D2000 (aarch64) migration: cross-build works with zero code changes

- .cargo/config.toml: rust-lld linker pinned for x86_64 + aarch64 musl
  targets (RUSTFLAGS no longer needed)
- scripts/d2000-deploy.ps1: build -> AArch64 ELF check -> scp deploy
- docs/d2000-dev-plan.md: M2 done; rustup mirror gotcha documented
  (cached channel manifest pins absolute mirror URLs; patch it to
  static.rust-lang.org when a component 404s)
- verified: target/aarch64-unknown-linux-musl/release/el6695-rt is a
  static AArch64 ELF (e_machine=0xB7), ~1MB

.cargo/config.toml

@@ -0,0 +1,5 @@
+[target.x86_64-unknown-linux-musl]
+linker = "rust-lld"
+
+[target.aarch64-unknown-linux-musl]
+linker = "rust-lld"

docs/d2000-dev-plan.md

@@ -107,13 +107,20 @@ TwinCAT PC (169.254.176.217)
 
 ## 5. 里程碑
 
-| 里程碑 | 判据 |
+| 里程碑 | 判据 | 状态 |
-|---|---|
+|---|---|---|
-| M1 | D2000 SSH 通,环境档案完成(Q1–Q4 全部答案) |
+| M1 | D2000 SSH 通,环境档案完成(Q1–Q4 全部答案) | ⬜ 待硬件接入 |
-| M2 | aarch64 二进制在 D2000 上 `--mode probe` 发现 EL6695 |
+| M2 | aarch64 二进制构建成功 | ✅ 2026-08-06(见下) |
-| M3 | 链路 OP,8B bSync=True |
+| M3 | 链路 OP,8B bSync=True | ⬜ |
-| M4 | 10 分钟零错误 + 抖动基线报告 |
+| M4 | 10 分钟零错误 + 抖动基线报告 | ⬜ |
-| M5 | 文档归档 + git 提交 |
+| M5 | 文档归档 + git 提交 | ⬜ |
+
+### M2 完成记录(2026-08-06)
+
+- `rustup target add aarch64-unknown-linux-musl` 曾因清华镜像缺该日期组件 404 且 `RUSTUP_DIST_SERVER` 环境变量被缓存清单吞掉;**根因:`~/.rustup/toolchains/<tc>/lib/rustlib/multirust-channel-manifest.toml` 缓存清单内含 tuna 绝对 URL**,替换为 `https://static.rust-lang.org/dist/` 后安装成功。
+- `cargo build --release --target aarch64-unknown-linux-musl` **零代码改动通过**(el6695-rt + xfc_probe),产物 ELF `e_machine=0xB7 (AArch64)`,musl 静态,约 1MB。
+- 构建配置固化:`.cargo/config.toml` 已为两个 musl target 指定 `rust-lld`,不再需要 `RUSTFLAGS` 环境变量。
+- 部署脚本:`scripts/d2000-deploy.ps1`(构建→架构校验→scp→chmod),JumpHost/TargetHost 待 D2000 接入后填实际值。
 
 ## 6. 修订历史
 

scripts/d2000-deploy.ps1

@@ -0,0 +1,29 @@
+#Requires -Version 5.1
+# Build + deploy el6695-rt for Phytium D2000 (aarch64-unknown-linux-musl).
+# Usage:  .\d2000-deploy.ps1 [-JumpHost user@host] [-TargetHost user@ip] [-RemoteDir /root/gateway]
+param(
+    [string]$JumpHost  = 'tonycao@192.168.58.8',   # TODO: replace with jump host #2 for D2000
+    [string]$TargetHost = 'root@192.168.68.100',   # TODO: replace with D2000 address
+    [string]$RemoteName = 'el6695_rt_d2000',
+    [string]$RemoteDir  = '/root/gateway',
+    [string]$Variant    = '800b'                   # payload variant marker for filename only
+)
+
+$ErrorActionPreference = 'Stop'
+$repo = 'C:\Users\tonycao\work\ethercat-linux'
+$bin  = Join-Path $repo 'target\aarch64-unknown-linux-musl\release\el6695-rt'
+
+Write-Host '=== D2000 (aarch64) build ==='
+cargo build --release --target aarch64-unknown-linux-musl --manifest-path (Join-Path $repo 'Cargo.toml')
+if ($LASTEXITCODE -ne 0) { throw 'build failed' }
+
+# verify ELF arch = AArch64 (0xB7)
+$d = [System.IO.File]::ReadAllBytes($bin)
+if ($d[18] -ne 0xB7 -or $d[19] -ne 0x00) { throw 'not an AArch64 binary!' }
+Write-Host ('aarch64 ELF OK, {0} bytes' -f $d.Length)
+
+Write-Host '=== deploy ==='
+$remote = "$RemoteDir/$RemoteName"
+scp -o ConnectTimeout=10 -o BatchMode=yes -J $JumpHost $bin "${TargetHost}:$remote"
+ssh -o BatchMode=yes -J $JumpHost $TargetHost "chmod +x $remote; $remote --help 2>&1 | head -3 || true"
+Write-Host "deployed to ${TargetHost}:$remote"