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

(1 条评论) (0 个反应) (0 位负责人)Scala (857 个派生)batch import

enhancementhelp wanted

仓库指标

星标: (2,255 个星标)
PR 合并指标: (平均合并 13天 17小时) (30 天内合并 4 个 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!

贡献者指南

研究方向: 比较VCU118和Freedom平台之间的SPI分频值和时序特性。测量实际SPI时钟速度并调试为什么更快的分频器失败。
技术栈: c
领域: performance
议题类型: 性能
难度: 3
预计时间: 半天
活动状态: 活跃
清晰度: 清晰
前置要求: CSPIembedded systems
新手友好度: 30