Introduction

PolyMCU has been designed from the beginning to be as flexible as possible: host OS independent (support Linux, Windows, MacOS), support any toolchain (GCC, LLVM), any RTOS (ARM RTX, FreeRTOS), any micro-controller vendor SDK (Nordic Semiconductor, NXP, Freescale, ST).
Enabling such flexibility provides by the same time better software quality by testing the same piece of software in various configurations. It supports C and C++ languages.

The framework is based on CMake. It provides some examples to build baremetal and RTOS-based projects. In opposition to ARM mBed that provides its own library, PolyMCU used Newlib. No new interface layout has been introduced in the framework. The abstraction layout for ARM architecture is driven by ARM CMSIS v3.0.

Quick start

• For AppNearMe's MicroNFCBoard: here
• To port a new vendor SDK to PolyMCU: here
• Build & Install CMSIS RTOS Conformance test: here

Support

• CMake - version 2.8

• Toolchains:

  • GCC: 4.9-2014: https://launchpad.net/gcc-arm-embedded/4.9/4.9-2014-q4-major
  • Clang: 3.6.0-2ubuntu1~trusty1 (tags/RELEASE_360/final) (based on LLVM 3.6.0)

• RTOS:

  • ARM RTX: V4.79
  • FreeRTOS V8.2.3
  • RioT-OS 2015.09

• Boards:

  • AppNearMe MicroNFCBoard
  • Freescale Freedom KL25
  • Nordic nRF52 Preview DK
  • NXP LP1768 mbed
  • ST STM32L476 Nucleo

• Features:

  • The application defined by APPLICATION can live out of the PolyMCU tree if APPLICATION defined an absolute path.

Status

The latest test results are available at http://labapart.com/products/polymcu/test_results.

Toolchain / Host

Application

Building on Linux

The cross compilation toolchain is either in your PATH or defined by the environment variable CROSS_COMPILE. The latest cross-compilation toolchain for ARM Cortex-M can be found at https://launchpad.net/gcc-arm-embedded.

It is recommended to build out of tree. To do that, create a new directory:

mkdir Build && cd Build

• Case when the application can support multiple board:

cmake -DAPPLICATION=<application_vendor/application_name> -DBOARD=<board_vendor/board_name> ../ && make

• Case when the application targets only a specific board:

cmake -DAPPLICATION=<application_vendor/application_name> ../ && make

• To build a release build:

cmake -DAPPLICATION=<application_vendor/application_name> -DCMAKE_BUILD_TYPE=Release ../ && make

• To make the build verbose:

cmake -DAPPLICATION=<application_vendor/application_name> ../ && make VERBOSE=1

• To build with Clang:

CC=<path-to-clang> cmake -DAPPLICATION=<application_vendor/application_name> ../ && make

Building on Windows

Requirements

• Install CMake: https://cmake.org/download/
• Install the latest GCC v4.9 2015q3 for ARM Cortex M: https://launchpad.net/gcc-arm-embedded/4.9/4.9-2015-q3-update/+download/gcc-arm-none-eabi-4_9-2015q3-20150921-win32.zip
• Install MinGW: http://sourceforge.net/projects/mingw/files/Installer/mingw-get-setup.exe/download (mingw32-base, mingw32-gcc-g++)

Build

1. Download the latest sources of PolyMCU at https://github.com/labapart/polymcu/archive/master.zip

2. Un-archive master.zip

3. Start a command line shell (ie: cmd.exe)

4. Add CMake and MinGW to your PATH if it is not already done. For instance:

SET PATH="c:\Program Files (x86)\CMake\bin";%PATH%
SET PATH=C:\MinGW\bin;%PATH%

5. Add your toolchain into the CROSS_COMPILE. For instance:

SET CROSS_COMPILE=c:\Users\Olivier\gcc-arm-none-eabi-4_9-2015q3-20150921-win32\bin\arm-none-eabi-

6. Create the Build directory into PolyMCU root

cd <PolyMCU Root>
mkdir Build
cd Build

7. [Optional] To build with LLVM

set PATH="C:\Program Files (x86)\LLVM\bin";%PATH%
set CC=clang.exe

8. Build the project

cmake -G "MinGW Makefiles" -DAPPLICATION=<application_vendor/application_name> -DBOARD=<board_vendor/board_name> ..
mingw32-make

• To make the build verbose: mingw32-make VERBOSE=1

Support

All CMake variables that do not start with CMAKE_ and _ are defined in ${CMAKE_BINARY_DIR}/polymcu_config.h which is generated at build time.
This include file can be included in your project to access CMake configuration variables.

Basic variables

Device variables

USB Specific Variables

RTOS variables

Device Specific variables

Debug

Run an application from RAM

To build the firmware to run from RAM:

cmake -DAPPLICATION=<application_vendor/application_name> -DSUPPORT_RUN_FROM_RAM=1 .. && make

Debug with GDB

1. Start the debugger server

pyocd-gdbserver

2. Start the GDB client

arm-none-eabi-gdb <filepath_of_the_ELF_application>
target remote localhost:3333
continue

• Examples of some GDB commands:

(gdb) print $pc
$1 = (void (*)()) 0x200000d8
(gdb) print $sp
$2 = (void *) 0x1fffff58
(gdb) print/x *0x400
$3 = 0x21004692
(gdb) set {int}0x20000000 = 1

(gdb) set arm force-mode thumb
(gdb) display /10i 0x0
1: x/10i 0x0
   0x0 <__Vectors>:	strh	r0, [r0, #0]
   0x2 <__Vectors+2>:	movs	r0, #0
   0x4 <__Vectors+4>:	lsls	r1, r1, #24
   0x6 <__Vectors+6>:	movs	r0, r0
   0x8 <__Vectors+8>:	lsls	r1, r7, #24
   0xa <__Vectors+10>:	movs	r0, r0
   0xc <__Vectors+12>:	adds	r0, #37	; 0x25
   0xe <__Vectors+14>:	movs	r0, r0
   0x10 <__Vectors+16>:	movs	r0, r0
   0x12 <__Vectors+18>:	movs	r0, r0
(gdb) display /10i $pc
2: x/10i $pc
=> 0x1a96 <ARM_USART_Send+18>:	ldr	r3, [sp, #16]
   0x1a98 <ARM_USART_Send+20>:	ldrb	r3, [r3, #0]
   0x1a9a <ARM_USART_Send+22>:	mov	r0, r3
   0x1a9c <ARM_USART_Send+24>:	bl	0x2da8 <app_uart_put>
   0x1aa0 <ARM_USART_Send+28>:	str	r0, [sp, #12]
   0x1aa2 <ARM_USART_Send+30>:	ldr	r3, [sp, #12]
   0x1aa4 <ARM_USART_Send+32>:	cmp	r3, #0
   0x1aa6 <ARM_USART_Send+34>:	bne.n	0x1a96 <ARM_USART_Send+18>
   0x1aa8 <ARM_USART_Send+36>:	ldr	r3, [sp, #16]
   0x1aaa <ARM_USART_Send+38>:	adds	r3, #1

• Dump memory into a file:

(gdb) dump binary memory /tmp/gdb.bin 0x0 0x1000

Debug UART Settings

All the board UARTs are set with the following settings:

• Baud Rate: 115200
• Data Bits: 8
• Stop Bits: 1
• Parity: None
• Flow Control: None