RSB+RTEMS 5/6 with QEMU-SMP (ARM realview_pbx_a9_qemu as example)

Since I got a request regarding this blog written in 2016, summarizing again the complete flow with the latest version of RTEMS could be a good idea.

Prepare a suitable workspace according to the adopted operating system on your host (https://docs.rtems.org/branches/master/user/hosts/index.html): 

sudo apt-get build-dep build-essential gcc-defaults g++ gdb git unzip pax bison flex texinfo unzip python3-dev libpython-dev libncurses5-dev zlib1g-dev

Checkout RSB and build:

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

change directory to rsb/rtems/ and type

../source-builder/sb-set-builder --prefix=<the path you like to store the built toolchains> <the name of bsp>

For example, to use QEMU, I need toolchains for ARM, so:

../source-builder/sb-set-builder --prefix=/home/kh.chen/respository/build/. 6/rtems-arm

This will take a while. Please ensure your connection is reliable.

Add the built folder into your PATH. For example, you can add one line in ~/.bashrc:

export PATH=$PATH:~/repository/build/bin
source ~/.bashrc

Now you can checkout RTEMS source tree:

git clone git://git.rtems.org/rtems.git

go to rtems folder:

./bootstrap

Up to here, now RTEMS source tree is ready to build an executable. Here I only demonstrate the configuration for qemu with SMP.

Create a folder to store your built files. For example:

mkdir rtems-build

Please don't do this at the same place of source tree. It may potentially corrupts RTEMS source tree.

Then you can configure the building process as follows (you can remove --enable-debug in case you don't need to use gdb):  

../rtems/configure --target=arm-rtems6 --enable-rtemsbsp=realview_pbx_a9_qemu --enable-smp --enable-tests=yes --enable-debug --prefix=$HOME/repository/rtems-build/

make install -j 4

Now you should be able to run the qemu with the executable (for example generated in testsuite/smptests/.):
qemu-system-arm -no-reboot -nographic -M realview-pbx-a9 -m 256M -kernel <executable> -smp 4

If you are going to use gdb to debug, maybe refer to here 
https://wiki.osdev.org/Kernel_Debugging or https://rtemswithrichi.wordpress.com/debug-with-gdb-and-qemu-on-arm-realview/

My personal experience is as follows:

At first, run up qemu:
qemu-system-arm -net none -nographic -M realview-pbx-a9 -m 256M -kernel  <executable> -smp 4 -no-reboot -s -S
Read symbols from the executable:
arm-rtems6-gdb  <executable> 
Then load the symbols
Now you can set breakpoint at the place you like based on the name of function or the line of the source code.
use continue to run the executable till your breakpoints. 
You can check the registers anytime you want:
info registers