Hi Thomas,
I don't have access to GO920, but in general AFAIK people have had
little luck with opentom.
If you just want to have a custom kernel, a better way is to build
TomTom's own toolchain and compile their kernel. I have done that
myself a few times in the past, with various versions, and I know at
least half a dozen if not more people on the list have done that.
Unfortunately, AFAIK, nobody has bothered to write that down to the
Wiki pages yet. (Writing them down is on my AP list, but below some
200 more urgent things I need to do. I may have some version of the
instructions somewhere in my mail archive -- please let me know if you
are interested.)
Anyway, the source can be downloaded from
http://www.tomtom.com/page.php?Page=gpl
If you know how to build toolchains for embedded Linux, the kernel,
and busybox, the method is relatively straightforward up to the point
where you have the new root file system somewhere on your development
Linux box and the kernel. Then you need to have the tools for
building ttsystem from the Wiki pages. For the root file system,
I've usually unpacked one from the official TomTom distributions and
used that as a base for my own. (Actually I use Mac OS X as my
development platform, and that works well too, with some additional
quirks to get the cross compilation to work.)
--Pekka Nikander
On 22 Aug 2008, at 15:18, Thomas Petazzoni wrote:
Hi,
I've got a « Tomtom GO920(4M00.900) » device, on which I would like to
play with OpenTom. This device has an internal non-removable 4 GB
memory and a slot for one SD card. The internal non-removable memory
contains the system and data for the Tomtom navigation system.
It seems that most tutorials on OpenTom's wiki have been written with
SD card-only Tomtoms in mind: these SD cards can be read/written with
another computer to restore the original system if something went
wrong.
However, with the internal memory, how can this be done ? The internal
memory can be accessed as a regular usb-storage device when the Tomtom
is plugged on its USB dock.
If I change the ttsystem file and the new one doesn't work, the system
won't boot anymore and I won't be able to restore the original
ttsystem, is that correct ? Or is the usb-storage mode of the Tomtom
implemented without using the 'ttsystem' kernel, for example in the
NOR
flash ? Or, alternatively, if a 'ttsystem' file is put on the external
SD card, will the bootloader take it in priority ?
Other questions :
- other Tomtom models appear to have some kind of special connector
through which the serial console can be grabbed. The Tomtom 920 only
has an USB connector, nothing else. So I suppose there is no way of
getting the serial console, is that correct ?
- the device has a «reset» button, but its behaviour is unclear. Does
it simply do an hard reboot, or does it restore something special ?
Thanks,
Thomas
--
Thomas Petazzoni, Free Electrons
Kernel, drivers and embedded Linux development,
consulting, training and support.
http://free-electrons.com
