RTEMS

This is my documentation as I am exploring developing for RTEMS. The original documentation can be found in Original Documentation.

All documentation for RTEMS are also available under one link.

Everything done here is done in a Linux machine.

Table of Content

Introduction and Building
Project: Paravirtuatization
Project: Priority Inversion
Habeeb's Project: Moving on to compiling bsp for tm4c129e TI's TM4C arm architecture

Diagram of how rtems is organized

RTEMS Organization

The <root-dir>/rsb directory contains the RSB. The <root-dir>/4.12 directory contains the build set for each architecture we are running RTEMS on.

Theory

RTEMS Source Builder (RSB):

is a tool to aid building packages from source used by the RTEMS project.
Has two types of configuration data
- A build set:
  - A build set describes a collection of packages that define a set of tools you would use when developing software for RTEMS. For example the basic GNU tool set is binutils, gcc, and gdb and is the typical base suite of tools you need for an embedded cross-development type project.
- Configuration Files:
  - They define how a package is built.
  - They are scripts that:
    - Prepare
    - Build
    - Install packages

RSB installs into a build prefix. Prefix:

the top of a group of directories containing all the files needed to develop RTEMS applications.

RSB is a builder for toolchains. Toolchains are required for rtems architecture as shown in the RTEMS Organization diagram above

Configure the development environment

Create a sandbox environment

$ cd
$ mkdir -p development/rtems
$ cd development/rtems

Prerequisite

Download the following packages. Debian packages are mentioned here.

sudo apt update
sudo apt upgrade
sudo apt install bison texinfo flex make binutils gcc g++ gdb unzip git python2.7-dev zlib1g-dev libncurses5-dev

Setting Up With RTEMS Source Builder RSB

Download the source for rsb

$ git clone git://git.rtems.org/rtems-source-builder.git rsb

Check if your computer can support building the toolchain

$ cd rsb
$ ./source-builder/sb-check

Continue only if your output is similar to:

RTEMS Source Builder - Check, 4.12 (4c5eb8969451)
Environment is ok

Build Toolchains

We build toolchains (the required tools/programs to build a runnable RTEMS OS on an computer architecture) for any architecture we want. Here we build the toolchains for sparc, arm, powerpc, and i386 architecture, and also a qemu virtualization so we can work with a virtual machine that has RTEMS OS on top of qemu virtualization.

$ cd $HOME/development/rtems/rsb/rtems
$ ../source-builder/sb-set-builder --prefix=$HOME/development/rtems/4.12 4.12/rtems-sparc
$ ../source-builder/sb-set-builder --prefix=$HOME/development/rtems/4.12 4.12/rtems-arm
../source-builder/sb-set-builder --prefix=$HOME/development/rtems/4.12 4.12/rtems-powerpc
$ ../source-builder/sb-set-builder --prefix=$HOME/development/rtems/4.12 4.12/rtems-i386
$ ../source-builder/sb-set-builder --prefix=$HOME/development/rtems/4.12 --without-rtems devel/qemu

Now, we have the required tools (gcc, gdb, ...) for the architecture mentioned above. Let's get the RTEMS source code so we can build a system with RTEMS running on a specific architecture.

Build RTEMS

Download the RTEMS OS

cd $HOME/development/rtems
mkdir kernel
cd kernel
git clone git://git.rtems.org/rtems.git rtems

Set up the path

export PATH=$HOME/development/rtems/4.12/bin:$PATH #Or add to your PATH variable.

Initialize the default files (.ac and .am to executables) in the rtems source

This step initializes all the default files required. Only run this the first time, or when we add new files. Do not run this when we update any file in RTEMS source.

cd $HOME/development/rtems/kernel/rtems
./bootstrap -c && ./bootstrap -p && $HOME/development/rtems/rsb/source-builder/sb-bootstrap

bootstrap -c is for cleaning all the remaining make and config files bootstrap -p is for doing smt with the preinstalled things and we use the sb-bootstrap from the previously received rsb for building the make and config files from .ac and .am files

Build BSPs

# for erc/sparc
cd $HOME/development/rtems/kernel
# build the sparc/erc32 machine
# create a directory to keep the bsp for sparc/erc32
mkdir erc32
cd erc32
$HOME/development/rtems/kernel/rtems/configure --prefix=$HOME/development/rtems/4.12 --target=sparc-rtems4.12 --enable-rtemsbsp=erc32 --enable-posix
make all
make install

# build for arm/b_realview_arm
cd $HOME/development/rtems/kernel
mkdir b-realview_pbx_a9_qemu
cd b-realview_pbx_a9_qemu
# Compile the realview-pbx-arm machine's kernel files
$HOME/development/rtems/kernel/rtems/configure --target=arm-rtems4.12 --disable-networking --enable-rtemsbsp=realview_pbx_a9_qemu --enable-posix --prefix=$HOME/development/rtems/4.12
make all
make install

# build for i386/pc386
cd $HOME/development/rtems/kernel
mkdir pc386
cd pc386
# compile the pc386 machine's kernel files (build rtems for pc386)
HOME/development/rtems/kernel/rtems/configure --target=i386-rtems4.12 --prefix=$HOME/development/rtems/4.12 --enable-rtemsbsp=pc386 USE_COM1_AS_CONSOLE=1 BSP_PRESS_KEY_FOR_RESET=0

# Notes on the USE_COM1_AS_CONSOLE=1 and BSP_PRESS_KEY_FOR_RESET=0 options can be found in https://devel.rtems.org/wiki/Developer/Simulators/QEMU#Usingthertems-testingModule

# build for powerpc/psim
cd $HOME/development/rtems/kernel
mkdir psim
cd psim
# Compile the psim machine's kernel files
$HOME/development/rtems/kernel/rtems/configure --target=powerpc-rtems4.12 --enable-rtemsbsp=psim --enable-posix --prefix=$HOME/development/rtems/4.12
make all
make install

In english, the command above says (I am guessing here), compile RTEMS for arm-rtems4.12, using the tools from --prefix with the added options of disabling networking.

We need these to confirm that nothing is wrong with the rtmes or toolchain in case we have errors for tm4c129e

Running Programs

Running ticker.exe for sparc

# run from the root directory for the rtems build for sparc
sparc-rtems4.12-run -v `find . -name ticker.exe`

Running ticker.exe for arm

# run from the root directory for the rtems build for arm
QEMU_AUDIO_DRV=none qemu-system-arm -no-reboot -net none -M realview-pbx-a9 -m 256M -serial stdio -kernel `find . -name ticker.exe`

Running ticker.exe for i386

# run from the root directory for the rtems build for i386
qemu-system-i386 -kernel `find . -name ticker.exe` -append "--console=/dev/com1" -serial stdio

Since I was not able to run ticker.exe, I ran rtems-test in rtems-tools. Link to RTEMS tester - ftp://ftp.rtems.org/pub/rtems/people/chrisj/rtems-tester/rtems-tester.html

cd $HOME/development/rtems/rsb/.../rtems-tools/
rtems-test --rtems-bsp=psim-run --rtems-tools=$HOME/development/rtems/4.12 \ /home/rtemsuser/development/rtems/kernel/psim/powerpc-rtems4.12/c/psim/testsuites

Moving on to compiling bsp for tm4c129e

What I have done so far:

Create a new directory and get Habeebs code that claims to have built a bsp for TM4C129E board

cd ~/development/
git clone https://github.com/Dipupo/rtems.git haheeb-rtems

Create the patch files of the commits that habeeb implemented

cd ~/development/habeeb-rtems
git format-patch b30ab25 --stdout > ~/development/rtems/kernel/rtems/habeeb_diff.diff

apply the patch files created

cd ~/development/rtems/kernel/rtems
git apply --reject habeeb_diff.diff

In my case, I got two .rej files. On inspection, I only needed to delete them because they were implemented, probably in another commit as well.

compile the bsp

cd ~/development/rtems/kernel
cd rtems
./bootstrap -c && ./bootstrap -p && $HOME/development/rtems/rsb/source-builder/sb-bootstrap

cd ..
mkdir tm4c129e
cd tm4c129e
$HOME/development/rtems/kernel/rtems/configure --target=arm-rtems4.12 --disable-networking --enable-rtemsbsp=tm4c129e --enable-posix --prefix=$HOME/development/rtems/4.12

make all
make install

Here, make all gives the error as mentioned in Error file

Useful Commands

List all bsps

$ $HOME/development/rtems/kernel/rtems/rtems-bsps

List all architectures

$ $HOME/development/rtems/rsb/source-builder/sb-set-builder --list-bsets

Troubleshooting

Missing Packages or Broken Mirror

If some packages are missing, you may need to download the zip from somewhere. I have some save in google drive since the mirrors seem to be broken. You can download the required packages at Drive

sammanthp007 / RTEMS-Documentation

readme