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0.1.0 090201 jb@orsoc.se
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0.1.0 090201 jb@orsoc.se
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0.1.1 090304 jb@orsoc.se
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0.1.1 090304 jb@orsoc.se
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0.1.2 090511 jb@orsoc.se
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0.1.2 090511 jb@orsoc.se
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0.1.3 090604 jb@orsoc.se
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0.1.3 090604 jb@orsoc.se
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0.1.4 090828 jb@orsoc.se
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0.1.4 090828 jb@orsoc.se
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0.1.5 090903 jb@orsoc.se
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===============================================================================
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===============================================================================
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-- Installation --
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-- Installation --
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===============================================================================
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===============================================================================
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The OR debug proxy application runs on multiple platforms only requiring
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The OR debug proxy application runs on multiple platforms only requiring
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Line 324... |
noticing that, over a 4-odd megabyte transfer from GDB, taking about 4
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noticing that, over a 4-odd megabyte transfer from GDB, taking about 4
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minutes, the proxy only executed for 2.5 seconds, and the three most
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minutes, the proxy only executed for 2.5 seconds, and the three most
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used functions, accounting for 50% of execution were functions in the
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used functions, accounting for 50% of execution were functions in the
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driver. This indicates that either better use of, or better
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driver. This indicates that either better use of, or better
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implementation of, the driver could dramatically increase speed.
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implementation of, the driver could dramatically increase speed.
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SOLVED: It appears increasing the packet size of the GDB transfers can
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achieve a significant increase in speed. GDB queries the proxy at when
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it connects about its maximum packet size. It was previously 255 bytes
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and this meant larger downloads were "slow". Raising this transfer size
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to around 4kB (4096 bytes) resulted in a throughput increase of almost
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10-times. This is due to the fact that most of the transfer time is
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spent on waiting for the driver - the overhead per call is significant
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if only transferring 255 bytes, so increasing the amount per transfer
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reduces the amount of time waiting for the driver to perform the trans-
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action. Sizes greater than 4kB, for some reason, cause the driver to
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have issues - resulting in incorrect CRC reading and bad Status returns
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from the driver functions. Why this is so should be investigated.
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* USB<->JTAG Driver TODO:
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* USB<->JTAG Driver TODO:
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Get the latest version of the MPSSE function code (from
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Get the latest version of the MPSSE function code (from
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http://ftdichip.com/Projects/MPSSE/FTCJTAG/FTCJTAG_Source.zip at last
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http://ftdichip.com/Projects/MPSSE/FTCJTAG/FTCJTAG_Source.zip at last
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check) and update our Linux compatible version with the ones here. This
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check) and update our Linux compatible version with the ones here. This
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might provide improved stability or performance, but from the list of
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might provide improved stability or performance, but from the list of
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