use hprint macros

examples/allocator.rs

@@ -17,13 +17,12 @@
 extern crate panic_halt;
 
 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 +38,7 @@ fn main() -> ! {
     // Growable array allocated on the heap
     let xs = vec![0, 1, 2];
 
-    let mut stdout = hio::hstdout().unwrap();
+    hprintln!("{:?}", xs).unwrap();
-    writeln!(stdout, "{:?}", xs).unwrap();
 
     loop {}
 }

examples/device.rs

@@ -27,11 +27,9 @@
 #[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]
@@ -58,14 +56,8 @@ fn main() -> ! {
 }
 
 // try commenting out this line: you'll end in `default_handler` instead of in `exti0`
-interrupt!(EXTI0, exti0, state: Option<HStdout> = None);
+interrupt!(EXTI0, exti0);
 
-fn exti0(state: &mut Option<HStdout>) {
+fn exti0() {
-    if state.is_none() {
+    hprint!(".").unwrap();
-        *state = Some(hio::hstdout().unwrap());
-    }
-
-    if let Some(hstdout) = state.as_mut() {
-        hstdout.write_str(".").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;
+    hprint!(".").unwrap();
-
-    if STDOUT.is_none() {
-        *STDOUT = Some(hio::hstdout().unwrap());
-    }
-
-    if let Some(hstdout) = STDOUT.as_mut() {
-        hstdout.write_str(".").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();
+    hprintln!("Hello, world!").unwrap();
-    writeln!(stdout, "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 {}