From 03bfd901f8188761c7454725d026a0b5b675de2f Mon Sep 17 00:00:00 2001
From: Sean Cross <sean@xobs.io>
Date: Sun, 27 Sep 2020 11:49:02 +0800
Subject: [PATCH] lib: fix `no_std` compiling

Add a conditional check to enable `no_std` if the target_os is "none".

Signed-off-by: Sean Cross <sean@xobs.io>
---
 src/lib.rs | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/src/lib.rs b/src/lib.rs
index 9fb74b7..306ac5d 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,4 +1,5 @@
-use std::convert::TryInto;
+#![cfg_attr(target_os = "none", no_std)]
+use core::convert::TryInto;
 pub struct Register {
     /// Offset of this register within this CSR
     offset: usize,
@@ -78,7 +79,7 @@ pub struct CSR<T> {
 
 impl<T> CSR<T>
 where
-    T: std::convert::TryFrom<usize> + std::convert::TryInto<usize> + std::default::Default,
+    T: core::convert::TryFrom<usize> + core::convert::TryInto<usize> + core::default::Default,
 {
     pub fn new(base: *mut T) -> Self {
         CSR { base }
@@ -131,11 +132,11 @@ mod tests {
     #[test]
     fn compile_check() {
         use super::*;
-        let mut audio = CSR::new(0x0000_0000 as *mut u32);
+        let mut audio = CSR::new(0x1000_0000 as *mut u32);
         audio.r(pac::audio::RX_CTL_ENABLE);
         audio.rw(pac::audio::RX_CTL_RESET, 1);
 
-        let mut uart = CSR::new(0x0001_0000 as *mut u8);
+        let mut uart = CSR::new(0x1001_0000 as *mut u8);
         uart.ow(pac::uart::RXTX_RXTX, b'a');
         assert_ne!(uart.r(pac::uart::TXFULL_TXFULL), 1);