Mem Proxy
=========

Introduction
------------

Mem Proxy consists of three components:

mem-proxy - a kernel module that allows userland processes
access to the kernel address space.

mem-proxyd - a daemon which allows applications running on
other machines access to the mem-proxy module.

Client library - a high-level library which allows scripts
to access mem-proxyd over the network.


So What is it good for?
-----------------------

I've used this initally to play around with the GPIO pins 
on my Edimax BR-6104KP.  I was writing a 7-segment display 
driver and it was much easier to get the logic right by
writing it in Python and then converting to C, than 
developing directly in C.  Use of Python on a remote 
machine requires no compile->Upload->Flash->Boot cycle
so is far more rapid.  Since playing about with the GPIO
pins I've added kmalloc() and kfree() capability, since
some devices like USB controllers need to write results
to DMA memory.

You could use this to prototype an MMC driver or investigate
IO pins/LEDs on unknown routers.  For some applications it
may be that this can be used to avoid writing a driver
altogether - with embedded applications the kernel->userland
divide sometimes just gets in the way.


Usage instructions
------------------

- I'm Assuming a recent svn checkout of OpenWrt Kamikaze from
  dev.openwrt.org.
- go to the packages directory::

    $ cd trunk/packages

- Get the source::

    $ svn co http://linux-adm5120.svn.sourceforge.net/svnroot/linux-adm5120/trunk/BR-6104K/OpenWrt/mem-proxyd
    $ svn co http://linux-adm5120.svn.sourceforge.net/svnroot/linux-adm5120/trunk/BR-6104K/OpenWrt/mem-proxy

- Now run 'make menuconfig' and select mem-proxy from kernel modules->other,
  and mem-proxyd from utilities.

- Build using::

    $ make V=99

- Burn the firmware or upload it to DRAM.

- The firmware should boot, the mem-proxy module should get loaded
  automatically and the mem-proxyd daemon should get run, although
  this may occur a few seconds after getting the OpenWrt shell.

- The directory trunk/packages/mem-proxyd/examples contains both the client
  library (mem.py) and a couple of examples for the Edimax router, one
  to flash the LEDs on and off, and another to access the USB controller.

- Using the library is pretty easy from Python.  Assuming your router
  has address 10.0.0.44::

    $ python
    >>> import mem
    >>> myrouter = mem.Proxy("10.0.0.44")
    >>> data = myrouter.Read(0xb2000000)

- See the examples for further details.  If you access hardware registers
  you need to map their addresses into KSEG1 - see the examples for details.



If you find this useful, send me an email at: bifferos@yahoo.co.uk.