ucb-bar/chipyard

Try to speed up VCU118 SDCard loading

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#854 opened on 2021/04/14

 (1 件のコメント) (0 件のリアクション) (0 人の担当者)Scala (857 件のフォーク)batch import
enhancementhelp wanted

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説明

Impact: software

Description In order to get SDCard loading on the VCU118 working, we need to have a slow SPI divisor.

https://github.com/ucb-bar/chipyard/blob/45684f1b875f018a1945476cec9269068e1618ca/fpga/src/main/resources/vcu118/sdboot/sd.c#L175

However, it looks like the Freedom platform uses a faster div.

https://github.com/sifive/freedom/blob/b348a50d5d10ffa94ab2a07a33622b1c634a01ea/bootrom/sdboot/sd.c#L169

Why does this div not work? Can we find a middle ground?

What is a motivating example for changing the behavior?

Speed up Linux loading!

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