Bill Cunningham wrote:
What is the purpose of a free standing implementation of C?
stdio.h isn't even included. I've only used hosted
implentation.
Basically, it provides for those environments where C programs
can have non-standard entry/exit mechanisms, i.e. no command line
(and hence no command line parameters, no system() function that
depends on a shell or command line interpreter, and (perhaps)
nothing to return to.
Most of the free-standing implementations are embedded
applications (e.g. cable modem, washing machine); and the
remainder are the "host" part of hosted systems (ex: kernel, I/O
subsystems).
Free-standing implementations are free to dispense with support
for those elements set forth in the standard that just don't make
any sense in their particular context. Typically, the standard
I/O capabilities are severely trimmed or omitted, memory
management may be dropped in favor of pre-allocated
regions/variables, and pointers to specific memory, I/O, and
control space locations may abound.
--
Morris Dovey
West Des Moines, Iowa USA
C links at
http://www.iedu.com/c