Maemo development images with OpenEmbedded


* Introduction 

We have a set of decriptions to support building complete filesystem images 
for the Nokia 770 using the OpenEmbedded build system. The idea of this
project is to have a flexible support for creating various specialized 
filesystems and packages for the Nokia 770 Internet Tablet.


* OpenEmbedded for Maemo and Nokia 770

So what can OpenEmbedded do for a developer who wants to develop software for
Maemo and/or the Nokia 770?
OpenEmbedded now includes support for the Nokia 770 hardware platform. This 
means that you can create filesystem images for this hardware platform 
featuring various pieces of software. The quality of these images depends 
on the hardware support for the Nokia 770 platform of the selected software
package. Apart from Maemo images you can build build images with the GPE 
software environment which has basic support for the 770 (target: gpe-image). 
The Maemo image is intended to become a full-featured development image for
the Nokia 770 Maemo environment. In theory you can build this image for other
hardware platforms, but currently the 770 is the only supported one.


* Environment Setup and Build

Depending on what you intend to do there are several ways to set up OpenEmbedded.
First install the necessary software to run OpenEmbedded, information about this
are located here:
http://oe.handhelds.org/cgi-bin/moin.cgi/RequiredSoftware

It is a good idea to choose a fast computer with at least 512MB of RAM and 5GB 
of free disk space for this task. Both x86 and PowerPC based machines are known
to work.

The basic steps to set up your OpenEmbedded environment are documented here: 
http://oe.handhelds.org/cgi-bin/moin.cgi/GettingStarted
Not that OpenEmbedded changed from Bitkeeper to Monotone for keeping its source, so all the Bitkeeper related information in that page are outdated. For imformation about how to get OE from the revision control system please refer to this page:
http://oe.handhelds.org/cgi-bin/moin.cgi/MonotonePhraseBook

We need one change in the an OpenEmbedded description which isn't in OE for compatibility reasons at the moment. We need to make /sbin/init to become a file instead of a link, otherwise the root filesystem check in the inird will fail. The patch can be found here:
http://download.kernelconcepts.de/sysvinit_2.86.bb_770.patch
Go to the packages/sysvinit subdirectory and apply the patch with the following command:
patch -p0 < sysvinit_2.86.bb_770.patch

[TBD: basic setup in local.conf, file structure]

Depending on which filesystem image you intend to build you need the following setup in your local.conf:

maemo-image: 
	DISTRO = "maemo-1.0"
	MACHINE = "nokia770"

gpe-image:
	DISTRO = "familiar" (or current familiar release like "familiar-0.8.3")
	MACHINE = "nokia770"

After you have set up everything change to your working directory ($TMPDIR) and build your image target running "bitbake maemo-image" or " bitbake "gpe-image".

When the build has finished the image file is located in the subdirectory deploy/images/.

[Add: example files]


* Installation and Test

To install your OE-generated filesystem you need the 770 "flasher" utility and the USB cable which is shipped with the device. You need to have root privileges to run the flasher utility. We assume you have it installed in a directory in PATH.
To flash the filesystem to the device connect the USB cable and run:

flasher -f -r <imagefile>

For details refer to the documentaion of the flasher utility.

The first startup of the image takes some time, so be patient.

Current issues:
- The maemo images are missing locale files and a part of the theme.
- Automatic screen calibration doesn't work in maemo images.
- GPE lacks a proper mapping of the hardware buttons to actions.
- Locale support in GPE images doesn't work.

* Some Internals