37 lines
1.9 KiB
TeX
37 lines
1.9 KiB
TeX
In early 2018, more than a year before the official start of the project, after
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searching for a subject for the diploma thesis, the idea of building a computer
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from scratch had come up. Multiple suggestions on how to implement it were
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gathered. Originally, the goal was to
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design a computer consisting of seperate plug-in cards, one instruction
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residing on each. This would open up the ``black box`` of modern processor
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design, showing the basic components at a macroscopic scale.
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The project's aim was later
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redirected due to concerns about difficulty, and an FPGA-based design was opted
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for instead. After
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several months of implementation time, the project was split into two parts: the
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peripherals and the processor core. During the development process, and to get
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back to the original goal of making a processor more understandable, the
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peripherals changed from being implemented in VHDL back to hardware.
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This increased the required effort, but would result in a far more
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understandable final product.
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The decision to use a RISC-V based processor was made at the beginning of the
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project because the core architecture is well documented and modular, and because
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almost any feature not implemented inside the processor can be emulated using
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software instead.
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\subsection{Free software}
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\label{sec:free-software}
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For most of today's processors, documentation only exists on the execution of
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programs (the runtime environment), not for their internals. In order to have
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the biggest
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possible educational potential, this project is entirely "Free as in speech":
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All involved software and hardware designs, as well as all the tools and
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utilities required to create them, comply with the Free Software Foundation's
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definition for Free software~\cite{fsf-definition}. They give the users the
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rights to share, study and modify them at their will. In this thesis, the
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capital-F ``Free'' is used to refer to this definition rather than the
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meaning of ``free of charge'' or ``gratis''.
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