About the clock problem in Xiangshan

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Before start

• I have read the XiangShan Documents. 我已经阅读过香山文档。
• 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。
• 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。

Describe you problem

nanhuv2官网 https://docs.xiangshan.cc/zh-cn/latest/integration/fpga/fpga/ 生成的工程给的实际CPU时钟是50M，然后对应nanhuv2 https://docs.xiangshan.cc/zh-cn/latest/integration/docker/ 给的image里的dts设置的时钟如下图，给的是25M。这两者之间有没有什么联系？如果我想修改实际时钟，假如实际时钟修改为10M，那么dts里需要做相应的修改么？
The actual CPU clock of the project generated by the nanhuv2 official website https://docs.xiangshan.cc/zh-cn/latest/integration/fpga/fpga/ is 50M, and the clock set in the dts of the image given by nanhuv2 https://docs.xiangshan.cc/zh-cn/latest/integration/docker/ is 25M as shown below. Is there any connection between the two? If I want to modify the actual clock, if the actual clock is changed to 10M, do I need to make corresponding changes in the dts?

What did you do before

如上

Environment

• XiangShan branch:
• XiangShan commit id:
• NEMU commit id:
• SPIKE commit id:
• Operating System:
• gcc version:
• mill version:
• java version:

Additional context

No response

[cebarobot]

十分抱歉回复晚了。

• clkc 节点的 clock-frequency，应该是指 FPGA 提供的时钟源的频率。
• clint 节点的 clock-frequency-mhz 指的是 clint 的时钟源的频率，理论上影响 time 寄存器的更新频率。
  • 目前这个配置项可能已经废弃，请直接使用 cpus 节点的 timebase-frequency 项来配置。
  • 在仿真环境下，clint 送入的时钟是在主时钟分频得到的，FPGA 环境下可能需要检查一下具体的代码。
• cpus 下面的每个 cpu 节点都有一个 clock-frequency，它指的是 CPU 实际运行的频率，可以缺省为 0。

相对比较重要的是 cpus 节点的 timebase-frequency，因为它影响了操作系统计时的准确性。对于较老的 Kernel，也建议同时修改 clint 节点的 clock-frequency-mhz。

Sorry for late reply.

• clock-frequency in node clkc is the frequency of FPGA clock.
• clock-frequency-mhz in node clint is the frequency of clint clock, which influences the frequency of the update of time CSR.
  • clock-frequency-mhz may be deprecated in latest kernel. Please consider use timebase-frequency in node cpus.
  • In software emulation environment, clint clock is divided from main clock. You'd better to check the source code.
• clock-frequency in every cpu node under cpus is the frequency of every processor core, and could be default 0.

timebase-frequency in node cpus is important, which influences the accuracy of Operating System time count. For older kernel, modification of clock-frequency-mhz in node clint is also required.

[LOCKEDGATE]

十分感谢，我尝试一下
Thanks a lot ，I'll try it.