Add host.test and update documents

Makefile

@@ -82,8 +82,8 @@ os:
 
 .PHONY : doc
 doc:
-	# `cargo doc -p os --open` to open os doc.
-	# `cargo doc -p noli --open` to open noli doc.
+	# `cargo doc -p os --open --document-private-items` to open os doc.
+	# `cargo doc -p noli --open --target x86_64-unknown-none --document-private-items` to open noli doc for WasabiOS apps.
 	cargo doc --all
 
 .PHONY : clippy

noli/src/sys/wasabi.rs

@@ -165,12 +165,10 @@ impl SystemApi for Api {
         if addr == 0 {
             None
         } else {
-            println!("addr = {addr:#X}");
             let addr = addr as *const u8;
             let mut size = [0u8; 8];
             size.copy_from_slice(unsafe { slice::from_raw_parts(addr, 8) });
             let size = usize::from_le_bytes(size);
-            println!("size = {size:#X}");
             Some(unsafe { slice::from_raw_parts(addr, size) })
         }
     }

os/src/main.rs

@@ -153,18 +153,23 @@ fn run_tasks() -> Result<()> {
         // Note: this message is used by e2e_test. Please do not remove.
         info!("console_task has started");
         let mut s = String::new();
+        print!("> ");
         loop {
             if let Some(c) = InputManager::take().pop_input() {
                 if c == '\r' || c == '\n' {
+                    println!();
                     if let Err(e) = cmd::run(&s).await {
                         error!("{e:?}");
                     };
                     s.clear();
+                    print!("> ");
                 }
                 match c {
                     '\x7f' | '\x08' => {
-                        print!("{0} {0}", 0x08 as char);
-                        s.pop();
+                        if !s.is_empty() {
+                            print!("{0} {0}", 0x08 as char);
+                            s.pop();
+                        }
                     }
                     '\n' => {
                         // Do nothing

os/src/memory.rs

@@ -3,7 +3,6 @@ extern crate alloc;
 use crate::allocator::ALLOCATOR;
 use crate::error::Error;
 use crate::error::Result;
-use crate::info;
 use crate::util::size_in_pages_from_bytes;
 use crate::util::PAGE_SIZE;
 use crate::x86_64::paging::with_current_page_table;
@@ -107,7 +106,6 @@ impl ContiguousPhysicalMemoryPages {
     }
     pub fn set_page_attr(&mut self, attr: PageAttr) -> Result<()> {
         let range = self.range();
-        info!("Setting page attr for {:?} to {:?}", range, attr);
         unsafe {
             with_current_page_table(|table| {
                 table

os/src/process.rs

@@ -3,7 +3,6 @@ extern crate alloc;
 use crate::error::Result;
 use crate::memory::ContiguousPhysicalMemoryPages;
 use crate::mutex::Mutex;
-use crate::println;
 use crate::x86_64::context::unchecked_load_context;
 use crate::x86_64::context::unchecked_switch_context;
 use crate::x86_64::context::ExecutionContext;
@@ -52,7 +51,6 @@ impl ProcessContext {
         let args_region = match args {
             Some(args) => {
                 let args = serialize_args(args);
-                println!("Serialized args: {args:?}");
                 let mut args_region = ContiguousPhysicalMemoryPages::alloc_bytes(args.len())?;
                 args_region.fill_with_bytes(0);
                 args_region.as_mut_slice()[0..args.len()].copy_from_slice(&args);
@@ -114,9 +112,7 @@ impl Scheduler {
     }
     pub fn exit_current_process(&self) -> ! {
         let to = {
-            crate::info!("lock the queue");
             let mut queue = self.queue.lock();
-            crate::info!("queue lock held");
             if queue.len() <= 1 {
                 // No process to switch
                 panic!("No more process to schedule!");
@@ -125,7 +121,6 @@ impl Scheduler {
                 .pop_front()
                 .expect("queue should have a process to exit");
             from.exited.store(true, Ordering::SeqCst);
-            crate::info!("getting to");
             let to = unsafe {
                 queue
                     .front_mut()
@@ -134,10 +129,8 @@ impl Scheduler {
                     .lock()
                     .as_mut_ptr()
             };
-            crate::info!("got to");
             to
         };
-        crate::info!("Loading next context");
         unsafe { unchecked_load_context(to) };
         unreachable!("Nothing should come back here");
     }

os/src/syscall.rs

@@ -81,8 +81,10 @@ fn sys_get_args_region(_args: &[u64; 5]) -> u64 {
     }
 }
 
+/// sys_nslookup provides DNS resolution for applications.
+/// As written in [RFC2606](https://datatracker.ietf.org/doc/html/rfc2606#section-2),
+/// this function handles some hard-coded hostnames for testing purpose.
 fn sys_nslookup(args: &[u64; 5]) -> i64 {
-    info!("sys_nslookup!");
     let host = {
         let host = args[0] as *const u8;
         let len = args[1] as usize;
@@ -98,6 +100,12 @@ fn sys_nslookup(args: &[u64; 5]) -> i64 {
     if host == "wasabitest.example.com" {
         result[0] = [127, 0, 0, 1];
         return 1;
+    } else if host == "host.test" {
+        // Host (=default gateway) in the QEMU user network.
+        // The host machine's exposed ports will be accessible via this address.
+        // It also responds to ICMP ping request.
+        result[0] = [10, 0, 2, 2];
+        return 1;
     } else if host == "wasabitest.example.invalid" {
         // c.f. https://www.rfc-editor.org/rfc/rfc6761.html
         // >  The domain "invalid." and any names falling within ".invalid." are special in the ways listed below.

os/src/x86_64/context.rs

@@ -162,7 +162,6 @@ pub unsafe fn unchecked_switch_context(from: *mut ExecutionContext, to: *mut Exe
 /// # Safety
 /// `to` should be a valid ExecutionContext, and both contexts should not be locked on the call.
 pub unsafe fn unchecked_load_context(to: *mut ExecutionContext) {
-    crate::info!("unchecked_load_context");
     asm_restore_context(to as *mut u8);
 }