Merge pull request #10 from rust-embedded/new-asm

Update to new assembly syntax. Create release v0.3.0.

CHANGELOG.md

@@ -7,14 +7,23 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [Unreleased]
 
+## [v0.3.0] - 2022-01-25
+
 ### Changed
-- Bumped `bare-metal` to version `1.0.0`.
+- Bumped `bare-metal` to version `1.0.0`. Using bare_metal v1.x causes
+incompatible type errors with device crates (PACs) using bare-metal v0.2.x.
+This, _among other removed features_, requires a major version bump to fix.
+- All uses of the `llvm_asm!` macro have been replaced with `asm!`, in
+accordance with [Issue 92816](https://github.com/rust-lang/rust/pull/92816).
 
 ### Removed
 - `enable_cs` removed due to soundness hole when interacting with `Clone` and
   `interrupt::free`.
 - Remove `peripherals` module since the peripheral API is no longer provided by
   `bare-metal`.
+- `register::{sp, pc}::write` have been removed; inline assembly [mandates](https://doc.rust-lang.org/nightly/reference/inline-assembly.html#rules-for-inline-assembly)
+  that the stack pointer is restored before leaving an asm block. Writing
+  PC is also being removed as a precaution.
 
 ## [v0.2.2] - 2020-04-23
 
@@ -50,7 +59,8 @@ Initial release.
 
 [bare-metal]: https://github.com/japaric/bare-metal
 
-[Unreleased]: https://github.com/rust-embedded/msp430/compare/v0.2.2...HEAD
+[Unreleased]: https://github.com/rust-embedded/msp430/compare/v0.3.0...HEAD
+[v0.3.0]: https://github.com/rust-embedded/msp430/compare/v0.2.2...v0.3.0
 [v0.2.2]: https://github.com/rust-embedded/msp430/compare/v0.2.1...v0.2.2
 [v0.2.1]: https://github.com/rust-embedded/msp430/compare/v0.2.0...v0.2.1
 [v0.2.0]: https://github.com/rust-embedded/msp430/compare/v0.1.0...v0.2.0

README.md

@@ -7,10 +7,15 @@
 
 This crate is based on [cortex-m](https://docs.rs/cortex-m) crate by Jorge Aparicio (@japaric).
 
-**This crate requires a nightly rust due to the use of the `llvm_asm!`
-(`0.2.2` and above) or `asm!` (`0.2.1` and below) macro.** For `0.2.2`,
-`nightly-2020-04-22` is known to work. For `0.2.1`, `nightly-2020-01-04` is
-known to work.
+**This crate requires a nightly rust due to the use of the new `asm!` (`0.3.0`
+and above), `llvm_asm!` (`0.2.2`) or old `asm!` (`0.2.1` and below) macros.**
+The below table contains compilers which are known to work:
+
+|`msp430` version|`rustc` compiler    |
+|----------------|--------------------|
+|`0.3.0`         |`nightly-2022-01-24`|
+|`0.2.2`         |`nightly-2020-04-22`|
+|`0.2.1`         |`nightly-2020-01-04`|
 
 ## [Documentation](https://docs.rs/crate/msp430)
 

src/asm.rs

@@ -1,21 +1,19 @@
 //! Miscellaneous assembly instructions
 
+use crate::asm;
+
 /// A no-operation. Useful to prevent delay loops from being optimized away.
 #[inline(always)]
 pub fn nop() {
     unsafe {
-        llvm_asm!("nop"
-             :
-             :
-             :
-             : "volatile");
+        asm!("nop");
     }
 }
 
 /// A compiler fence, prevents instruction reordering.
 #[inline(always)]
 pub fn barrier() {
     unsafe {
-        llvm_asm!("" ::: "memory" : "volatile");
+        asm!("");
     }
 }

src/interrupt.rs

@@ -1,5 +1,7 @@
 //! Interrupts
 
+use crate::asm;
+
 pub use bare_metal::{CriticalSection, Mutex};
 
 /// Disables all interrupts
@@ -8,11 +10,7 @@ pub fn disable() {
     match () {
         #[cfg(target_arch = "msp430")]
         () => unsafe {
-            llvm_asm!("dint { nop"
-                 :
-                 :
-                 : "memory"
-                 : "volatile");
+            asm!("dint {{ nop");
         },
         #[cfg(not(target_arch = "msp430"))]
         () => {}
@@ -31,11 +29,7 @@ pub unsafe fn enable() {
     match () {
         #[cfg(target_arch = "msp430")]
         () => {
-            llvm_asm!("nop { eint { nop"
-                 :
-                 :
-                 : "memory"
-                 : "volatile");
+            asm!("nop {{ eint {{ nop");
         }
         #[cfg(not(target_arch = "msp430"))]
         () => {}

src/lib.rs

@@ -10,9 +10,11 @@
 //! - Safe wrappers around assembly instructions like `nop`
 
 #![deny(missing_docs)]
-#![feature(llvm_asm)]
+#![feature(asm_experimental_arch)]
 #![no_std]
 
+use core::arch::asm;
+
 extern crate bare_metal;
 
 #[macro_use]

src/register/pc.rs

@@ -1,25 +1,13 @@
 //! Program counter
 
+use crate::asm;
+
 /// Reads the CPU register
 #[inline(always)]
 pub fn read() -> u16 {
     let r;
     unsafe {
-        llvm_asm!("mov R0,$0"
-             : "=r"(r)
-             :
-             :
-             : "volatile");
+        asm!("mov R0, {0}", out(reg) r);
     }
     r
 }
-
-/// Writes `bits` to the CPU register
-#[inline(always)]
-pub unsafe fn write(bits: u16) {
-    llvm_asm!("mov $0,R0"
-         :
-         : "r"(bits)
-         :
-         : "volatile");
-}

src/register/sp.rs

@@ -1,25 +1,13 @@
 //! Main Stack Pointer
 
+use crate::asm;
+
 /// Reads the CPU register
 #[inline(always)]
 pub fn read() -> u16 {
     let r;
     unsafe {
-        llvm_asm!("mov R1,$0"
-             : "=r"(r)
-             :
-             :
-             : "volatile");
+        asm!("mov R1, {0}", out(reg) r);
     }
     r
 }
-
-/// Writes `bits` to the CPU register
-#[inline(always)]
-pub unsafe fn write(bits: u16) {
-    llvm_asm!("mov $0,R1"
-         :
-         : "r"(bits)
-         :
-         : "volatile");
-}

src/register/sr.rs

@@ -1,5 +1,7 @@
 //! Status Register
 
+use crate::asm;
+
 /// Status Register
 #[derive(Clone, Copy, Debug)]
 pub struct Sr {
@@ -77,11 +79,7 @@ impl Sr {
 pub fn read() -> Sr {
     let r: u16;
     unsafe {
-        llvm_asm!("mov R2, $0"
-             : "=r"(r)
-             :
-             :
-             : "volatile");
+        asm!("mov R2, {0}", out(reg) r);
     }
     Sr { bits: r }
 }