From ff6299dd77775815a3ddd677beb5b2b4ef5e4e1d Mon Sep 17 00:00:00 2001
From: Joe Richey <joerichey@google.com>
Date: Tue, 18 Feb 2020 22:45:02 -0800
Subject: [PATCH] cpu: Add support for CPU-based randomness

This allows freestanding targets to use getrandom.

Signed-off-by: Joe Richey <joerichey@google.com>
---
 Cargo.toml | 2 ++
 src/lib.rs | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/Cargo.toml b/Cargo.toml
index b576b84..0488cc1 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -35,6 +35,8 @@ wasi = "0.9"
 
 [features]
 std = []
+# Feature to enable fallback CPU-based implementation
+cpu = []
 # Feature to enable custom RNG implementations
 custom = []
 # Unstable feature to support being a libstd dependency
diff --git a/src/lib.rs b/src/lib.rs
index a19ed71..db8665b 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -185,6 +185,8 @@ cfg_if! {
         #[path = "rdrand.rs"] mod imp;
     } else if #[cfg(feature = "custom")] {
         use custom as imp;
+    } else if #[cfg(all(feature = "cpu", target_arch = "x86_64"))] {
+        #[path = "rdrand.rs"] mod imp;
     } else {
         compile_error!("\
             target is not supported, for more information see: \