Arm!

arch/arm/src/start.rs

@@ -0,0 +1,27 @@
+const SERIAL_BASE: *mut u8 = 0x16000000 as *mut u8;
+const SERIAL_FLAG_REGISTER: *const u8 = 0x16000018 as *const u8;
+const SERIAL_BUFFER_FULL: u8 =  (1 << 5);
+
+unsafe fn putc (c: u8)
+{
+    /* Wait until the serial buffer is empty */
+    while *SERIAL_FLAG_REGISTER & SERIAL_BUFFER_FULL == SERIAL_BUFFER_FULL {}
+
+    /* Put our character, c, into the serial buffer */
+    *SERIAL_BASE = c;
+}
+
+unsafe fn puts(string: &str)
+{
+    for b in string.bytes() {
+        putc(b);
+    }
+}
+
+#[no_mangle]
+#[naked]
+pub unsafe extern fn kstart() -> ! {
+    asm!("mov sp, 0x18000" : : : : "volatile");
+    puts("TEST\r\n");
+    loop {}
+}