W I S C H N E R

In this -third- part of our tutorial we are going to compile the GNU Debugger. It was ported to the Zilog Z80 architecture by Leonardo Etcheverry and is available from his git repository. The code is old and you need to apply some hacks for it to compile.

First install some additional tools. These are not part of the standard Ubuntu installation:

sudo apt-get install ncurses-dev flex bison

GNU Debugger also requires the texinfo package. But shall avoid compiling documentation because it is outdated and recent versions of texinfo are too strict for the job.

Now fetch gdb-z80 source code by first cd-ing to your ~/dev folder and executing:

git clone https://github.com/legumbre/gdb-z80.git 
cd gdb-z80

You are now ready to compile. Configure the package for cross debugging. Here is the command to do it:

./configure --enable-werror=no --target=z80-unknown-coff

The target of cross compilation is z80. The --enable-werror=no switch turns off error on warning behaviour on newer versions of gcc. The code is too old to pass without warnings and we don't want them to break the compilation.

Before running make we need means to avoid compiling documentation. The tool that we strive to avoid is makeinfo which is part of texinfo package. As you can remember we did not install it. So we are going to make the make think we have it by redirecting it to another tool which will do ... absolutely nothing ... and return success. It just so happens that unix has such a tool. It's called Wine. No, wait. It is called /usr/bin/true.

So here is how we call our make file

make MAKEINFO=true

We apply the same trick to install gdb-z80 to destination folder

sudo make MAKEINFO=true install

If everything went according to our grand plan there are two new files in your /usr/local/bin folder.

ls /usr/local/bin 
z80-unknown-coff-gdb  z80-unknown-coff-gdbtui

Grand! Now install your favourite GDB GUI. I recommend the Data Display debugger. It is absolutely archaic piece of technology and brings you back to the early days of unix when Motif roamed the earth. Just the right tool for ZX Spectrum development.

Install the DDD

sudo apt-get install ddd

And test our system by passing gdb-z80 to the Data Display Debugger using the --debugger option.

ddd --debugger z80-unknown-coff-gdb &

Yaay. You have a debugger for Z80 on your system. Next time we are going to dwelve into remote debugging and step through a program on your ZX Spectrum emulator.

Till then ... be patient.