PDA Freedom with OpenZaurus

Despite Sharp's cancellation of its Zaurus SL-6000 PDA in the US,
the Sharp Zaurus continues to have a strong following among Linux gurus
in the US and all over the world. No one proves this point better
than the people behind the OpenZaurus project. The OpenZaurus Project
provides an alternative to the original Sharp Zaurus ROM for different
models of the Sharp Zaurus Personal Mobile Tool.
OpenZaurus vs Sharp ROM
One might think, why would I want to replace my current Sharp Linux
distribution? Although I must admit Sharp's embedded Linux distribution is
pretty impressive, some points could be improved. Some of
these points include SD card compatability and missing utilities,
such as SSH. In addition, OpenZaurus provides 16MB of built-in Flash
separate from the 64MB of memory split between, in the SL-5500, 32MB for
storage and 32MB for heap. The heap memory also can be written to, allowing you to
add and remove applications that you can't touch in the Sharp ROM, such
as the Hancom applications. Most importantly, OpenZaurus offers freedom of choice.

The only visible and most obvious con against OpenZaurus is its lack of
a default Web browser. Although this lack might be a big setback for most
people who enjoy surfing the Web on their Zaurus, it can be remedied quickly
by using an embedded version of the Konqueror Web browser. If you were
in love with the Opera browser on your Sharp ROM, though, tools are available
on-line that can rip Opera from the Sharp ROM and pack it into a nifty
installation package. Both of these applications can be downloaded from the
Zaurus Software Index Web site (see Resources).
Downloading and Installing OpenZaurus
The latest version of OpenZaurus is 3.5.1, and it is a complete change from
all prior versions. For one, the new distribution is built entirely
from scratch using the Open Embedded build system. The new distribution
supports all Sharp Zaurus models except the SL-A300 and SL-6000.
Support for these models is planned for the near future; according
to the Web site, such support will appear in version 3.5.2.

To install OpenZaurus or even the Sharp ROM, you need a
Compact Flash memory card--SD cards will not do! The filesystem on the
Compact Flash card requires one partition covering the entire disk
and a fat16 filesystem. Most Compact Flash cards come formatted with a
fat16 filesystem, but if you need to format your card, enter the following
command--assuming your card is defined by /dev/sda:

$>mkfs.vfat -F 16 /dev/sda1

Next, download the appropriate zImage file from the OpenZaurus Web site
for your particular Sharp Zaurus and its memory constraints. The zImage
file contains the Linux kernel used in OpenZaurus. Also, download the
initrd file, which contains the basic filesystem structure and default programs
for OpenZaurus. For version 3.4.1, three types of initrd files exist and are listed below:

• bootstrap-image.jffs2: contains a minimal image to boot
  a Linux console.
• gpe-image.jffs2: contains a UI for X and the GTK toolkit.
• opie-image.jffs2: an open-source fork of the Qtopia environment.

Choose either GPE or Opie images for a graphical interface or the
bootstrap-image for a simple console interface. The next step is to move
the zImage and initrd file to the root directory of the Compact Flash card.
Remember to rename the files to zImage and initrd.bin; otherwise, the flashing
installation will fail. Now that we have zImage and initrd.bin on
our Compact Flash, its time to flash our Zaurus.

The process of flashing tends to vary among different Zaurus models. For the most
common model, the SL-5000/5500, flashing is done by performing the following steps,
as outlined by the OpenZaurus Web site:

1. Connect your AC adapter to your Zaurus.
2. Move the switch below the battery compartment to
   REPLACE BATTERY. Open the battery compartment lid. Make sure you
   do not take out the battery.
3. Hold down the C and D keys on the Zaurus keyboard,
   and press the FULL RESET button located on the lower-right side
   of the battery compartment.
4. Both the power and mail lights on the Zaurus should light
   up once you let go. Don't touch anything until the lights turn off.
5. Push the FULL RESET button in the lower-right side of
   the battery compartment, replace the lid and power on.

Conclusion and Screenshots
Assuming all went well, you should have a working version of the
OpenZaurus distribution with either the GPE Palmtop Environment (GPE) or the
Open Palmtop Integrated Environment (Opie). Look around and explore!
Here are a few screenshots you should see, depending on the palmtop
environment you used:
GPE ScreenshotsFigure 1. GPE File ManagerFigure 2. GPE DesktopFigure 3. GPE Julia (Fractal Viewer)Opie ScreenshotsFigure 4. Opie DesktopFigure 5. Opie ConsoleFigure 6. Opie Player
In the end, OpenZaurus allows you to push the envelope on the PDA
platform while at the same time promoting Linux and open-source software
and philosophy. Most importantly, it's a lot of fun.
Resources
OpenZaurus Web Site

Zaurus Software Index

Zaurus User Group (ZUG)

Original Sharp ROM

Author's Web Page

Victor Castro is a software engineer for Xroads
Networks in Southern California. He's also a student
at the University of California, Irvine. He can be
reached through
his Web site.