mirror of https://github.com/openXC7/prjxray.git
68 lines
2.5 KiB
ReStructuredText
68 lines
2.5 KiB
ReStructuredText
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============
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Introduction
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============
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`Project X-Ray`_ documents the `Xilinx`_ 7-Series FPGA architecture to enable
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the development of open-source tools. Our goal is to provide sufficient information
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to develop a free and open Verilog to bitstream toolchain for these devices.
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The project is a part of SymbiFlow Toolchain. `SymbiFlow`_ uses the obtained
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information about the chip in `Architecture Definitions`_ project, which
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allows for creating bitstreams for many architectures including 7-Series devices.
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Collected information
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---------------------
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To allow the usage of Xilinx FPGAs in SymbiFlow toolchain we collect some
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important data about the Xilinx chips. The needed information includes:
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- Architecture description:
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* chip internals
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* timings
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- Bitstream format:
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* metadata (i.e. header, crc)
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* configuration bits
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Final results are stored in the database which is further used by the
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`Architecture Definitions`_ project. The whole database is described in
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the dedicated :doc:`chapter <format/index>`.
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Methodology
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-----------
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The most important element of the project are fuzzers - scripts responsible
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for obtaining information about the chips. Their name comes from the fact that
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they use a similar idea to `Fuzz testing`_. Firstly, they generate a huge
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amount of designs in which the examined chip property is either enabled or
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disabled. By comparing the differences in the final bitstream obtained
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from vendor tools, we can detect relations between bits in the bitstream and
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provided functionalities.
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However, some of the fuzzers works differently, i.e. they just creating
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the database structure, the whole idea is similar and rely on the output produced
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by the vendor tools.
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All fuzzers are described in the dedicated :doc:`chapter <db_dev_process/fuzzers/index>`.
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.. _Fuzz testing: https://en.wikipedia.org/wiki/Fuzzing
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Important Parts
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---------------
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The important parts of the `Project X-Ray` are:
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- *minitests* - designs that can be viewed by a human in Vivado to better
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understand how to generate more useful designs.
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- *experiments* - similar to *minitests* except for the fact that they are only
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useful for a short time.
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- *tools & libs* - they convert the resulting bitstreams into various formats.
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- *utils* - tools that are used but still require some testing
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.. _Project X-Ray: https://github.com/SymbiFlow/prjxray
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.. _Xilinx: http://www.xilinx.com/
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.. _SymbiFlow: https://symbiflow.readthedocs.io/
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.. _Architecture Definitions: https://github.com/SymbiFlow/symbiflow-arch-defs
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