Added backtrace limit to mitigate infinite backtraces

update interrupt usage

Cargo.toml

@@ -1,13 +1,14 @@
 [package]
 authors = ["{{authors}}"]
 edition = "2018"
+readme = "README.md"
 name = "{{project-name}}"
 version = "0.1.0"
 
 [dependencies]
-cortex-m = "0.5.7"
-cortex-m-rt = "0.6.3"
-cortex-m-semihosting = "0.3.1"
+cortex-m = "0.5.8"
+cortex-m-rt = "0.6.5"
+cortex-m-semihosting = "0.3.2"
 panic-halt = "0.2.0"
 
 # Uncomment for the panic example.

README.md

@@ -8,12 +8,9 @@ This project is developed and maintained by the [Cortex-M team][team].
 
 To build embedded programs using this template you'll need:
 
-- Rust 1.30, 1.30-beta, nightly-2018-09-13 or a newer toolchain. e.g. `rustup
+- Rust 1.31, 1.30-beta, nightly-2018-09-13 or a newer toolchain. e.g. `rustup
   default beta`
 
-> **NOTE**: 1.30-beta is not out yet so you'll have to use the nightly channel
-> in the meantime.
-
 - The `cargo generate` subcommand. [Installation
   instructions](https://github.com/ashleygwilliams/cargo-generate#installation).
 
@@ -128,5 +125,5 @@ Contribution to this crate is organized under the terms of the [Rust Code of
 Conduct][CoC], the maintainer of this crate, the [Cortex-M team][team], promises
 to intervene to uphold that code of conduct.
 
-[CoC]: CODE_OF_CONDUCT.md
+[CoC]: https://www.rust-lang.org/policies/code-of-conduct
 [team]: https://github.com/rust-embedded/wg#the-cortex-m-team

examples/allocator.rs

@@ -14,16 +14,16 @@
 #![no_main]
 #![no_std]
 
+extern crate alloc;
 extern crate panic_halt;
 
+use self::alloc::vec;
 use core::alloc::Layout;
-use core::fmt::Write;
 
-use alloc::vec;
 use alloc_cortex_m::CortexMHeap;
 use cortex_m::asm;
 use cortex_m_rt::entry;
-use cortex_m_semihosting::hio;
+use cortex_m_semihosting::hprintln;
 
 // this is the allocator the application will use
 #[global_allocator]
@@ -39,8 +39,11 @@ fn main() -> ! {
     // Growable array allocated on the heap
     let xs = vec![0, 1, 2];
 
-    let mut stdout = hio::hstdout().unwrap();
-    writeln!(stdout, "{:?}", xs).unwrap();
+    hprintln!("{:?}", xs).unwrap();
+
+    // exit QEMU
+    // NOTE do not run this on hardware; it can corrupt OpenOCD state
+    debug::exit(debug::EXIT_SUCCESS);
 
     loop {}
 }

examples/device.rs

@@ -5,9 +5,6 @@
 //!
 //! [`svd2rust`]: https://crates.io/crates/svd2rust
 //!
-//! Device crates also provide an `interrupt!` macro (behind the "rt" feature) to register interrupt
-//! handlers.
-//!
 //! This example depends on the [`stm32f103xx`] crate so you'll have to add it to your Cargo.toml.
 //!
 //! [`stm32f103xx`]: https://crates.io/crates/stm32f103xx
@@ -27,11 +24,9 @@
 #[allow(unused_extern_crates)]
 extern crate panic_halt;
 
-use core::fmt::Write;
-
 use cortex_m::peripheral::syst::SystClkSource;
 use cortex_m_rt::entry;
-use cortex_m_semihosting::hio::{self, HStdout};
+use cortex_m_semihosting::hprint;
 use stm32f30x::{interrupt, Interrupt};
 
 #[entry]
@@ -53,19 +48,11 @@ fn main() -> ! {
         while !syst.has_wrapped() {}
 
         // trigger the `EXTI0` interrupt
-        nvic.set_pending(Interrupt::EXTI0);
+        NVIC::pend(Interrupt::EXTI0);
     }
 }
 
-// try commenting out this line: you'll end in `default_handler` instead of in `exti0`
-interrupt!(EXTI0, exti0, state: Option<HStdout> = None);
-
-fn exti0(state: &mut Option<HStdout>) {
-    if state.is_none() {
-        *state = Some(hio::hstdout().unwrap());
-    }
-
-    if let Some(hstdout) = state.as_mut() {
-        hstdout.write_str(".").unwrap();
-    }
+#[interrupt]
+fn EXTI0() {
+    hprint!(".").unwrap();
 }

examples/exception.rs

@@ -12,12 +12,10 @@
 
 extern crate panic_halt;
 
-use core::fmt::Write;
-
 use cortex_m::peripheral::syst::SystClkSource;
 use cortex_m::Peripherals;
 use cortex_m_rt::{entry, exception};
-use cortex_m_semihosting::hio::{self, HStdout};
+use cortex_m_semihosting::hprint;
 
 #[entry]
 fn main() -> ! {
@@ -35,13 +33,5 @@ fn main() -> ! {
 
 #[exception]
 fn SysTick() {
-    static mut STDOUT: Option<HStdout> = None;
-
-    if STDOUT.is_none() {
-        *STDOUT = Some(hio::hstdout().unwrap());
-    }
-
-    if let Some(hstdout) = STDOUT.as_mut() {
-        hstdout.write_str(".").unwrap();
-    }
+    hprint!(".").unwrap();
 }

examples/hello.rs

@@ -5,17 +5,15 @@
 
 extern crate panic_halt;
 
-use core::fmt::Write;
-
 use cortex_m_rt::entry;
-use cortex_m_semihosting::{debug, hio};
+use cortex_m_semihosting::{debug, hprintln};
 
 #[entry]
 fn main() -> ! {
-    let mut stdout = hio::hstdout().unwrap();
-    writeln!(stdout, "Hello, world!").unwrap();
+    hprintln!("Hello, world!").unwrap();
 
-    // exit QEMU or the debugger section
+    // exit QEMU
+    // NOTE do not run this on hardware; it can corrupt OpenOCD state
     debug::exit(debug::EXIT_SUCCESS);
 
     loop {}

examples/test_on_host.rs

@@ -0,0 +1,57 @@
+//! Conditionally compiling tests with std and our executable with no_std.
+//!
+//! Rust's built in unit testing framework requires the standard library,
+//! but we need to build our final executable with no_std.
+//! The testing framework also generates a `main` method, so we need to only use the `#[entry]`
+//! annotation when building our final image.
+//! For more information on why this example works, see this excellent blog post.
+//! https://os.phil-opp.com/unit-testing/
+//!
+//! Running this example:
+//!
+//! Ensure there are no targets specified under `[build]` in `.cargo/config`
+//! In order to make this work, we lose the convenience of having a default target that isn't the
+//! host.
+//!
+//! cargo build --example test_on_host --target thumbv7m-none-eabi
+//! cargo test --example test_on_host
+
+#![cfg_attr(test, allow(unused_imports))]
+
+#![cfg_attr(not(test), no_std)]
+#![cfg_attr(not(test), no_main)]
+
+// pick a panicking behavior
+#[cfg(not(test))]
+extern crate panic_halt; // you can put a breakpoint on `rust_begin_unwind` to catch panics
+// extern crate panic_abort; // requires nightly
+// extern crate panic_itm; // logs messages over ITM; requires ITM support
+// extern crate panic_semihosting; // logs messages to the host stderr; requires a debugger
+
+use cortex_m::asm;
+use cortex_m_rt::entry;
+
+#[cfg(not(test))]
+#[entry]
+fn main() -> ! {
+    asm::nop(); // To not have main optimize to abort in release mode, remove when you add code
+
+    loop {
+        // your code goes here
+    }
+}
+
+fn add(a: i32, b: i32) -> i32 {
+    a + b
+}
+
+#[cfg(test)]
+mod test {
+  use super::*;
+
+  #[test]
+  fn foo() {
+    println!("tests work!");
+    assert!(2 == add(1,1));
+  }
+}

memory.x

@@ -19,3 +19,16 @@ MEMORY
 /* This is required only on microcontrollers that store some configuration right
    after the vector table */
 /* _stext = ORIGIN(FLASH) + 0x400; */
+
+/* Example of putting non-initialized variables into custom RAM locations. */
+/* This assumes you have defined a region RAM2 above, and in the Rust
+   sources added the attribute `#[link_section = ".ram2bss"]` to the data
+   you want to place there. */
+/* Note that the section will not be zero-initialized by the runtime! */
+/* SECTIONS {
+     .ram2bss (NOLOAD) : ALIGN(4) {
+       *(.ram2bss);
+       . = ALIGN(4);
+     } > RAM2
+   } INSERT AFTER .bss;
+*/

openocd.gdb

@@ -3,9 +3,12 @@ target extended-remote :3333
 # print demangled symbols
 set print asm-demangle on
 
+# set backtrace limit to not have infinite backtrace loops
+set backtrace limit 32
+
 # detect unhandled exceptions, hard faults and panics
 break DefaultHandler
-break UserHardFault
+break HardFault
 break rust_begin_unwind
 
 # *try* to stop at the user entry point (it might be gone due to inlining)

src/main.rs

@@ -7,10 +7,13 @@ extern crate panic_halt; // you can put a breakpoint on `rust_begin_unwind` to c
 // extern crate panic_itm; // logs messages over ITM; requires ITM support
 // extern crate panic_semihosting; // logs messages to the host stderr; requires a debugger
 
+use cortex_m::asm;
 use cortex_m_rt::entry;
 
 #[entry]
 fn main() -> ! {
+    asm::nop(); // To not have main optimize to abort in release mode, remove when you add code
+
     loop {
         // your code goes here
     }