Question

今天开始我在CS140e上的工作时，我已经完成了该项目的第3阶段（编写C代码以直接与Raspberry Pi 3上的GPIO引脚进行对话，这只会使LED闪烁），但是在第4阶段，一旦我尝试在Rust中编译我的解决方案，rustc似乎无法找到aarch64-none-elf目标：

➜  phase4 git:(master) ✗ make
+ Building target/aarch64-none-elf/release/libblinky.a [xargo --release]
WARNING: the sysroot can't be built for the Stable channel. Switch to nightly.
warning: `panic` setting is ignored for `test` profile
   Compiling rlibc v1.0.0
error[E0463]: can't find crate for `core`
  |
  = note: the `aarch64-none-elf` target may not be installed

error: aborting due to previous error

For more information about this error, try `rustc --explain E0463`.
error: Could not compile `rlibc`.

To learn more, run the command again with --verbose.
Makefile:35: recipe for target 'target/aarch64-none-elf/release/libblinky.a' failed
make: *** [target/aarch64-none-elf/release/libblinky.a] Error 101

，实际上rustc --print target-list不包括aarch64-none-elf：

➜  phase4 git:(master) ✗ rustc --print target-list
aarch64-linux-android
aarch64-unknown-cloudabi
aarch64-unknown-freebsd
aarch64-unknown-fuchsia
aarch64-unknown-linux-gnu
aarch64-unknown-linux-musl
aarch64-unknown-openbsd
        ...

尽管我已经安装了工具链：

➜  phase4 git:(master) ✗ whereis aarch64-none-elf-gcc
aarch64-none-elf-gcc: /usr/local/bin/aarch64-none-elf/bin/aarch64-none-elf-gcc

此外，我还有一个名为aarch64-none-elf.json的自定义目标文件，其中包含以下内容（在构建时可能会传递给xargo）：

{
  "abi-blacklist": [
    "stdcall",
    "fastcall",
    "vectorcall",
    "thiscall",
    "win64",
    "sysv64"
  ],
  "arch": "aarch64",
  "data-layout": "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128",
  "executables": true,
  "linker": "aarch64-none-elf-ld",
  "linker-flavor": "ld",
  "linker-is-gnu": true,
  "llvm-target": "aarch64-unknown-none",
  "no-compiler-rt": true,
  "features": "+a53,+strict-align",
  "max-atomic-width": 128,
  "os": "none",
  "panic": "abort",
  "panic-strategy": "abort",
  "position-independent-executables": true,
  "target-c-int-width": "32",
  "target-endian": "little",
  "target-pointer-width": "64",
  "disable-redzone": true
}

Answer 1

原来我需要做的就是运行rustup default nightly并使用rustc的夜间版本，如警告中所述，我能够克服该错误。如果有人想解释为什么，那就太好了。

➜  phase4 git:(master) ✗ rustc --version
rustc 1.30.0-nightly (33b923fd4 2018-08-18)

如何在我的Rust工具链中添加`aarch64-none-elf`？

1 个答案: