[rust/ci/qemu] main for qemu run.

- taken from japaric/lm3s6965evb

1 files changed, 53 insertions, 0 deletions

diff --git a/cortex-m-rt/examples/qemu.rs b/cortex-m-rt/examples/qemu.rs
new file mode 100644
index 0000000..f3850d5
--- /dev/null
+++ b/cortex-m-rt/examples/qemu.rs
@@ -0,0 +1,53 @@
+#![feature(stdsimd)]
+#![no_main]
+#![no_std]
+
+extern crate cortex_m;
+
+#[macro_use(entry, exception)]
+extern crate cortex_m_rt as rt;
+extern crate cortex_m_semihosting as semihosting;
+extern crate panic_abort;
+extern crate unreachable;
+
+use core::arch::arm;
+use core::fmt::Write;
+use rt::ExceptionFrame;
+
+entry!(main);
+
+fn main() -> ! {
+    let x = 42;
+
+    loop {
+        unsafe { arm::__NOP() }
+
+        // write something through semihosting interface
+        let mut hstdout = semihosting::hio::hstdout().unwrap();
+        write!(hstdout, "x = {}\n", x);
+
+        // exit from qemu
+        semihosting::debug::exit(semihosting::debug::EXIT_SUCCESS);
+
+        // hint to the optimizer that any code path which calls this function is statically unreachable
+        unsafe {
+            unreachable::unreachable();
+        }
+    }
+}
+
+// define the hard fault handler
+exception!(HardFault, hard_fault);
+
+#[inline(always)]
+fn hard_fault(_ef: &ExceptionFrame) -> ! {
+    loop {
+        unsafe { arm::__NOP() }
+    }
+}
+
+// define the default exception handler
+exception!(*, default_handler);
+
+#[inline(always)]
+fn default_handler(_irqn: i16) {}