Gumstix

Instructions for building player into the Gumstix OS for use with iRobot

Get Buildroot

To use the Buildroot, you must first obtain the Buildroot.

All files are available from Gumstix's public Subversion repository.

You will need the following things on your development host machine:

• A Subversion client, to check out the files (and, later, to get updates). You can check if your Linux box already has one by entering which svn at the command prompt.
• A C compiler, such as gcc and associated tools. Most Linux systems already have these tools installed; if yours are missing, install your distribution's development tools package.
• You will need to following tools installed: autoconf, automake, bison, byacc, gcc, gcc-c++, make, ncurses-devel, subversion, zlib-devel, texinfo, flex.
• A network connection, both to fetch the Buildroot itself, and for the Buildroot to download subsequent files.
• About 150MB of free disk space.

To check out the current revision of the Buildroot, enter the following on your development host:

svn co http://svn.gumstix.com/gumstix-buildroot/trunk gumstix-buildroot

Configure And Make Buildroot Toolchain

now type

cd gumstix-buildroot
make defconfig
rm .config
make

This will stop and prompt you for the "Target Architecture Variant". Choose either

• "11. xscale (eg Gumstix basix/connex) (BR2_xscale) (NEW)"
• "12. iwmmxt (eg Gumstix verdex) (BR2_iwmmxt) (NEW)".

Then you will be prompted for the processor speed of your gumstix. Make the appropriate selection.

make menuconfig

• Under "toolchain options" activate "build/install c++ compiler and libstdc++".
• Under "Package Selection for the target" activate "wpa_supplicant", "libtool"
• Under "Package Selection for the target" deactivate "gpsd"

make

Take a break ;) this takes a while.

When you're finished, you can double check to ensure that the xdr routines are present by doing:

cd build_arm_nofpu/staging_dir/lib
../bin/arm-linux-nm libc.a | grep xdr_bytes

and you should see:

U xdr_bytes
00000594 T xdr_bytes

Your toolchain will have a bin directory where the cross-compiling executable tools, such as arm-linux-gcc and arm-linux-ld reside.

This is located at [path to build root]/build_arm_nofpu/staging_dir/bin

Add this directory to your PATH environment variable.

Removing Packages from the Filesystem

If you enter the configuration menu and deselect a package, you may be surprised to discover that it's still in your filesystem image.

The Buildroot will rebuild only the aspects of your system that have changed -- and if you deselect a package, the change is that the Buildroot now no longer even looks at the package. It will not build the package's files, but it will also not remove them.

You can fix this by manually removing the package's files from gumstix-buildroot/build_arm_nofpu/root, or simply by erasing that whole directory -- the Buildroot will restore it when you next run make.

ATTENTION wifistix users- If you delete the gumstix-buildroot/build_arm_nofpu/root directory then the wifistix support will not be properly re-installed unless you also delete the gumstix-buildroot/build_arm/.cf8385 file.

Configure And Build Player

From player base diretory type:

$ ./configure --build=x86-linux --host=arm-linux --disable-shared --disable-alldrivers --enable-roomba --prefix=[path to buildroot]/build_arm_nofpu/root/usr/local

The configure script will automatically look for the arm-linux- tools, which should already be in your PATH.

From player base diretory type:

make

One final step to save space is to strip the symbol/debug information out of the binary:

arm-linux-strip server/player

Now just type:

make install

Finish Configuration

• roomba.cfg

driver
(
  name "roomba"
  provides ["position2d:0" "power:0" "bumper:0" "sonar:0"]
  port "/dev/ttyS0"
  safe 1
)

• switch tty

Login to gumstix and edit /etc/inittab change the following:

::respawn:/sbin/getty -L ttyS0 115200 vt100M

to

::respawn:/sbin/getty -L ttyS2 115200 vt100M

Flash The File System (With A Serial Cable)

You can flash a Gumstix easily using a standard serial cable and Kermit/cKermit, or a communications program that supports Kermit-style file transfer. Connect the cable to the Gumstix's console serial port and start your communications software.

WARNING: TeraTerm on the Windows platform is know to have a broken kermit implementation which will cause corruption in files it transfers. Do not use TeraTerm to transfer files to u-boot for flashing, or you run severe risk of rendering your gumstix un-bootable

To flash the Gumstix, you will be communicating with the uboot bootloader. Uboot uses 115200 baud, 8 data bits, 1 stop bit, and no parity (115200/8n1), with no flow control. For the Kermit-style file transfer, your communications software must be set to send files in binary format.

Now, turn on your Gumstix. Almost immediately, it will prompt you (through the serial console) to press any key to stop booting and access uboot. Press a key and enter the following:

set carrier-watch off
set speed 115200
set file type bin
set reliable fast
set flow-control none
set rec pack 4096
set send pack 4096
set window 5
set prefixing all

At the GUM Uboot prompt, tell it to receive a file:

loadb a2000000

(There are six zeros following the a2 in that line.)

Now, send your filesystem image. Once your file transfer succeeds, the Gumstix is holding your new filesystem in RAM. The contents of Flash are still intact; aborting at this point will simply revert to your old filesystem.

Getting the new filesystem to take hold is a two-step process. First, the old filesystem must be erased; then, the new filesystem must be written from RAM to flash.

To erase the old filesystem, enter

protect on 1:0-1
erase all

The first line protects flash sectors 0 and 1, which contain the uboot bootloader you're currently communicating with. This line is very important. If you omit it, your Gumstix will be unusable and will have to be reflashed using a far more complicated process.

Now, commit your new filesystem to flash:

cp.b a2000000 40000 ${filesize}

This copies your new filesystem into flash (at address 40000 hex, for the curious). ${filesize} is a reference to the variable filesize, which was set by your file transfer. If this does not work simply convert the size of rootfs.arm_nofpu.jffs2 into hex (lowercase letters) and use instead. Also on different versions of uboot the variable can be either ${filesize}, $(filesize) or $filesize.

Once the copy completes, you can boot directly into your new filesystem by typing:

boot

Alter bootloader (uBoot)

Access the uBoot boot loader and type the following:

setenv silent true
setenv bootargs console=ttyS2,115200n8 root=1f01 rootfstype=jffs2 reboot=cold,hard
saveenv