[Tinyos-devel] Best way to extend tos-bsl

[R. Steve McKown]

Hi,

Our msp430-based sensor node design uses a much different mechanism to 
implement BSL/reset functionality than is currently supported by tos-bsl for 
other platforms.  I'm not terribly experienced with Python, and hope this is 
the right place to discuss the proper way to extend tos-bsl to add support 
for our design.

Our nodes use the cp2103 USB/serial chip, and we've connected two of its 
host-controllable GPIO pins to the uC's RST and TCK/TEST pins.  A standalone 
test program on a Linux host can both sucessfully reset a USB connected node 
and/or cause it to enter BSL mode.  It works well; the cp2103 gpio have no 
power sequencing issues are are glitch-free on USB connect/disconnect.

SiLabs' Windows DLL provides methods to manipulate the state of the GPIO pins, 
and they've provided me enough information to implement similar functionality 
on the Linux platform (Linux host support is a requirement in our project).

Because both the Windows and Linux GPIO methods ultimately require a 'handle' 
to the open USB connection, one option is to add gpio core support in 
specializations of pySerial's serial.Serial class.  That, or pySerial needs 
an externally visible property that can be used to 'link' to helper class 
objects that provide the gpio interaction.

Since I'm new to Python, I'd appreciate any feedback or pointers others on the 
list might be able to provide about how best to add support for our design to 
tos-bsl.  Ultimately, I'd like to contribute a clean enhancement to tos-bsl 
that has a good chance of acceptance into the mainline code.

Thanks for your help,
Steve