Try to speed up VCU118 SDCard loading · ucb-bar/chipyard

(1 則留言) (0 個反應) (0 位負責人)Scala (857 個分叉)batch import

enhancementhelp wanted

倉庫指標

星標: (2,255 顆星)
PR 合併指標: (平均合併 13天 17小時) (30 天內合併 4 個 PR)

描述

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!

貢獻者指南

研究方向: 比較VCU118和Freedom平台之間的SPI分頻值和時序特性。測量實際SPI時鐘速度並調試為什麼更快的分頻器失敗。
技術棧: c
領域: performance
議題類型: 效能
難度: 3
預計時間: 半天
活動狀態: 活躍
清晰度: 清晰
前置要求: CSPIembedded systems
新手友善度: 30