Tim Woodall ([EMAIL PROTECTED]) wrote: > 3. We already have some magic in the usermode driver - the cell header > CRC calculation. When someone started having some problems I spotted that > the code to calculate the CRC had been removed and a constant (0xcb IIRC) > was being used instead. This looked like a bug to me and I wasted some > time writing some code to calculate and cache the CRC values.
I can answer to this one Tim :-) We put a fixed value because the modem computes them on the fly when i relays atm cells from its USB "mailbox" to the adsl physical link. You have this explained in some specifications of previous "DSL" chipset that was manufacturing Alcatel. >From these specs, we could reverse engineer a bit of the "initialization" code and how to communicate with the modem when the firmware was not active yet. We discovered how the firmware was encapsulated in a format that was directly parsed by the code contained in the modem_run's binary array... Of course we discovered lot of things We could even play with the LEDs (blinking them and so on) but we experienced problems with a kind of watchdog that could not be disabled and was switching off the modem. Well, all that speech is just to show how much our driver is weak if we don't have the specifications. Moreover, our reverse engineering work is clearly illegal in some countries (and we could be sued in the US if thomson claims that we are circumventing their protections and violating their IP). Being illegal, our work cannot be distributed in these countries... We want specs to make sure the driver will work in an understandable way in the future, whoever is the maintainer. Don't forget I'll quit the project sooner or later, so will do Francois and so did Benoit. If tim quits then nobody will be able to understand most of the user space driver because modem_run (the most important piece of software) is only black voodoo sending some unknown vendor commands to another black voodoo software on the modem (firmware). Just my 0.02¤ -- or why paying hardware if companies don't give us the knowledge to use them ? -- Edouard Gomez -- Attached file included as plaintext by Listar -- -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.1 (GNU/Linux) iD8DBQE+TRLtR5dTYz5sWMcRAo3FAJsHoiydgkqZ6TJODgpgeMZCWHvSgACfaCSC MjRK7rGXjd3MZxJwm2v7KL4= =HVv9 -----END PGP SIGNATURE----- Liste de diffusion modem ALCATEL SpeedTouch USB Pour se désinscrire : mailto:[EMAIL PROTECTED]?subject=unsubscribe
