Bump cortex-m dev-dep to 0.6 (it's only a dev-dep and so doesn't affect other packages)

Disable the semihosting test on thumbv8, as it's currently unsupported in cortex-m-semihosting

Author: thejpster

cortex-m-rt/Cargo.toml

@@ -19,10 +19,21 @@ autoexamples = true
 r0 = "0.2.2"
 cortex-m-rt-macros = { path = "macros", version = "0.1.5" }
 
+[target.thumbv7em-none-eabihf.dev-dependencies]
+cortex-m-semihosting = "0.3.1"
+
+[target.thumbv7em-none-eabi.dev-dependencies]
+cortex-m-semihosting = "0.3.1"
+
+[target.thumbv7m-none-eabi.dev-dependencies]
+cortex-m-semihosting = "0.3.1"
+
+[target.thumbv6m-none-eabi.dev-dependencies]
+cortex-m-semihosting = "0.3.1"
+
 [dev-dependencies]
-cortex-m = ">= 0.5.7, <0.7"
+cortex-m = "0.6"
 panic-halt = "0.2.0"
-cortex-m-semihosting = "0.3.1"
 
 [dev-dependencies.rand]
 default-features = false

cortex-m-rt/examples/qemu.rs

@@ -2,28 +2,39 @@
 #![no_main]
 #![no_std]
 
-extern crate cortex_m;
 
+extern crate cortex_m;
 extern crate cortex_m_rt as rt;
+
+#[cfg(not(armv8m))]
 extern crate cortex_m_semihosting as semihosting;
+
 extern crate panic_halt;
 
-use core::fmt::Write;
 use cortex_m::asm;
 use rt::entry;
 
+#[cfg(not(armv8m))]
 #[entry]
 fn main() -> ! {
+    use core::fmt::Write;
     let x = 42;
 
     loop {
         asm::nop();
 
         // write something through semihosting interface
         let mut hstdout = semihosting::hio::hstdout().unwrap();
-        write!(hstdout, "x = {}\n", x);
-
+        write!(hstdout, "x = {}\n", x).unwrap();
         // exit from qemu
         semihosting::debug::exit(semihosting::debug::EXIT_SUCCESS);
     }
 }
+
+#[cfg(armv8m)]
+#[entry]
+fn main() -> ! {
+    loop {
+        asm::nop();
+    }
+}