change the length of GPRS, all more control registers

[mlabaf2]

Before start

• 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。
• 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。
• 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

Hi
I want to extent length of GPRs registers to 128 or 129 bits (especially register files for integer section) but I cannot find where is the definition in Xiangshan code, comit a455b9f714df264edb679c81c3d6c74625ea3d82 ? I find len parameter in regfile.scala but cannot find where len is initialize.
also I see genregfile in schaduler.scala, is it the place to specify length of GPRS?
how can I extend length of data bus to support change of register file length?
Also, I cannot find how GPRs are connected to FunctionUnitInput and FuOutput in functionUnit.scala?
thank you for the response