Feat/xuantie c908x

[goodnorning]

拉取/合并请求描述：(PR description)

为什么提交这份PR (why to submit this PR)

Support XuanTie c908x serial processors

你的解决方案是什么 (what is your solution)

Support XuanTie c908x serial processors

请提供验证的bsp和config (provide the config and bsp)

• BSP:
  bsp/xuantie/xiaohui/c908x

当前拉取/合并请求的状态 Intent for your PR

必须选择一项 Choose one (Mandatory):

• 本拉取/合并请求是一个草稿版本 This PR is for a code-review and is intended to get feedback
• 本拉取/合并请求是一个成熟版本 This PR is mature, and ready to be integrated into the repo

代码质量 Code Quality：

我在这个拉取/合并请求中已经考虑了 As part of this pull request, I've considered the following:

• 已经仔细查看过代码改动的对比 Already check the difference between PR and old code
• 代码风格正确，包括缩进空格，命名及其他风格 Style guide is adhered to, including spacing, naming and other styles
• 没有垃圾代码，代码尽量精简，不包含#if 0代码，不包含已经被注释了的代码 All redundant code is removed and cleaned up
• 所有变更均有原因及合理的，并且不会影响到其他软件组件代码或BSP All modifications are justified and not affect other components or BSP
• 对难懂代码均提供对应的注释 I've commented appropriately where code is tricky
• 代码是高质量的 Code in this PR is of high quality
• 已经使用formatting 等源码格式化工具确保格式符合RT-Thread代码规范 This PR complies with RT-Thread code specification
• 如果是新增bsp, 已经添加ci检查到.github/ALL_BSP_COMPILE.json 详细请参考链接BSP自查

[github-actions]

👋 感谢您对 RT-Thread 的贡献！Thank you for your contribution to RT-Thread!

为确保代码符合 RT-Thread 的编码规范，请在你的仓库中执行以下步骤运行代码格式化工作流（如果格式化CI运行失败）。
To ensure your code complies with RT-Thread's coding style, please run the code formatting workflow by following the steps below (If the formatting of CI fails to run).

---

🛠 操作步骤 | Steps

1. 前往 Actions 页面 | Go to the Actions page
   点击进入工作流 → | Click to open workflow →

2. 点击 Run workflow | Click Run workflow

• 设置需排除的文件/目录（目录请以"/"结尾）
  Set files/directories to exclude (directories should end with "/")
• 将目标分支设置为 \ Set the target branch to：feat/xuantie_c908x
• 设置PR number为 \ Set the PR number to：11219

3. 等待工作流完成 | Wait for the workflow to complete
   格式化后的代码将自动推送至你的分支。
   The formatted code will be automatically pushed to your branch.

完成后，提交将自动更新至 feat/xuantie_c908x 分支，关联的 Pull Request 也会同步更新。
Once completed, commits will be pushed to the feat/xuantie_c908x branch automatically, and the related Pull Request will be updated.

如有问题欢迎联系我们，再次感谢您的贡献！💐
If you have any questions, feel free to reach out. Thanks again for your contribution!

[github-actions]

📌 Code Review Assignment

🏷️ Tag: workflow

Reviewers: Rbb666 kurisaW supperthomas

Changed Files (Click to expand)

• .github/ALL_BSP_COMPILE.json

---

📊 Current Review Status (Last Updated: 2026-02-25 17:26 CST)

• ⌛ Rbb666 Pending Review
• ⌛ kurisaW Pending Review
• ⌛ supperthomas Pending Review

---

📝 Review Instructions

1. 维护者可以通过单击此处来刷新审查状态: 🔄 刷新状态
   Maintainers can refresh the review status by clicking here: 🔄 Refresh Status

2. 确认审核通过后评论 LGTM/lgtm
   Comment LGTM/lgtm after confirming approval

3. PR合并前需至少一位维护者确认
   PR must be confirmed by at least one maintainer before merging

ℹ️ 刷新CI状态操作需要具备仓库写入权限。
ℹ️ Refresh CI status operation requires repository Write permission.

[Copilot]

Pull request overview

This PR introduces a new RT-Thread BSP for the XuanTie XiaoHui c908x platform, including build scripts, configuration, board init, and the corresponding low-level startup/interrupt/trap implementation in the XuanTie dummy chip library. It also registers the BSP in CI compile list.

Changes:

• Add new BSP directory bsp/xuantie/xiaohui/c908x with RT-Thread config, SCons build entrypoints, board init, and documentation.
• Add c908x CPU support files under bsp/xuantie/libraries/.../chip_riscv_dummy/src/arch/c908x/ (startup, vectors, trap, system).
• Update .github/ALL_BSP_COMPILE.json to include xuantie/xiaohui/c908x.

Reviewed changes

Copilot reviewed 28 out of 32 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
bsp/xuantie/xiaohui/c908x/utilities/gdb.init	Adds GDB init script used by the BSP project/debug setup.
bsp/xuantie/xiaohui/c908x/template.cdkws	Adds CDK workspace template for the BSP.
bsp/xuantie/xiaohui/c908x/template.cdkproj	Adds CDK project template (build/debug settings).
bsp/xuantie/xiaohui/c908x/rtconfig_preinc.h	Adds generated pre-include configuration macros for toolchain/build.
bsp/xuantie/xiaohui/c908x/rtconfig.py	Adds GCC toolchain configuration and flags for c908x.
bsp/xuantie/xiaohui/c908x/rtconfig.h	Adds RT-Thread Kconfig-generated build configuration header.
bsp/xuantie/xiaohui/c908x/qemu.bat	Adds Windows helper script to run QEMU for this BSP.
bsp/xuantie/xiaohui/c908x/objdump.bat	Adds Windows helper script to disassemble the built ELF.
bsp/xuantie/xiaohui/c908x/figures/1.env.png	Adds documentation screenshot used by README.
bsp/xuantie/xiaohui/c908x/board/board.h	Adds board feature macros and board init API declarations.
bsp/xuantie/xiaohui/c908x/board/board.c	Adds rt_hw_board_init() implementation for RT-Thread startup.
bsp/xuantie/xiaohui/c908x/board/SConscript	Adds SCons build rules for the board layer.
bsp/xuantie/xiaohui/c908x/board/Kconfig	Adds BSP-specific Kconfig options (UART/FPU).
bsp/xuantie/xiaohui/c908x/applications/main.c	Adds sample main() entry for the BSP.
bsp/xuantie/xiaohui/c908x/applications/SConscript	Adds SCons build rules for applications.
bsp/xuantie/xiaohui/c908x/SConstruct	Adds top-level SCons build entry for the BSP.
bsp/xuantie/xiaohui/c908x/SConscript	Adds module compilation script to include subcomponents.
bsp/xuantie/xiaohui/c908x/README.md	Adds BSP documentation (features, toolchain links, QEMU run/debug).
bsp/xuantie/xiaohui/c908x/Kconfig	Adds BSP root Kconfig wiring into RT-Thread Kconfig tree.
bsp/xuantie/xiaohui/c908x/.settings/projcfg.ini	Adds RT-Thread Studio/Eclipse project settings for the BSP.
bsp/xuantie/xiaohui/c908x/.settings/org.eclipse.core.runtime.prefs	Adds Eclipse runtime prefs for the BSP project.
bsp/xuantie/xiaohui/c908x/.project	Adds Eclipse project metadata.
bsp/xuantie/xiaohui/c908x/.config	Adds default defconfig for the BSP.
bsp/xuantie/libraries/xuantie_libraries/chip_riscv_dummy/src/arch/c908x/vectors.S	Adds interrupt/trap/handler assembly for c908x.
bsp/xuantie/libraries/xuantie_libraries/chip_riscv_dummy/src/arch/c908x/trap_c.c	Adds C-side trap dump/exception handler glue.
bsp/xuantie/libraries/xuantie_libraries/chip_riscv_dummy/src/arch/c908x/system.c	Adds c908x SystemInit, cache/PLIC/tick init, feature enables.
bsp/xuantie/libraries/xuantie_libraries/chip_riscv_dummy/src/arch/c908x/startup.S	Adds reset/startup vectors and stack setup for c908x.
bsp/xuantie/libraries/xuantie_libraries/chip_riscv_dummy/src/arch/c908x/SConscript	Registers c908x arch sources in SCons.
.github/ALL_BSP_COMPILE.json	Adds the BSP to CI BSP compile matrix.

[Copilot]

[custom/自定义]: PR title prefix format does not follow RT-Thread convention

English: PR title should use a lowercase prefix like [module][subsystem] Description. Current title "Feat/xuantie c908x" doesn’t match the required bracketed prefix pattern. Suggested: [xuantie][bsp] Add xiaohui c908x BSP (or similar that matches the touched paths).
中文：PR 标题应使用小写的前缀格式：[模块][子系统] 描述。当前标题 "Feat/xuantie c908x" 不符合方括号前缀规范。建议：[xuantie][bsp] Add xiaohui c908x BSP（或其它与修改路径匹配的标题）。

[Copilot]

[documentation/文档]: PR description still contains the template wrapper brackets

English: The PR description still includes the surrounding [ ... ] template wrapper text, which the template says must be replaced/removed; this typically blocks merging in RT-Thread’s PR process. Please update the PR description to remove the template wrapper and keep only the filled-in sections (What/Why/How + test/verification info).
中文：PR 描述中仍保留了模板要求替换/删除的 [ ... ] 外层包裹内容（模板提示不替换会导致无法合并）。请更新 PR 描述，移除模板包裹，仅保留已填写的 What/Why/How 以及测试/验证信息。