From 539c6d00fffabaf7c3f61f2f8c1aaefa661fa500 Mon Sep 17 00:00:00 2001
From: Adam Greig <adam@adamgreig.com>
Date: Sun, 15 Mar 2020 19:40:37 +0000
Subject: Add UDF instruction. Closes #199.

---
 src/asm.rs | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

(limited to 'src')

diff --git a/src/asm.rs b/src/asm.rs
index 7b1a9ce..593aeac 100644
--- a/src/asm.rs
+++ b/src/asm.rs
@@ -81,6 +81,30 @@ pub fn nop() {
     }
 }
 
+
+/// Generate an Undefined Instruction exception.
+///
+/// Can be used as a stable alternative to `core::intrinsics::abort`.
+#[inline]
+pub fn udf() {
+    match () {
+        #[cfg(all(cortex_m, feature = "inline-asm"))]
+        () => unsafe { asm!("udf" :::: "volatile") },
+
+        #[cfg(all(cortex_m, not(feature = "inline-asm")))]
+        () => unsafe {
+            extern "C" {
+                fn __udf();
+            }
+
+            __udf()
+        },
+
+        #[cfg(not(cortex_m))]
+        () => unimplemented!(),
+    }
+}
+
 /// Wait For Event
 #[inline]
 pub fn wfe() {
-- 
cgit v1.2.3


From e3d7092189b76ff31edc24b43e6d2a75c84b6358 Mon Sep 17 00:00:00 2001
From: Adam Greig <adam@adamgreig.com>
Date: Sun, 15 Mar 2020 19:58:19 +0000
Subject: Mark asm::udf as divergent

---
 src/asm.rs | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

(limited to 'src')

diff --git a/src/asm.rs b/src/asm.rs
index 593aeac..3fe6393 100644
--- a/src/asm.rs
+++ b/src/asm.rs
@@ -86,10 +86,13 @@ pub fn nop() {
 ///
 /// Can be used as a stable alternative to `core::intrinsics::abort`.
 #[inline]
-pub fn udf() {
+pub fn udf() -> ! {
     match () {
         #[cfg(all(cortex_m, feature = "inline-asm"))]
-        () => unsafe { asm!("udf" :::: "volatile") },
+        () => unsafe {
+            asm!("udf" :::: "volatile");
+            loop { continue }
+        },
 
         #[cfg(all(cortex_m, not(feature = "inline-asm")))]
         () => unsafe {
@@ -97,7 +100,9 @@ pub fn udf() {
                 fn __udf();
             }
 
-            __udf()
+            __udf();
+
+            loop { continue }
         },
 
         #[cfg(not(cortex_m))]
-- 
cgit v1.2.3


From 715e59506e3a4482500f252270b42f12e2498849 Mon Sep 17 00:00:00 2001
From: Adam Greig <adam@adamgreig.com>
Date: Sun, 15 Mar 2020 23:29:28 +0000
Subject: Swap infinite loops for unreachable_unchecked()

---
 asm.s                           |   1 -
 bin/thumbv6m-none-eabi.a        | Bin 3074 -> 3070 bytes
 bin/thumbv7em-none-eabi.a       | Bin 5302 -> 5298 bytes
 bin/thumbv7em-none-eabihf.a     | Bin 5302 -> 5298 bytes
 bin/thumbv7m-none-eabi.a        | Bin 4244 -> 4240 bytes
 bin/thumbv8m.base-none-eabi.a   | Bin 4174 -> 4170 bytes
 bin/thumbv8m.main-none-eabi.a   | Bin 6584 -> 6580 bytes
 bin/thumbv8m.main-none-eabihf.a | Bin 6584 -> 6580 bytes
 src/asm.rs                      |   4 ++--
 9 files changed, 2 insertions(+), 3 deletions(-)

(limited to 'src')

diff --git a/asm.s b/asm.s
index 975e1ce..ed1ec3f 100644
--- a/asm.s
+++ b/asm.s
@@ -120,7 +120,6 @@ __sev:
   .thumb_func
 __udf:
   udf
-  bx lr
 
   .section .text.__wfe
   .global __wfe
diff --git a/bin/thumbv6m-none-eabi.a b/bin/thumbv6m-none-eabi.a
index 92076d7..06a7cb7 100644
Binary files a/bin/thumbv6m-none-eabi.a and b/bin/thumbv6m-none-eabi.a differ
diff --git a/bin/thumbv7em-none-eabi.a b/bin/thumbv7em-none-eabi.a
index a33db85..48da24d 100644
Binary files a/bin/thumbv7em-none-eabi.a and b/bin/thumbv7em-none-eabi.a differ
diff --git a/bin/thumbv7em-none-eabihf.a b/bin/thumbv7em-none-eabihf.a
index a33db85..48da24d 100644
Binary files a/bin/thumbv7em-none-eabihf.a and b/bin/thumbv7em-none-eabihf.a differ
diff --git a/bin/thumbv7m-none-eabi.a b/bin/thumbv7m-none-eabi.a
index 5949e33..296f66f 100644
Binary files a/bin/thumbv7m-none-eabi.a and b/bin/thumbv7m-none-eabi.a differ
diff --git a/bin/thumbv8m.base-none-eabi.a b/bin/thumbv8m.base-none-eabi.a
index 460e342..026250b 100644
Binary files a/bin/thumbv8m.base-none-eabi.a and b/bin/thumbv8m.base-none-eabi.a differ
diff --git a/bin/thumbv8m.main-none-eabi.a b/bin/thumbv8m.main-none-eabi.a
index 53c510f..6848518 100644
Binary files a/bin/thumbv8m.main-none-eabi.a and b/bin/thumbv8m.main-none-eabi.a differ
diff --git a/bin/thumbv8m.main-none-eabihf.a b/bin/thumbv8m.main-none-eabihf.a
index 53c510f..6848518 100644
Binary files a/bin/thumbv8m.main-none-eabihf.a and b/bin/thumbv8m.main-none-eabihf.a differ
diff --git a/src/asm.rs b/src/asm.rs
index 3fe6393..03b649f 100644
--- a/src/asm.rs
+++ b/src/asm.rs
@@ -91,7 +91,7 @@ pub fn udf() -> ! {
         #[cfg(all(cortex_m, feature = "inline-asm"))]
         () => unsafe {
             asm!("udf" :::: "volatile");
-            loop { continue }
+            core::hint::unreachable_unchecked();
         },
 
         #[cfg(all(cortex_m, not(feature = "inline-asm")))]
@@ -102,7 +102,7 @@ pub fn udf() -> ! {
 
             __udf();
 
-            loop { continue }
+            core::hint::unreachable_unchecked();
         },
 
         #[cfg(not(cortex_m))]
-- 
cgit v1.2.3