Clarify bssl-sys build instructions.
Change-Id: Ic25803634289d53fd2431cdb525cfe3fe08a753a
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/76607
Commit-Queue: Cindy Lin <cinlin@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
diff --git a/rust/bssl-sys/README.md b/rust/bssl-sys/README.md
index 13b7290..c0fb610 100644
--- a/rust/bssl-sys/README.md
+++ b/rust/bssl-sys/README.md
@@ -7,8 +7,12 @@
`bssl-sys` uses `bindgen` as part of the cmake build process to generate Rust compatibility shims for the targeted platform. It is important to generate it for the correct platform because `bindgen` uses LLVM information for alignment which varies depending on architecture.
### To Use
-1. Build `boringssl` with `-DRUST_BINDINGS=<rust-triple>`, which should match the [Rust target triple](https://doc.rust-lang.org/nightly/rustc/platform-support.html) when building `bssl-sys`,
-2. install `bindgen`, and
-3. install [`cargo-deny`](https://github.com/EmbarkStudios/cargo-deny).
+1. Build `boringssl` with `-DRUST_BINDINGS=<rust-triple>`, which should match the [Rust target triple](https://doc.rust-lang.org/nightly/rustc/platform-support.html) when building `bssl-sys`. For example, to build on 64-bit Linux:
-After that, the `bssl-sys` crate can be built. By default, it looks for `bindgen` output and BoringSSL static libraries in the `build` directory. This can be reconfigured with `BORINGSSL_BUILD_DIR` environment variable. Note the environment variable is evaluated relative to `rust/bssl-sys/src`, so using an absolute path may be more convenient.
+ cmake -GNinja -B build -DRUST_BINDINGS=x86_64-unknown-linux-gnu
+ ninja -C build
+
+2. Install `bindgen`.
+3. Install [`cargo-deny`](https://github.com/EmbarkStudios/cargo-deny).
+
+After that, the `bssl-sys` crate can be built via `cargo`. By default, it looks for `bindgen` output and BoringSSL static libraries in the `build` directory. This can be reconfigured with `BORINGSSL_BUILD_DIR` environment variable. Note the environment variable is evaluated relative to `rust/bssl-sys/src`, so using an absolute path may be more convenient.
