[ASK] Basic L4Re

Matthias Lange matthias.lange at kernkonzept.com
Mon Oct 13 10:23:27 CEST 2014


On Sat, Oct 11, 2014 at 01:21:11AM +0700, Erry Pradana Darajati wrote:
> Hello L4 Hackers
> I am working on a project with L4Re in Pandaboard for my College Final
> Project. And right now i am in a stuck.
> So far, i have already know how to boot, print and read from the serial
> port (UART3) of pandaboard. But i can't understand the fundamental / basic
> of L4Re itself.

A good starting point is the L4Re documentation [0]. This should get you

> Like how to make a new program outside the main program of "hello" (i am
> using hello code all of this time to experimenting). And also how to access
> the memory of the host computer using L4Re code.

Just create a new directory within you pkg directory. From there you can call
'../../mk/tmpl/inst' which installs the default directory hierarchy and

> Because the main goal of the project i am working on is be able to access
> the GPIO of Pandaboard.

The io server already provides infrastructure and the API for GPIO drivers.
Please have a look at the existing BCM2835 and OMAP3 drivers.

> And also, is there is any way to recompile L4Re without recompiling all of
> the module it use. Because in my computer it took a time to recompile even
> the change is only a line of code

You have multiple possibilities. Change into your pkg's directory and call
'make -jX O=/path/to/obj/dir' or from your build directory you can call 'make
-jX S=YOUR_PKG_NAME'. Note that the latter will not check and rebuild the pkg's


[0] http://os.inf.tu-dresden.de/L4Re/doc/

Matthias Lange, matthias.lange at kernkonzept.com, +49 - 351 - 41 88 86 14

Kernkonzept GmbH.  Sitz: Dresden.  Amtsgericht Dresden, HRB 31129.
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