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The generic memcpy routine provided in kernel does only byte copies. Using word copies we can lower boot time and cycles spend in memcpy quite significantly. Booting on my de0 nano I see boot times go from 7.2 to 5.6 seconds. The avg cycles in memcpy during boot go from 6467 to 1887. I tested several algorithms (see code in previous patch mails) The implementations I tested and avg cycles: - Word Copies + Loop Unrolls + Non Aligned 1882 - Word Copies + Loop Unrolls 1887 - Word Copies 2441 - Byte Copies + Loop Unrolls 6467 - Byte Copies 7600 In the end I ended up going with Word Copies + Loop Unrolls as it provides best tradeoff between simplicity and boot speedups. Signed-off-by: Stafford Horne <shorne@gmail.com>
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611 B
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13 lines
611 B
Plaintext
The OpenRISC Linux port is fully functional and has been tracking upstream
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since 2.6.35. There are, however, remaining items to be completed within
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the coming months. Here's a list of known-to-be-less-than-stellar items
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that are due for investigation shortly, i.e. our TODO list:
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-- Implement the rest of the DMA API... dma_map_sg, etc.
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-- Finish the renaming cleanup... there are references to or32 in the code
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which was an older name for the architecture. The name we've settled on is
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or1k and this change is slowly trickling through the stack. For the time
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being, or32 is equivalent to or1k.
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