ttsiodras / grlib-gpl

My optimistic - yet unexpectedly successful - attempt to create a LEON3 inside my FPGA boards (ZestSC1, Pano Logic G2)

Running a grlib-gpl Leon3 inside my ZestSC1

This repo contains my (unexpectedly) successful creation of a LEON3 inside my ZestSC1 FPGA board. The work was based on the GPL version of Gaisler's GRLIB, and was performed in one week: from the weekend of March 2nd 2019, and all through the four evenings that followed it (after work).

Finally, in the evening of March 7th I proudly saw my board respond to GRMON3:

I also kept a complete log of the attempt as I was going, here.

So... I "compiled" my own CPU! Another "magic thing" demystified :-)

And since I begun learning the ropes 30 years ago on a SPARCstation running at 40MHz... the emotional high of "compiling my own SPARC" in my FPGA was, well, priceless :-)

Hats off to the Gaisler people; for making things so easy that even a complete newbie (HW-wise) like me, can actually put the pieces together.

UPDATE: Here's the complete log of the execution of the Dhrystone 2.1 benchmark in my Leon3; a benchmark that I barely managed to squeeze in my puny 16KB of BlockRAM :-)

Running a grlib-gpl Leon3 inside my Pano Logic G2

UPDATE, many months later: I got my hands on a Pano Logic G2, thanks to the magnificent Tom Verbeure.

After soldering my, erm, custom JTAG "adapter"...

...I was able to "see" the board from my Arch Linux:

...and two evenings later, I bootstrapped a Leon3 again - but this time, via JTAG (order(s) of magnitude faster than UART), and since the XC6LX100 is a monster (compared to the Spartan3), with 16 times more memory, and 4 Leon3 cores!

In any case, I need to write a blog post about this - I've done too many things, that must be documented.

UPDATE: I finally found the willpower to document everything, in a very detailed blog post. Enjoy!