Add line to make file generated by simuliunk in external mode for raspberry pi

In am trying to run a simulink model on the raspberry pi.

The makefile generated by simulink has the following line in it:

       LINKER_CODEGEN_ARGS   :=  -lm -ldl -lpthread -lrt

I need to add the text -lwiringPi to this line.

       LINKER_CODEGEN_ARGS   :=  -lm -ldl -lpthread -lrt -lwiringPi

Does anyone know how i can add this line in the generated makefile?

Answer 1

[John Whittington]

Did you find a resolution for this? It's driving me mad! It seems to ignore the 'Simulation Target > Custom Code'. It's quite frustrating that the Raspberry Pi Support Package is not more documented. It's operation as the standard block library is limited and could be developed if the build process were more explained.

[John Whittington]

After a day on this using 'grep' to find this line I found it uses the linux remote build templates in 'SupportPackages\R2014b\linux\toolbox\realtime\targets\linux\registry\defgmake_remotebuild.mkt'. Even using a brute force approach and changing this file I couldn't get them to reflect the generated Makefile?! It definitely uses the file as changing the name causes an error on the rtw_hook.

I finally found a solution using the (undocumented) command 'xmakefilesetup'. You can add compiler/linker flags and I was able to include -lwiringPi and compile remotely!!!!

[rr rr]

Can you describe this method with xmakefilesetup clearly?

[John Whittington]

Yes, I've created a blog post: http://wp.me/p2C0Bi-bK

Scroll to the 'Remote Build Makefile Setup' section.

Answer 2

[Murat Belge]

I am assuming you are developing a Simulink block that uses the wiringPi library. If you develop your block as a System object, you can specify shared libraries, sources, headers, etc. in a method called updateBuildInfo(). The System objet must inherit from coder.ExternalDependency. You can then import the System object to Simulink as a block. Here is an example System object that uses wiringPi library for digital write:

classdef DigitalWrite_raspi < matlab.System ... & coder.ExternalDependency ... & matlab.system.mixin.Propagates ... & matlab.system.mixin.CustomIcon % % Set the logical state of a digital output pin. %

    % Copyright 2014 The MathWorks, Inc.
    %#codegen
    %#ok<*EMCA>

    properties (Nontunable)
        Pin = 14
    end

    properties (Constant, Hidden)
        AvailablePin = [4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27];
        OUTPUT = 1;
        INPUT  = 0;
    end

    methods
        % Constructor
        function obj = DigitalWrite_raspi(varargin)
            coder.allowpcode('plain');

            % Support name-value pair arguments when constructing the object.
            setProperties(obj,nargin,varargin{:});
        end

        function set.Pin(obj,value)
            coder.extrinsic('sprintf') % Do not generate code for sprintf
            validateattributes(value,...
                {'numeric'},...
                {'real', 'positive', 'integer','scalar'},...
                '', ...
                'Pin');
            assert(any(value == obj.AvailablePin), ...
                'Invalid value for Pin. Pin must be one of the following: %s', ...
                sprintf('%d ', obj.AvailablePin));
            obj.Pin = value;
        end
    end

    methods (Access=protected)
        function setupImpl(obj)
            if coder.target('Rtw')
                coder.cinclude('digitalio_raspi.h');
                coder.ceval('digitalIOSetup', obj.Pin, obj.OUTPUT);
            end
        end

        function stepImpl(obj,u)
            if coder.target('Rtw')
                coder.ceval('writeDigitalPin', obj.Pin, u);
            end
        end

        function releaseImpl(obj) %#ok<MANU>
        end
    end

    methods (Access=protected)
        %%Define input properties
        function num = getNumInputsImpl(~)
            num = 1;
        end

        function num = getNumOutputsImpl(~)
            num = 0;
        end

        function flag = isInputSizeLockedImpl(~,~)
            flag = true;
        end

        function varargout = isInputFixedSizeImpl(~,~)
            varargout{1} = true;
        end

        function flag = isInputComplexityLockedImpl(~,~)
            flag = true;
        end

        function varargout = isInputComplexImpl(~)
            varargout{1} = false;
        end

        function validateInputsImpl(~, u)
            if isempty(coder.target)
                % Run this always in Simulation
                validateattributes(u,{'logical','double'},{'scalar','binary'},'','u');
            end
        end

        function icon = getIconImpl(~)
            % Define a string as the icon for the System block in Simulink.
            icon = 'Digital Write';
        end
    end

    methods (Static, Access=protected)
        function simMode = getSimulateUsingImpl(~)
            simMode = 'Interpreted execution';
        end

        function isVisible = showSimulateUsingImpl
            isVisible = false;
        end
    end

    methods (Static)
        function name = getDescriptiveName()
            name = 'Digital Write';
        end

        function b = isSupportedContext(context)
            b = context.isCodeGenTarget('rtw');
        end

        function updateBuildInfo(buildInfo, context)
            if context.isCodeGenTarget('rtw')
                % Update buildInfo
                rootDir = fullfile(fileparts(mfilename('fullpath')),'src');
                buildInfo.addIncludePaths(rootDir);
                buildInfo.addIncludeFiles('digitalio_raspi.h');
                buildInfo.addSourceFiles('digitalio_raspi.c',rootDir);
                buildInfo.addLinkFlags({'-lwiringPi'});
            end
        end
    end
end

And here are the associated source files:

digitalio_raspi.c:

#include <wiringPi.h>
#include "digitalio_raspi.h"

// Digital I/O initialization
void digitalIOSetup(uint8_T pin, boolean_T mode)
{
    static int initialized = false;

      // Perform one-time wiringPi initialization
      if (!initialized) {
          wiringPiSetupGpio();
          initialized = 1;
      }

      // mode = 0: Input
      // mode = 1: Output
      if (mode) {
          pinMode(pin, OUTPUT);
      }
      else {
          pinMode(pin, INPUT);
      }
  }

// Read logical state of a digital pin
boolean_T readDigitalPin(uint8_T pin)
{
    return ((boolean_T)digitalRead(pin));
}

// Write a logic value to pin
void writeDigitalPin(uint8_T pin, boolean_T val)
{
    digitalWrite(pin, val);
}
// [EOF]

and digitalio_raspi.h:

#ifndef _DIGITAL_IO_RASPI_H_
#define _DIGITAL_IO_RASPI_H_
#include "rtwtypes.h"

void digitalIOSetup(uint8_T pin, boolean_T mode);
boolean_T readDigitalPin(uint8_T pin);
void writeDigitalPin(uint8_T pin, boolean_T val);

#endif //_DIGITAL_IO_RASPI_H_

Answer 3

[Murat Belge]

If you want to add a:

• Source file
• Header file
• Linker flag

unconditionally in your Simulink model, you can add an InitFcn callback to your model and use one of the following functions in the callback:

realtime.addBuildInfoSrcFile(<source file>, <model name>)
realtime.addBuildInfoIncPath(<include path>, <model name>)
realtime.addBuildInfoLinkerFlag(<linker flag>, <model name>)

For example, to add '-lwiringPi' linker flag use the the following in the model InitFcn callback:

realtime.addBuildInfoLinkerFlag('-lwiringPi',gcs)

To additionally specify the location of the shared library use the following:

realtime.addBuildInfoLinkerFlag('-lwiringPi -L/usr/lib/',gcs)

In all three functions above, you can specify a cell array of source files, include paths or linker flags.

[John Whittington]

Thanks for these replies Murat, they are useful. The 'realtime.addBuildInfo' doesn't seem to be unconditional however. I get the error:

 'Attempt to reference field of non-structure array.'

Using 'xmakefilesetup' as I said in my reply is the only way I can get it working.

[Stephane Camp]

Hi John. Thank you so much for xmakefilesetup. It worked ! after struggling so long, I finally end up with your post. You saved my week.