refactor: unsafe only in adapter + libkos; forbid(unsafe_code) everywhere else; libkos Window (volatile, bounds-checked MMIO/DMA/shared mem), entry!, thread::spawn; MapRegion returns pages; kernel const-built (with_cores/install_platform); newtype addrs

crates/apps/echo/src/main.rs

@@ -1,4 +1,5 @@
 #![no_std]
+#![forbid(unsafe_code)]
 #![no_main]
 
 extern crate libkos;
@@ -6,8 +7,9 @@ extern crate libkos;
 use types::bounded::CapSlot;
 use libkos::syscall;
 
-#[unsafe(no_mangle)]
-extern "C" fn main() {
+libkos::entry!(main);
+
+fn main() {
     let ep = CapSlot::const_new(0);
 
     if let Ok(syscall::Received::Call { words: [w0, w1, w2, w3], .. }) = syscall::receive_msg(ep) {