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ARM dev tools for Debian (Sid)
=====================================

  :Author: Andrea Manni
  :Copyright: GFDL
  :Version: 0.1

This are just personals notes, it's not meant to be a proper tutorial for public review.

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Debian arch
===============

Modify sources.list to have::
    deb http://ftp.debian.org/debian/ sid main non-free contrib


As often mirrors don't have Debian armhf port available. You need to pull the ftp archive.


Add the right architecture: for ARM we use::

    dpkg --add-architecture armhf
    apt-get update
    dpkg --print-architecture # That's what your host is using
    dpkg --print-foreign-architectures  # That's your target enviroments


Now install the cross compiler, Sid should have a pretty well updated version. You may wanna take a snapshot / backup of the system now::

    lvcreate -s -L5g -n sid_bak /dev/main/sid 
    apt-get install crossbuild-essential-armhf


.. warning::
    The cross compiler is meant to build code for a Linux system, something like a embedded RaspberryPy running Debian and **not a Cortex** ARM processor for any microcontroller.



Test the build chain
=======================

Take whatever C++ example file::

    #include <iostream>                           // a PREPROCESSOR directive
    using namespace std;                      // make definitions visible
    int main()                                    // function header
    {   // start of function body
        cout << "This is ARM code.";  // message
        cout << endl;                             // start a new line
        cout << "You won't regret it!" << endl;   // more output
        return 0;                                 // terminate main()
    }                                             // end of function body



And compile it::
    arm-linux-gnueabihf-g++ hello.cpp
    file a.out

    a.out: ELF 32-bit LSB executable, ARM, EABI5 version 1 (SYSV), dynamically linked, interpreter /lib/ld-linux-armhf.so.3, for GNU/Linux 3.2.0, BuildID[sha1]=0ecbdddcde90341984c81cddc027d9cb127503c9, not stripped



This should work on an OrangePC / RPi::
    
    OrangePI:/tmp:$ dpkg --print-architecture 
    armhf


We can test on x86 (AMD64) using Qemu, after installing you can execute the binary::

    apt-get install qemu-user-static
    apt-get install libicu-dev:armhf # We need some libraries to build something


Libraries should go to: ``/usr/lib/arm-linux-gnueabihf/`` .


Boards
=======

* MSP432 Launchpad is ARM 32Bit Cortex M4F: that's supposed to be ARM **armel** as in: gobjc++-arm-linux-gnueabi
* Nucleo NUCLEO-L476RG has a CPU STM32L476RG: it should be Cortex M4  ARMv7E-M so we compile fo: **armhf**: gobjc-arm-linux-gnueabihf . Ultra-low-power with FPU ARM Cortex-M4 MCU 80 MHz with 1 Mbyte Flash: https://developer.mbed.org/platforms/ST-Nucleo-L476RG/
* OrangePC: armhf , ARMv7 Processor rev 5 (v7l)



Cortex M4 is ARMv7E-M 


Eclipse
========

Download last version of eclipse CDT: https://eclipse.org/cdt/downloads.php


Create a new project "hello world" like::

* Cross compiler Prefix: arm-linux-gnueabihf-
* CC Path:  /usr/bin


It should compile, Project properties -> Tool Chain -> should say ``Cross CC`` .


Debug su remoto embedded
============================

This procedure is for embedded system ala RPi / OrangePi where you have a complete Gnu/Linux OS for running a GDB server. Files can be uploaded with SSH (maybe with a post build hook in Eclipse).

Install from the main archive "General purpose tools" -> Remote System Explorer User Actions" . With this you can have SSH - FTP connection to a remote host in order to upload object files to debug remotely.


GDB server on target
-----------------------------------
::

    apt-get install gdbserver 



Debug client on host - workstation
--------------------------------------
Install the multiarch GDB server and tell Eclipse that it's about ARM::


    apt-get install gdb-multiarch

    vim ~/workspace/arm/.gdbinit
    
    set architecture arm


uC ARM plugin per Eclipse
===========================


Add ``http://gnuarmeclipse.sourceforge.net/updates`` to available repos for Eclipse, install whatever you need according to boards.


- Download STLink-master: https://github.com/texane/stlink.git

::
    cd stlink/ 
    apt-get install autoconf
    ./autogen.sh
    ./configure
    apt-get install libusb-1.0-0-dev 
    make
    sudo make install


STM32 specific
=================

For a Cortex CPU we can't use any g++-5-arm- **linux** -gnueabihf compiler as these are made to copile code to run on an other Gnu/Linux system. We have to install::

    apt-get install  gcc-arm-none-eabi


After a compiler we need a set of libraries to have something working, for an overview of the possibilities check:

- http://www.st.com/st-web-ui/static/active/en/resource/sales_and_marketing/presentation/product_presentation/stm32_embedded_software_offering.pdf

Summary

- Mbed: easiest, most abstract less optimized. Can denvelop from browser. Closed system
- STM32 Cube HAL: abstraction level on hardware, portability, low optimization (but low level APIs available), RTOS
- STM32 Standard peripherali libraries  (SPL): no HAL, less portability, more optimization
- Bare metal, Assembly and C


I have a NUCLEO-L476RG: 1 MB Flash and a fast CPU: we are going to go full abstract with HAL and RTOS. ST provides CubeMX to initialize the uC and provide the libraries / middleware for the code.



MXCube Eclipse plugin
=====================

There's a CubeMX plugin for Eclipse: jar:file:/tmp/stsw-stm32095.zip!/  - http://www.st.com/web/en/catalog/tools/PF257931# . Doc for installing is: http://www.st.com/st-web-ui/static/active/cn/resource/technical/document/user_manual/DM00104712.pdf

Fun Facts: it does not work with Linux 'cause STM are morons.



That can be painfully made to work standalone, it's a matter of exploding the .jar / .zip into something usable as ``java -jar STM32CubeMX.exe``.

Download ``something that goes by the name of stm32cubemx.zip`` from http://www.st.com/web/catalog/tools/FM147/CL1794/SC961/SS1743/PF259242?sc=microxplorer ::

    cd /tmp
    unzip stm32cubemx.zip 
    java -jar SetupSTM32CubeMX-4.12.0.exe 
    cd STM32CubeMX/
    java -jar STM32CubeMX.exe


Yet it does not generate a Eclipse Project, most similar thing is a SW4STM32 .

Links
===================


- http://exploringbeaglebone.com/chapter7/
- https://www.youtube.com/watch?v=T9yFyWsyyGk