Installing Native Toolchain

This page shows you how to install the toolchain to build Mynewt OS applications that run native on Mac OS and Linux. The applications run on Mynewt’s simulated hardware. It also allows you to run the test suites for all packages that do not require HW support.

Note: This is not supported on Windows.

Setting Up the Toolchain for Mac

Installing Brew

If you have not already installed Homebrew from the newt tutorials pages install it (Installing Newt on Mac OS).

Installing gcc/libc

OS X ships with a C compiler called Clang. To build applications for the Mynewt simulator with, a different compiler is used as default: gcc.

$ brew install gcc
...
...
==> Summary
🍺  /usr/local/Cellar/gcc/5.2.0: 1353 files, 248M

Check the gcc version you have installed (either using brew or previously installed). The brew-installed version can be checked using brew list gcc. The default compiler.yml configuration file in Mynewt expects version 5.x for Mac users, so if the installed version is 6.x and you wish to continue with this newer version, modify the <mynewt-src-directory>/repos/apache-mynewt-core/compiler/sim/compiler.yml file to change the default gcc-5 defined there to that displayed by brew list gcc e.g. gcc-6. In other words, replace the lines shown highlighted below:

# OS X.
compiler.path.cc.DARWIN.OVERWRITE: "gcc-5"
compiler.path.as.DARWIN.OVERWRITE: "gcc-5"
compiler.path.objdump.DARWIN.OVERWRITE: "gobjdump"
compiler.path.objsize.DARWIN.OVERWRITE: "objsize"
compiler.path.objcopy.DARWIN.OVERWRITE: "gobjcopy"

with the following:

compiler.path.cc.DARWIN.OVERWRITE: "gcc-6"
compiler.path.as.DARWIN.OVERWRITE: "gcc-6”

In case you wish to use Clang, you can change your <mynewt-src-directory>/repos/apache-mynewt-core/compiler/sim/compiler.yml to use Clang. Delete the gcc-5 DARWIN.OVERWRITE lines highlighted below.

# OS X.
compiler.path.cc.DARWIN.OVERWRITE: "gcc-5"
compiler.path.as.DARWIN.OVERWRITE: "gcc-5"
compiler.path.objdump.DARWIN.OVERWRITE: "gobjdump"
compiler.path.objsize.DARWIN.OVERWRITE: "objsize"
compiler.path.objcopy.DARWIN.OVERWRITE: "gobjcopy"

NOTE: Both the newer gcc 6.x and Clang report a few warnings but they can be ignored.

FURTHER NOTE: Mynewt developers mostly use gcc 5.x for sim builds; so it may take a little while to fix issues reported by the newer compiler. One option is to disable warnings. To do that, remove the -Werror flag as an option for the compiler in the <mynewt-src-directory>/repos/apache-mynewt-core/compiler/sim/compiler.yml file as shown below.

compiler.flags.base: >
    -m32 -Wall -ggdb

You may alternatively choose to specify the precise warnings to ignore depending on the error thrown by the compiler. For example, if you see a [-Werror=misleading-indentation] error while building the sim image, add -Wno-misleading-indentation] as a compiler flag in the same line from the <mynewt-src-directory>/repos/apache-mynewt-core/compiler/sim/compiler.yml file.

compiler.flags.base: >
    -m32 -Wall -Werror -ggdb -Wno-misleading-indentation

A third option is to simply downgrade to gcc 5.x.

Installing gdb

$ brew install gdb
...
...
==> Summary
🍺  /usr/local/Cellar/gdb/7.10.1: XXX files,YYM

NOTE: When running a program with gdb, you may need to sign your gdb executable. This page shows a recipe for gdb signing. Alternately you can skip this step and continue without the ability to debug your mynewt application on your PC.*

Setting Up the Toolchain for Linux

The below procedure can be used to set up a Debian-based Linux system (e.g., Ubuntu). If you are running a different Linux distribution, you will need to substitute invocations of apt-get in the below steps with the package manager that your distro uses.

Install gcc/libc that will produce 32-bit executables:

$ sudo apt-get install gcc-multilib libc6-i386

Install gdb

$ sudo apt-get install gdb

Reading package lists... Done
Building dependency tree
Reading state information... Done
Suggested packages:
  gdb-doc gdbserver
The following NEW packages will be installed:
  gdb
...
Processing triggers for man-db (2.6.7.1-1ubuntu1) ...
Setting up gdb (7.7.1-0ubuntu5~14.04.2) ...