEROOT}/meta-moblin/packages/*/*.bb"
BBFILE_COLLECTIONS = "normal moblin"
BBFILE_PATTERN_normal = "^${OEROOT}/meta/"
BBFILE_PATTERN_moblin = "^${OEROOT}/meta-moblin/"
BBFILE_PRIORITY_normal = "5"
BBFILE_PRIORITY_moblin = "5"
# Uncomment and set to allow bitbake to execute multiple tasks at once.
# For a quadcore, BB_NUMBER_THREADS = "4", PARALLEL_MAKE = "-j 4" would
# be appropriate.
# BB_NUMBER_THREADS = "2"
# Also, make can be passed flags so it run parallel threads e.g.:
# PARALLEL_MAKE = "-j 2"
# The machine to target
MACHINE ?= "igep0020b"
TARGET_FPU_arm ?= "hard"
# Other supported machines
#MACHINE ?= "qemux86"
#MACHINE ?= "qemuarm"
#MACHINE ?= "c7x0"
#MACHINE ?= "akita"
#MACHINE ?= "spitz"
#MACHINE ?= "nokia770"
#MACHINE ?= "nokia800"
#MACHINE ?= "fic-gta01"
#MACHINE ?= "bootcdx86"
#MACHINE ?= "cm-x270"
#MACHINE ?= "em-x270"
#MACHINE ?= "htcuniversal"
#MACHINE ?= "mx31ads"
#MACHINE ?= "mx31litekit"
#MACHINE ?= "mx31phy"
#MACHINE ?= "netbook"
#MACHINE ?= "zylonite"
DISTRO ?= "poky"
# For bleeding edge / experimental / unstable package versions
# DISTRO ?= "poky-bleeding"
# Poky has various extra metadata collections (openmoko, extras).
# To enable these, uncomment all (or some of) the following lines:
# BBFILES = "\
# ${OEROOT}/meta/packages/*/*.bb \
# ${OEROOT}/meta-extras/packages/*/*.bb \
# ${OEROOT}/meta-openmoko/packages/*/*.bb \
# ${OEROOT}/meta-moblin/packages/*/*.bb \
# "
# BBFILE_COLLECTIONS = "normal extras openmoko moblin"
# BBFILE_PATTERN_normal = "^${OEROOT}/meta/"
# BBFILE_PATTERN_extras = "^${OEROOT}/meta-extras/"
# BBFILE_PATTERN_openmoko = "^${OEROOT}/meta-openmoko/"
# BBFILE_PATTERN_moblin = "^${OEROOT}/meta-moblin/"
# BBFILE_PRIORITY_normal = "5"
# BBFILE_PRIORITY_extras = "5"
# BBFILE_PRIORITY_openmoko = "5"
# BBFILE_PRIORITY_moblin = "5"
BBMASK = ""
# EXTRA_IMAGE_FEATURES allows extra packages to be added to the generated images
# (Some of these are automatically added to certain image types)
# "dbg-pkgs" - add -dbg packages for all installed packages
# (adds symbol information for debugging/profiling)
# "dev-pkgs" - add -dev packages for all installed packages
# (useful if you want to develop against libs in the image)
# "tools-sdk" - add development tools (gcc, make, pkgconfig etc.)
# "tools-debug" - add debugging tools (gdb, strace)
# "tools-profile" - add profiling tools (oprofile, exmap, lttng valgrind (x86 only))
# "tools-testapps" - add useful testing tools (ts_print, aplay, arecord etc.)
# "debug-tweaks" - make an image for suitable of development
# e.g. ssh root access has a blank password
# There are other application targets too, see meta/classes/poky-image.bbclass
# and meta/packages/tasks/task-poky.bb for more details.
EXTRA_IMAGE_FEATURES = "tools-debug tools-profile tools-testapps debug-tweaks"
# The default IMAGE_FEATURES above are too large for the mx31phy and
# c700/c750 machines which have limited space. The code below limits
# the default features for those machines.
EXTRA_IMAGE_FEATURES_c7x0 = "tools-testapps debug-tweaks"
EXTRA_IMAGE_FEATURES_mx31phy = "debug-tweaks"
EXTRA_IMAGE_FEATURES_mx31ads = "tools-testapps debug-tweaks"
# A list of packaging systems used in generated images
# The first package type listed will be used for rootfs generation
# include 'package_deb' for debs
# include 'package_ipk' for ipks
#PACKAGE_CLASSES ?= "package_deb package_ipk"
PACKAGE_CLASSES ?= "package_ipk"
# POKYMODE controls the characteristics of the generated packages/images by
# telling poky which type of toolchain to use.
#
# Options include several different EABI combinations and a compatibility
# mode for the OABI mode poky previously used.
#
# The default is "eabi"
# Use "oabi" for machines with kernels < 2.6.18 on ARM for example.
# Use "external-MODE" to use the precompiled external toolchains where MODE
# is the type of external toolchain to use e.g. eabi.
# POKYMODE = "external-eabi"
# Uncomment this to specify where BitBake should create its temporary files.
# Note that a full build of everything in OpenEmbedded will take GigaBytes of hard
# disk space, so make sure to free enough space. The default TMPDIR is
# <build directory>/tmp
TMPDIR = "${OEROOT}/build/tmp-${MACHINE}"
# Uncomment this if you are using the Openedhand provided qemu deb - see README
ASSUME_PROVIDED += "qemu-native"
# Comment this out if you don't have a 3.x gcc version available and wish
# poky to build one for you. The 3.x gcc is required to build qemu-native.
#ASSUME_PROVIDED += "gcc3-native"
# Uncomment these two if you want BitBake to build images useful for debugging.
# DEBUG_BUILD = "1"
# INHIBIT_PACKAGE_STRIP = "1"
# Uncomment these to build a package such that you can use gprof to profile it.
# NOTE: This will only work with 'linux' targets, not
# 'linux-uclibc', as uClibc doesn't provide the necessary
# object files. Also, don't build glibc itself with these
# flags, or it'll fail to build.
#
# PROFILE_OPTIMIZATION = "-pg"
# SELECTED_OPTIMIZATION = "${PROFILE_OPTIMIZATION}"
# LDFLAGS =+ "-pg"
# Uncomment this if you want BitBake to emit debugging output
# BBDEBUG = "yes"
# Uncomment this if you want BitBake to emit the log if a build fails.
BBINCLUDELOGS = "yes"
# Specifies a location to search for pre-generated tarballs when fetching
# a cvs:// or svn:// URI. Uncomment this, if you do not want to pull directly
# from CVS or Subversion
SRC_TARBALL_STASH = "http://pokylinux.org/sources/"
# Set this if you wish to make pkgconfig libraries from your system available
# for native builds. Combined with extra ASSUME_PROVIDEDs this can allow
# native builds of applications like oprofileui-native (unsupported feature).
#EXTRA_NATIVE_PKGCONFIG_PATH = ":/usr/lib/pkgconfig"
#ASSUME_PROVIDED += "gtk+-native libglade-native"
ENABLE_BINARY_LOCALE_GENERATION = "0"
# The architecture to build SDK items for, by setting this you can build SDK
# packages for architectures other than the host i.e. building i586 packages
# on an x86_64 host.
# Supported values are i586 and x86_64
SDKMACHINE="i586"
The following section needs to be adapted to the number of CPU the host machine has:
# Uncomment and set to allow bitbake to execute multiple tasks at once. # For a quadcore, BB_NUMBER_THREADS = "4", PARALLEL_MAKE = "-j 4" would # be appropriate. # BB_NUMBER_THREADS = "2" # Also, make can be passed flags so it run parallel threads e.g.: # PARALLEL_MAKE = "-j 2"
The build environment needs to be setup by the following command:
cd ../.. source poky-init-build-env
A target can be built using:
bitbake <target>
there is a lot of targets, which can be an image (take a look at the "meta/packages/images/" directory) or more simply a recipe corresponding to a software. A detailed list of images can be found on the Poky Handbook. To build an image without X11 server:
bitbake poky-image-base
This step is very long (several hours) and take a lot of space (like 16 gigas) on the host's hard disk. If you are behind a proxy, take a look at this part of Poky's FAQ.
If everything compiles well, the resulting image (rootfs and kernel) will be placed in the directory:
tmp-igep0020b/deploy/images/
and .ipk packages in:
tmp-igep0020b/deploy/ipk/
We will see in section Boot on rootfs and kernel how to use it. Yet, bitbake will download by default the kernel "linux-omap-2.6.28.10-igep0020b-0" which is not the last one provided by ISEE. See section Kernel compilation to compile another version.
TODO: modify recipes to download another kernel version
Cross toolchain for the ARM
Aparently, there is a bug in one of Poky's recipes, which implies that the cross toolchain doesn't include automatically the C++ headers, see this thread. A patch has been proposed; to apply it :
cd $HOME/igep/poky wget http://lists.o-hand.com/poky/att-1420/fix-gxx-include-dir.patch patch -p1 < fix-gxx-include-dir.patch
The cross toolchain can be built using bitbake:
source poky-init-build-env bitbake meta-toolchain-sdk
The result will be placed in the directory:
tmp-igep0020b/deploy/sdk/
as an archive to decompress in the directory "/usr/local/poky".
In order to cross compile code for the ARM, the following script needs to be run to set up paths:
source /usr/local/poky/eabi-glibc/environment-setup-arm-poky-linux-gnueabi
Kernel compilation
Currently, the last stable kernel provided by ISEE is "linux-omap-2.6.28.10-igep0020b-2". Check in the download section of www.myigep.com which is the last one. More recent versions (but unstable) can be downloaded on the git of ISEE.
Kernel compilation under bitbake
Kernel compilation outside bitbake
First, download the kernel sources:
cd $HOME/igep wget http://downloads.myigep.com/sources/kernel/linux-omap-2.6.28.10-igep0020b-2.tar.gz tar -xzf linux-omap-2.6.28.10-igep0020b-2.tar.gz cd linux-omap-2.6.28.10-igep0020b-2
Configure the kernel:
source /usr/local/poky/eabi-glibc/environment-setup-arm-poky-linux-gnueabi make ARCH=arm CROSS_COMPILE=arm-poky-linux-gnueabi- igep0020b_defconfig make ARCH=arm CROSS_COMPILE=arm-poky-linux-gnueabi- menuconfig
The last line is only needed if you want to customize the kernel.
To compile kernel and modules:
make ARCH=arm CROSS_COMPILE=arm-poky-linux-gnueabi- uImage modules
The resulting image is placed in "arch/arm/boot" directory.
We will see in the section Boot on the rootfs and the kernel how to use kernel and modules.
Boot on the rootfs and the kernel
There are several methods to do it. For developing purposes, the easiest way is to boot over network, which avoid flashing operations or coping on the memory card. Yet, these two solutions are essentials for applications where the board need to be independent from the host computer.
Over network
Two servers are needed. The NFS (Network File System) server allows the target to accede its rootfs by the network. The TFTP (Trivial File Transfer Protocol) server allows the target to download the kernel over network. Thus, UBoot needs to be correctly setup to boot on the correct files. To do this, plug a serial cable on the board (115200n8) and stop UBoot by pressing a key. The environment variable of UBoot we need to change are:
- serverip: the server's IP address, need to be on the 192.168.254.x subred (except if you change the board address, which is not explained here). By default, the server's IP address is 192.168.254.10.
- distro: the distribution's name, by default poky.
- machine: the card's name, by default igep0020b.
- project: the project's name, that is to say the rootfs generated previously.
To change a variable, use the command setenv. Thus, to change the project's name and use the one we have just made, set:
setenv project poky-image-base
Then, to boot:
run bootcmd
which will execute the contents of the bootcmd variable. The 'printenv command allow to show the content of a variable; for example:
printenv bootcmd
returns by default:
run mmc-boot; run nfs-boot; run onenand-boot
That is to say the board will first check if a memory card is present to boot with it. If memory card is not present, the board will newt ping the server to boot over network. If server does not answer, the board will boot on the flash. Take a look at mmc-boot, nfs-boot and onenand-boot variables for more details. In addition, the factory settings of UBoot are given here.
In order to save UBoot environment variables in the flash, do:
saveenv
which will avoid to reenter it every time...
Once <serverip>, <distro>, <project>, and <machine> variables setup, UBoot will search on the server of address <serverip>:
- a kernel image uImage in the directory "/srv/tftp/<distro>/<project>/<machine>" accessible by TFTP.
- a rootfs in the directory "/srv/nfs/<distro>/<project>/<machine>" accessible by NFS.
We assume now that <distro>=poky, <project>=poky-image-base and <machine>=igep0020b.
Thus, create the following directories on the host:
sudo mkdir -p /srv/nfs/poky/poky-image-base/igep0020b sudo mkdir -p /srv/tftp/poky/poky-image-base/igep0020b
Next, copy the kernel. If it was made outside bitbake:
sudo cp $HOME/igep/linux-omap-2.6.28.10-igep0020b-2/arch/arm/boot/uImage /srv/tftp/poky/poky-image-base/igep0020b/
or if it was made with the rootfs or with bitbake:
sudo cp $HOME/igep/poky/build/tmp-igep0020b/deploy/images/uImage /srv/tftp/poky/poky-image-base/igep0020b/
Next, install the rootfs in the good directory:
pushd /srv/nfs/poky/poky-image-base/igep0020b sudo cpio -idm< $HOME/igep/poky/build/tmp-igep0020b/deploy/images/poky-image-base-igep0020b.cpio popd
If kernel was built outside bitbake, install kernel modules in the rootfs as follows:
cd $HOME/igep/linux-omap-2.6.28.10-igep0020b-2 source /usr/local/poky/eabi-glibc/environment-setup-arm-poky-linux-gnueabi make ARCH=arm CROSS_COMPILE=arm-poky-linux-gnueabi- modules_install INSTALL_MOD_PATH=/srv/nfs/poky/poky-image-base/igep0020b
Finally, install the two servers on host:
sudo apt-get install tftpd nfs-kernel-server
By default, the TFTP server shares the "/srv/tftp" directory, which is the one we are using. If necessary, you can change this by editing the "/etc/inetd.conf" file :
#:BOOT: TFTP service is provided primarily for booting. Most sites # run this only on machines acting as "boot servers." tftp dgram udp wait nobody /usr/sbin/tcpd /usr/sbin/in.tftpd /srv/tftp
The configuration file of NFS server is "/etc/exports". Add the following line for each rootfs :
# Poky image rootfs /srv/nfs/<distro>/<project>/<machine> <target_ip>(rw,no_root_squash,no_subtree_check,sync)
where <target_ip> is the ip address of the target. By default, igep address is 192.168.254.254. It is also possible to put * to allow a wider range of addresses. In our case, write :
/srv/nfs/poky/poky-image-base/igep0020b 192.168.254.254(rw,no_root_squash,no_subtree_check,sync)
Copy kernel and rootfs in flash memory
Copy can be done either from uboot or linux.
First step is to create the jffs2 file (if you do not have it), which will be used to copy the rootfs. The following package needs to be installed:
sudo apt-get install mtd-utils
Then use the command:
mkfs.jffs2 -r <root file system> -e <erase block size> -o <output file>
where <root file system> is the path to the directory to copy (ie /srv/nfs/poky/poky-image-base/igep0020b), <erase block size> is the block size to erase in KB and <output file> name of the output file. Block size can be seen with the following command:
cat /proc/mtd
On igep, it returns:
dev: size erasesize name mtd0: 00080000 00040000 "X-Loader" mtd1: 00180000 00040000 "U-Boot" mtd2: 00080000 00040000 "U-Boot Env" mtd3: 00300000 00040000 "Kernel" mtd4: 1fa80000 00040000 "File System"
Thus, the size is 0x40000=265KB.
Copy from uboot
Copy from linux
To do this, you will have to boot the card from nfs or memory card; but not from flash.
Partitions can be seen with the following command:
cat /proc/mtd
On igep, it returns:
dev: size erasesize name mtd0: 00080000 00040000 "X-Loader" mtd1: 00180000 00040000 "U-Boot" mtd2: 00080000 00040000 "U-Boot Env" mtd3: 00300000 00040000 "Kernel" mtd4: 1fa80000 00040000 "File System"
To copy the kernel, erase the corresponding memory area before doing the copy:
flash_eraseall /dev/mtd3 nandwrite -p /dev/mtd3 uImage
same thing for the rootfs
flash_eraseall /dev/mtd4 nandwrite -p /dev/mtd4 rootfs.jffs2
And now reboot. In case of errors (such as bad crc on the kernel for example), it is necessary to reflash all, see this.
