This directory contains hardware platforms that TinyOS runs on. A hardware
platform is a collection of "chips," such as microcontrollers, radios,
and non-volatile storage, whose implementations can be found in tos/chips.

A platform includes code for the hardware resources that chip functionality 
depend on. For example, the CC1000 chip has a software networking stack (in
chips/cc1000), which depends on being able to send bytes to the CC1000
chip over an SPI bus. How the SPI bus works is platform dependent (e.g.,
it could be shared between several chips and require software arbitration).
Therefore, the mica2 platform, which has a CC1000 radio, connects the
CC1000 code to an SPI bus that its microcontroller, an ATmega128, provides.

Every platform directory has a ".platform" file, which specifies 
flags and options to the nesC compiler. For example, the native compiler
ncc uses to compile a binary depends on what microcontroller a platform
has, so a .platform file generally specifies the compiler with the 
"-gcc" option. Also, as platforms depend on a collection of chips, the
.platform file specifies those chips with "-I" options.

The standard TinyOS boot sequence depends on a platform providing
a few components; details can be found in TEP 107.

Phil Levis, last updated: 7/7/2005

