About SDCard module

[changekkk]

Before start

• [X] I have read the RISC-V ISA Manual and this is not a RISC-V ISA question. 我已经阅读过 RISC-V 指令集手册，这不是一个指令集相关的问题。
• [X] I have read the XiangShan Documents. 我已经阅读过香山文档。
• [X] I have searched the previous issues and did not find anything relevant. 我已经搜索过之前的 issue，并没有找到相关的。
• [X] I have searched the previous discussions and did not find anything relevant. 我已经搜索过之前的 discussions，并没有找到相关的。
• [X] I have reviewed the commit messages from the relevant commit history. 我已经浏览过相关的提交历史和提交信息。

Describe the question

你好，看到咱们difftest使用了基于AXI接口的SDCard模型，这个是自主开发的模块还是开源模块？另外，想问下咱们是有能够支持SPI接口的SDCard模型？

[TRANSLATION] Hello, I noticed that our difftest uses an SDCard model based on the AXI interface. Is this module self-developed or an open-source module? Also, I would like to ask if we have an SDCard model that supports the SPI interface.

[cebarobot]

我们的 SDCard 模块是我们自己开发并开源的模块，仅限于仿真，并不能用于 FPGA、综合等真实场景。我们没有支持 SPI 接口的 SDCard 模型。

Our SDCard module is developed and open-sourced by our team. It's only used for emulation, not for FPGA or synthesis. We don't have any SDCard module which support SPI interface.