Hey, I wrote an assembler.

(It was about time I interrupted a never ending pile of drafts with something)

So, for a bit more than a month I’ve been attending a seminar on VHDL microcontroller design.

One of the workshops involved doing some simple exercises on eval boards. While the overall instruction set is small (fits on less than a page) the idea of programming and then assembling the sources using pencil and paper wasn’t very appealing at the moment.

It sure is a fun way to keep the mind fresh but given time constraints I couldn’t cope with such a long debugging cycle.

And… The obvious path was to build a tool.

I reused parts of python-lx200 because smart data structures and dumb code are nice. Most of this could be implemented with M4 too, perhaps for another code golf session.

A couple of years ago I’d probably tried to use Bison and Flex but doubt that I could manage something like this in just a handful of hours during the weekend.

There are some rough edges but as it is it supports labels, variable definitions and emits a valid IHEX file. I made a couple of dumb mistakes but they were really evident when looking at what Quartus made of the output file.

I’m quite proud of the result, I don’t know when was the last time I had so much fun doing a one off project, even if it wouldn’t be used anymore after the seminar.

The source code lives here: https://github.com/pardo-bsso/islyd-asm

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