laforge at gnumonks.org
Fri Jun 25 01:28:09 UTC 2010
As indicated in other mails, we now have support for gcc-style constructors
in OsmocomBB. The way to use them is relatively easy: Simply put
"__attribute__((constructor))" at the function that you want to be
called during initialization.
The way how this works is like this:
* gcc and the linker create a table of function pointers to all the
functions with that attribute
* the code in compal_ramload_start.S takes care of calling
lib/ctors.s:do_global_ctors() which iterates over the list
and calls each constructor
This concept is now used for things like prim_fbsb_init() in layer1,
but I have also started to use it for board_init(). This means that
board_init() no longer needs to be called from the main() function
of each app.
We can probably put more stuff into constructors, but we should also
be careful as with gcc-4.0.2 we cannot yet indicate priorities and thus
there is no explicit way to control the ordering in case of dependencies.
- Harald Welte <laforge at gnumonks.org> http://laforge.gnumonks.org/
"Privacy in residential applications is a desirable marketing option."
(ETSI EN 300 175-7 Ch. A6)
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