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[f-cpu] the ghdl bomb


Even though it has not been tested and validated by the
F-CPU team, the announcement of GHDL is a very good news.

Usually, "software people" don't like VHDL because "it is slow"
and a C version of the source code has been started. This
increases the size of the project because two versions of the
sources must be written, maintained and checked against each others. The availability of a native GCC support reduces the
need of a C version of the code and reduces the coding, testing
and regression check efforts. This also provides a high
speed simulation engine that doesn't require contributors
to use extremely expensive proprietary software for the long
runs. Finally, it becomes possible to "execute" F-CPU as a
(mostly) standalone program.

it's a quick read and i am still amazed !
If this project existed 2 years ago, a lot of efforts
could have been spared (but they are worth anyway).

i did not try to run it yet but it's highly promising :
 - it's free software (though some runtime libraries
   are not completely GPL, they are copylefted or public domain)
 - it directly uses GCC -> no worry about intermediate
   representations or naughty C things (unlike Savant/FreeHDL)
 - Emphasis on VHDL LRM compliance (on sync with F-CPU)
 - Has already compiled LEON and DLX so the F-CPU core should
   require minimal changes
 - Communication is easy (Tristan lives near Paris, as several
   F-CPU contributors do)
 - KISS (Keep It Simple and Sexy ;-P)
 - and a few i forgot

The first thing that can be done is to check how the two
project coincide and how GHDL compiles the F-CPU VHDL code.
GHDL needs a few minor feature boosts to compile the testbenches
but the core itself should be ok. Support for GHDL is only
a minimal change to the existing, portable F-CPU sources
(if any).

Now, support for parallel (multi-CPU) computers is probably
not working (unlike Savant) but i'm sure it's only a matter
of time :-P Feature enhancements can be done by other people,
if they are interested or feel concerned.

I copy this mail to the Debian list because they once asked
how they could help. Now, this is a good way to start :-)
I encourage any Debian developer to contact the GHDL author
and propose his help.


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