rp/multicore: enable fpu on second core only if building for -eabihf …

…targets.

embassy-rp/build.rs

@@ -15,5 +15,10 @@ fn main() {
 
         println!("cargo:rerun-if-changed=build.rs");
         println!("cargo:rerun-if-changed=link-rp.x.in");
+
+        println!("cargo:rustc-check-cfg=cfg(has_fpu)");
+        if target.ends_with("-eabihf") {
+            println!("cargo:rustc-cfg=has_fpu");
+        }
     }
 }

embassy-rp/src/multicore.rs

@@ -170,7 +170,7 @@ where
         };
 
         // Enable FPU
-        #[cfg(feature = "_rp235x")]
+        #[cfg(all(feature = "_rp235x", has_fpu))]
         unsafe {
             let p = cortex_m::Peripherals::steal();
             p.SCB.cpacr.modify(|cpacr| cpacr | (3 << 20) | (3 << 22));