前言

DMA 作为 linux 驱动开发中 重要的一环，我会用 xilinx 的 zu2cg 开发板 实列进行讲解
DMA 大致的操作过程

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发送请求
应答无反应或应答失败
应答成功 发送存储器地址
没有传输完成 修改地址指针
是的传输完成
DMA请求
CPU应答请求
数据传送
传送完成?
DMA结束
  • 以上这个图只是最简单的dma 操作流程
  • 我在Xilinx 的资料库中找到一个概念图 linux dma framework
  • 大概的框架就如下面所示:

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