Barebones rust example working in user space.

Requires manually copying the executable over to the image.

rust/lib/mammoth/src/lib.rs

@@ -0,0 +1,28 @@
+#![no_std]
+#![allow(non_upper_case_globals)]
+#![allow(non_camel_case_types)]
+#![allow(non_snake_case)]
+
+use core::ffi::c_void;
+use core::panic::PanicInfo;
+
+include!("bindings.rs");
+
+fn syscall<T>(id: u64, req: &T) -> u64 {
+    unsafe { SysCall1(id, req as *const T as *const c_void) }
+}
+
+#[panic_handler]
+fn panic(_info: &PanicInfo) -> ! {
+    let req = ZProcessExitReq { code: 1 };
+    syscall(kZionProcessExit, &req);
+    unreachable!()
+}
+
+pub fn debug(msg: &str) {
+    let req = ZDebugReq {
+        message: msg.as_ptr() as *const i8,
+        size: msg.len() as u64,
+    };
+    syscall(kZionDebug, &req);
+}