diff --git a/.github/workflows/build-20210727.yml b/.github/workflows/build-20210727.yml
index 350b4237..f8d912c3 100644
--- a/.github/workflows/build-20210727.yml
+++ b/.github/workflows/build-20210727.yml
@@ -69,7 +69,7 @@ jobs:
         with:
           command: build
           use-cross: true
-          args: -p zircon-loader --target aarch64-unknown-linux-gnu --workspace --exclude linux-syscall --exclude linux-loader --exclude zcore
+          args: --target aarch64-unknown-linux-gnu --workspace --exclude linux-syscall --exclude linux-loader --exclude zcore
 
   build-user:
     runs-on: ${{ matrix.os }}
diff --git a/kernel-hal/src/bare/arch/riscv/config.rs b/kernel-hal/src/bare/arch/riscv/config.rs
index 5ffba939..97b01a5e 100644
--- a/kernel-hal/src/bare/arch/riscv/config.rs
+++ b/kernel-hal/src/bare/arch/riscv/config.rs
@@ -1,4 +1,6 @@
-/// Configuration of HAL.
+//! Kernel configuration.
+
+/// Kernel configuration passed by kernel when calls [`crate::primary_init_early()`].
 #[derive(Debug)]
 pub struct KernelConfig {
     pub phys_mem_start: usize,
diff --git a/kernel-hal/src/bare/arch/riscv/context.rs b/kernel-hal/src/bare/arch/riscv/context.rs
index ca7ea1de..b55ddb7c 100644
--- a/kernel-hal/src/bare/arch/riscv/context.rs
+++ b/kernel-hal/src/bare/arch/riscv/context.rs
@@ -1,3 +1,5 @@
+//! Context switch.
+
 use riscv::register::scause::{Exception, Trap};
 use riscv::register::{scause, stval};
 
diff --git a/kernel-hal/src/bare/arch/riscv/cpu.rs b/kernel-hal/src/bare/arch/riscv/cpu.rs
index 4fa884fb..ae28d564 100644
--- a/kernel-hal/src/bare/arch/riscv/cpu.rs
+++ b/kernel-hal/src/bare/arch/riscv/cpu.rs
@@ -1,3 +1,5 @@
+//! CPU information.
+
 hal_fn_impl! {
     impl mod crate::hal_fn::cpu {
         fn cpu_frequency() -> u16 {
diff --git a/kernel-hal/src/bare/arch/riscv/interrupt.rs b/kernel-hal/src/bare/arch/riscv/interrupt.rs
index 36bcd55f..0ebd72b2 100644
--- a/kernel-hal/src/bare/arch/riscv/interrupt.rs
+++ b/kernel-hal/src/bare/arch/riscv/interrupt.rs
@@ -1,3 +1,5 @@
+//! Interrupts management.
+
 use riscv::{asm, register::sstatus};
 
 hal_fn_impl! {
diff --git a/kernel-hal/src/bare/arch/riscv/vm.rs b/kernel-hal/src/bare/arch/riscv/vm.rs
index 49e899db..2ec1951c 100644
--- a/kernel-hal/src/bare/arch/riscv/vm.rs
+++ b/kernel-hal/src/bare/arch/riscv/vm.rs
@@ -1,3 +1,5 @@
+//! Virutal memory operations.
+
 use core::fmt::{Debug, Formatter, Result};
 use core::slice;
 
@@ -124,7 +126,7 @@ hal_fn_impl! {
 
 bitflags::bitflags! {
     /// Possible flags for a page table entry.
-    pub struct PTF: usize {
+    struct PTF: usize {
         const VALID =       1 << 0;
         const READABLE =    1 << 1;
         const WRITABLE =    1 << 2;
@@ -181,6 +183,7 @@ impl From<PTF> for MMUFlags {
 
 const PHYS_ADDR_MASK: u64 = 0x003f_ffff_ffff_fc00; // 10..54
 
+/// Sv39 and Sv48 page table entry.
 #[derive(Clone, Copy)]
 #[repr(transparent)]
 pub struct Rv64PTE(u64);
@@ -228,5 +231,5 @@ impl Debug for Rv64PTE {
     }
 }
 
-/// Sv39: Page-Based 39-bit Virtual-Memory System
+/// Sv39: Page-Based 39-bit Virtual-Memory System.
 pub type PageTable = PageTableImpl<PageTableLevel3, Rv64PTE>;
diff --git a/kernel-hal/src/bare/arch/x86_64/config.rs b/kernel-hal/src/bare/arch/x86_64/config.rs
index 2334742b..4a25cacd 100644
--- a/kernel-hal/src/bare/arch/x86_64/config.rs
+++ b/kernel-hal/src/bare/arch/x86_64/config.rs
@@ -1,7 +1,9 @@
+//! Kernel configuration.
+
 use uefi::proto::console::gop::ModeInfo;
 use uefi::table::boot::MemoryDescriptor;
 
-/// Configuration of HAL.
+/// Kernel configuration passed by kernel when calls [`crate::primary_init_early()`].
 #[derive(Debug)]
 pub struct KernelConfig {
     pub cmdline: &'static str,
diff --git a/kernel-hal/src/bare/arch/x86_64/context.rs b/kernel-hal/src/bare/arch/x86_64/context.rs
index 36562c3a..b82d0d47 100644
--- a/kernel-hal/src/bare/arch/x86_64/context.rs
+++ b/kernel-hal/src/bare/arch/x86_64/context.rs
@@ -1,3 +1,5 @@
+//! Context switch.
+
 use bitflags::bitflags;
 use x86_64::registers::control::Cr2;
 
diff --git a/kernel-hal/src/bare/arch/x86_64/cpu.rs b/kernel-hal/src/bare/arch/x86_64/cpu.rs
index 4d0de6d3..ec2ec826 100644
--- a/kernel-hal/src/bare/arch/x86_64/cpu.rs
+++ b/kernel-hal/src/bare/arch/x86_64/cpu.rs
@@ -1,3 +1,5 @@
+//! CPU information.
+
 use raw_cpuid::CpuId;
 
 lazy_static! {
diff --git a/kernel-hal/src/bare/arch/x86_64/interrupt.rs b/kernel-hal/src/bare/arch/x86_64/interrupt.rs
index 2deae307..fe3f0e03 100644
--- a/kernel-hal/src/bare/arch/x86_64/interrupt.rs
+++ b/kernel-hal/src/bare/arch/x86_64/interrupt.rs
@@ -1,3 +1,5 @@
+//! Interrupts management.
+
 use core::ops::Range;
 
 use crate::drivers::all_irq;
diff --git a/kernel-hal/src/bare/arch/x86_64/special.rs b/kernel-hal/src/bare/arch/x86_64/special.rs
index 08f83e82..7419e10d 100644
--- a/kernel-hal/src/bare/arch/x86_64/special.rs
+++ b/kernel-hal/src/bare/arch/x86_64/special.rs
@@ -1,3 +1,5 @@
+//! Functions only available on x86 platforms.
+
 use x86_64::instructions::port::Port;
 
 /// IO Port in instruction
diff --git a/kernel-hal/src/bare/arch/x86_64/vm.rs b/kernel-hal/src/bare/arch/x86_64/vm.rs
index 50fc2d79..ca955cac 100644
--- a/kernel-hal/src/bare/arch/x86_64/vm.rs
+++ b/kernel-hal/src/bare/arch/x86_64/vm.rs
@@ -1,3 +1,5 @@
+//! Virutal memory operations.
+
 use core::fmt::{Debug, Formatter, Result};
 use core::{convert::TryFrom, slice};
 
@@ -105,6 +107,7 @@ impl From<PTF> for MMUFlags {
 
 const PHYS_ADDR_MASK: u64 = 0x000f_ffff_ffff_f000; // 12..52
 
+/// Page table entry on x86.
 #[derive(Clone, Copy)]
 #[repr(transparent)]
 pub struct X86PTE(u64);
@@ -155,4 +158,5 @@ impl Debug for X86PTE {
     }
 }
 
+/// The 4-level page table on x86.
 pub type PageTable = PageTableImpl<PageTableLevel4, X86PTE>;
diff --git a/kernel-hal/src/bare/boot.rs b/kernel-hal/src/bare/boot.rs
index e24413e0..b28aac8c 100644
--- a/kernel-hal/src/bare/boot.rs
+++ b/kernel-hal/src/bare/boot.rs
@@ -1,3 +1,5 @@
+//! Bootstrap and initialization.
+
 use crate::{KernelConfig, KernelHandler, KCONFIG, KHANDLER};
 
 hal_fn_impl! {
diff --git a/kernel-hal/src/bare/mem.rs b/kernel-hal/src/bare/mem.rs
index 435aae48..23966ca4 100644
--- a/kernel-hal/src/bare/mem.rs
+++ b/kernel-hal/src/bare/mem.rs
@@ -1,3 +1,5 @@
+//! Physical memory operations.
+
 use alloc::vec::Vec;
 use core::ops::Range;
 
diff --git a/kernel-hal/src/bare/thread.rs b/kernel-hal/src/bare/thread.rs
index 6645be61..359b7df9 100644
--- a/kernel-hal/src/bare/thread.rs
+++ b/kernel-hal/src/bare/thread.rs
@@ -1,3 +1,5 @@
+//! Thread spawning.
+
 use alloc::boxed::Box;
 use core::task::{Context, Poll};
 use core::{future::Future, pin::Pin};
diff --git a/kernel-hal/src/bare/timer.rs b/kernel-hal/src/bare/timer.rs
index c427312d..0598d478 100644
--- a/kernel-hal/src/bare/timer.rs
+++ b/kernel-hal/src/bare/timer.rs
@@ -1,3 +1,5 @@
+//! Time and clock functions.
+
 use alloc::boxed::Box;
 use core::time::Duration;
 
diff --git a/kernel-hal/src/common/addr.rs b/kernel-hal/src/common/addr.rs
index a45fd96b..971bf0d7 100644
--- a/kernel-hal/src/common/addr.rs
+++ b/kernel-hal/src/common/addr.rs
@@ -2,8 +2,13 @@
 
 use crate::PAGE_SIZE;
 
+/// Physical address.
 pub type PhysAddr = usize;
+
+/// Virtual address.
 pub type VirtAddr = usize;
+
+/// Device address.
 pub type DevVAddr = usize;
 
 pub const fn align_down(addr: usize) -> usize {
diff --git a/kernel-hal/src/common/console.rs b/kernel-hal/src/common/console.rs
index e5126366..38724ce7 100644
--- a/kernel-hal/src/common/console.rs
+++ b/kernel-hal/src/common/console.rs
@@ -1,3 +1,5 @@
+//! Console input and output.
+
 use crate::drivers;
 use core::fmt::{Arguments, Result, Write};
 use spin::Mutex;
@@ -41,17 +43,26 @@ cfg_if! {
     }
 }
 
-/// Print format string and its arguments to serial.
+/// Writes a string slice into the serial.
+pub fn serial_write_str(s: &str) {
+    SERIAL_WRITER.lock().write_str(s).unwrap();
+}
+
+/// Writes formatted data into the serial.
 pub fn serial_write_fmt(fmt: Arguments) {
     SERIAL_WRITER.lock().write_fmt(fmt).unwrap();
 }
 
-/// Print format string and its arguments to serial.
-pub fn serial_write(s: &str) {
-    SERIAL_WRITER.lock().write_str(s).unwrap();
+/// Writes a string slice into the graphic console.
+#[allow(unused_variables)]
+pub fn graphic_console_write_str(s: &str) {
+    #[cfg(feature = "graphic")]
+    if let Some(cons) = GRAPHIC_CONSOLE.try_get() {
+        cons.lock().write_str(s).unwrap();
+    }
 }
 
-/// Print format string and its arguments to graphic console.
+/// Writes formatted data into the graphic console.
 #[allow(unused_variables)]
 pub fn graphic_console_write_fmt(fmt: Arguments) {
     #[cfg(feature = "graphic")]
@@ -60,32 +71,24 @@ pub fn graphic_console_write_fmt(fmt: Arguments) {
     }
 }
 
-/// Print format string and its arguments to graphic console.
-#[allow(unused_variables)]
-pub fn graphic_console_write(s: &str) {
-    #[cfg(feature = "graphic")]
-    if let Some(cons) = GRAPHIC_CONSOLE.try_get() {
-        cons.lock().write_str(s).unwrap();
-    }
+/// Writes a string slice into the serial, and the graphic console if it exists.
+pub fn console_write_str(s: &str) {
+    serial_write_str(s);
+    graphic_console_write_str(s);
 }
 
-/// Print format string and its arguments to serial and graphic console (if exists).
+/// Writes formatted data into the serial, and the graphic console if it exists.
 pub fn console_write_fmt(fmt: Arguments) {
     serial_write_fmt(fmt);
     graphic_console_write_fmt(fmt);
 }
 
-/// Print a string to serial and graphic console (if exists).
-pub fn console_write(s: &str) {
-    serial_write(s);
-    graphic_console_write(s);
-}
-
 /// Read buffer data from console (serial).
 pub async fn console_read(buf: &mut [u8]) -> usize {
     super::future::SerialReadFuture::new(buf).await
 }
 
+/// The POSIX `winsize` structure.
 #[repr(C)]
 #[derive(Clone, Copy, Default)]
 pub struct ConsoleWinSize {
diff --git a/kernel-hal/src/common/defs.rs b/kernel-hal/src/common/defs.rs
index 2ac1de66..52191330 100644
--- a/kernel-hal/src/common/defs.rs
+++ b/kernel-hal/src/common/defs.rs
@@ -10,6 +10,7 @@ pub struct HalError;
 pub type HalResult<T = ()> = core::result::Result<T, HalError>;
 
 bitflags! {
+    /// Generic memory flags.
     pub struct MMUFlags: usize {
         #[allow(clippy::identity_op)]
         const CACHE_1   = 1 << 0;
@@ -25,6 +26,7 @@ bitflags! {
 numeric_enum! {
     #[repr(u32)]
     #[derive(Debug, PartialEq, Clone, Copy)]
+    /// Generic cache policy.
     pub enum CachePolicy {
         Cached = 0,
         Uncached = 1,
@@ -32,8 +34,8 @@ numeric_enum! {
         WriteCombining = 3,
     }
 }
-pub const CACHE_POLICY_MASK: u32 = 3;
 
+/// The smallest size of a page (4K).
 pub const PAGE_SIZE: usize = super::vm::PageSize::Size4K as usize;
 
 pub use super::addr::{DevVAddr, PhysAddr, VirtAddr};
diff --git a/kernel-hal/src/common/mem.rs b/kernel-hal/src/common/mem.rs
index ef2abe0f..d5bbbf83 100644
--- a/kernel-hal/src/common/mem.rs
+++ b/kernel-hal/src/common/mem.rs
@@ -2,6 +2,7 @@ use alloc::vec::Vec;
 
 use crate::{PhysAddr, KHANDLER, PAGE_SIZE};
 
+/// A 4K size physical frame.
 #[derive(Debug)]
 pub struct PhysFrame {
     paddr: PhysAddr,
diff --git a/kernel-hal/src/common/user.rs b/kernel-hal/src/common/user.rs
index 7df1d92f..a4be3cd5 100644
--- a/kernel-hal/src/common/user.rs
+++ b/kernel-hal/src/common/user.rs
@@ -1,3 +1,5 @@
+//! Read/write user space pointer.
+
 use alloc::string::String;
 use alloc::vec::Vec;
 use core::fmt::{Debug, Formatter};
diff --git a/kernel-hal/src/common/vm.rs b/kernel-hal/src/common/vm.rs
index e997a566..fb08c6ee 100644
--- a/kernel-hal/src/common/vm.rs
+++ b/kernel-hal/src/common/vm.rs
@@ -1,5 +1,6 @@
 use crate::{addr::is_aligned, MMUFlags, PhysAddr, VirtAddr};
 
+/// Errors may occur during address translation.
 #[derive(Debug)]
 pub enum PagingError {
     NoMemory,
@@ -7,9 +8,13 @@ pub enum PagingError {
     AlreadyMapped,
 }
 
+/// Address translation result.
 pub type PagingResult<T = ()> = Result<T, PagingError>;
 
+/// The [`PagingError::NotMapped`] can be ignored.
 pub trait IgnoreNotMappedErr {
+    /// If self is `Err(PagingError::NotMapped`, ignores the error and returns
+    /// `Ok(())`, otherwise remain unchanged.
     fn ignore(self) -> PagingResult;
 }
 
@@ -22,6 +27,7 @@ impl<T> IgnoreNotMappedErr for PagingResult<T> {
     }
 }
 
+/// Possible page size (4K, 2M, 1G).
 #[repr(usize)]
 #[derive(Debug, Copy, Clone, Eq, PartialEq)]
 pub enum PageSize {
@@ -30,6 +36,7 @@ pub enum PageSize {
     Size1G = 0x4000_0000,
 }
 
+/// A 4K, 2M or 1G size page.
 #[derive(Debug, Copy, Clone)]
 pub struct Page {
     pub vaddr: VirtAddr,
@@ -61,6 +68,7 @@ impl Page {
     }
 }
 
+/// A generic page table abstraction.
 pub trait GenericPageTable: Sync + Send {
     /// Get the physical address of root page table.
     fn table_phys(&self) -> PhysAddr;
diff --git a/kernel-hal/src/drivers.rs b/kernel-hal/src/drivers.rs
index 67278e54..922e7c6a 100644
--- a/kernel-hal/src/drivers.rs
+++ b/kernel-hal/src/drivers.rs
@@ -1,3 +1,5 @@
+//! Device drivers.
+
 use alloc::{sync::Arc, vec::Vec};
 use core::convert::From;
 
diff --git a/kernel-hal/src/hal_fn.rs b/kernel-hal/src/hal_fn.rs
index 41c6f2d8..94dce320 100644
--- a/kernel-hal/src/hal_fn.rs
+++ b/kernel-hal/src/hal_fn.rs
@@ -5,6 +5,7 @@ use crate::drivers::prelude::{IrqHandler, IrqPolarity, IrqTriggerMode};
 use crate::{common, HalResult, KernelConfig, KernelHandler, MMUFlags, PhysAddr, VirtAddr};
 
 hal_fn_def! {
+    /// Bootstrap and initialization.
     pub mod boot {
         /// The kernel command line.
         pub fn cmdline() -> String { "".into() }
@@ -27,6 +28,7 @@ hal_fn_def! {
         pub fn secondary_init() {}
     }
 
+    /// CPU information.
     pub mod cpu {
         /// Current CPU ID.
         pub fn cpu_id() -> u8 { 0 }
@@ -35,6 +37,7 @@ hal_fn_def! {
         pub fn cpu_frequency() -> u16 { 3000 }
     }
 
+    /// Physical memory operations.
     pub mod mem: common::mem {
         /// Convert physical address to virtual address.
         pub(crate) fn phys_to_virt(paddr: PhysAddr) -> VirtAddr;
@@ -58,6 +61,7 @@ hal_fn_def! {
         pub fn frame_flush(target: PhysAddr);
     }
 
+    /// Virutal memory operations.
     pub mod vm: common::vm {
         /// Read current VM token. (e.g. CR3, SATP, ...)
         pub fn current_vmtoken() -> PhysAddr;
@@ -72,6 +76,7 @@ hal_fn_def! {
         pub(crate) fn pt_clone_kernel_space(dst_pt_root: PhysAddr, src_pt_root: PhysAddr);
     }
 
+    /// Interrupts management.
     pub mod interrupt {
         /// Suspend the CPU (also enable interrupts) and wait for an interrupt
         /// to occurs, then disable interrupts.
@@ -119,6 +124,7 @@ hal_fn_def! {
         pub(crate) fn console_write_early(_s: &str) {}
     }
 
+    /// Context switch.
     pub mod context: common::context {
         /// Enter user mode.
         pub fn context_run(context: &mut UserContext) {
@@ -139,6 +145,7 @@ hal_fn_def! {
         pub fn fetch_page_fault_info(info_reg: usize) -> (VirtAddr, MMUFlags);
     }
 
+    /// Thread spawning.
     pub mod thread: common::thread {
         /// Spawn a new thread.
         pub fn spawn(future: Pin<Box<dyn Future<Output = ()> + Send + 'static>>, vmtoken: usize);
@@ -146,10 +153,11 @@ hal_fn_def! {
         /// Set tid and pid of current task.
         pub fn set_tid(tid: u64, pid: u64);
 
-        /// Get tid and pid of current task.]
+        /// Get tid and pid of current task.
         pub fn get_tid() -> (u64, u64);
     }
 
+    /// Time and clock functions.
     pub mod timer {
         /// Get current time.
         /// TODO: use `Instant` as return type.
@@ -168,6 +176,7 @@ hal_fn_def! {
         pub(crate) fn timer_tick();
     }
 
+    /// Random number generator.
     pub mod rand {
         /// Fill random bytes to the buffer
         #[allow(unused_variables)]
@@ -194,6 +203,7 @@ hal_fn_def! {
         }
     }
 
+    /// VDSO constants.
     pub mod vdso: common::vdso {
         /// Get platform specific information.
         pub fn vdso_constants() -> VdsoConstants {
diff --git a/kernel-hal/src/kernel_handler.rs b/kernel-hal/src/kernel_handler.rs
index a369047e..9d703d8d 100644
--- a/kernel-hal/src/kernel_handler.rs
+++ b/kernel-hal/src/kernel_handler.rs
@@ -2,6 +2,7 @@
 
 use crate::{utils::init_once::InitOnce, MMUFlags, PhysAddr, VirtAddr};
 
+/// Functions implemented in the kernel and used by HAL funtions.
 pub trait KernelHandler: Send + Sync + 'static {
     /// Allocate one physical frame.
     fn frame_alloc(&self) -> Option<PhysAddr> {
diff --git a/kernel-hal/src/libos/boot.rs b/kernel-hal/src/libos/boot.rs
index ee22e719..7e1c2deb 100644
--- a/kernel-hal/src/libos/boot.rs
+++ b/kernel-hal/src/libos/boot.rs
@@ -1,3 +1,5 @@
+//! Bootstrap and initialization.
+
 use crate::{KernelConfig, KernelHandler, KCONFIG, KHANDLER};
 
 hal_fn_impl! {
diff --git a/kernel-hal/src/libos/config.rs b/kernel-hal/src/libos/config.rs
index 50aa1840..30efd283 100644
--- a/kernel-hal/src/libos/config.rs
+++ b/kernel-hal/src/libos/config.rs
@@ -1,3 +1,5 @@
-/// Configuration of HAL.
+//! Kernel configuration.
+
+/// Kernel configuration passed by kernel when calls [`crate::primary_init_early()`].
 #[derive(Debug)]
 pub struct KernelConfig;
diff --git a/kernel-hal/src/libos/mem.rs b/kernel-hal/src/libos/mem.rs
index c8f6db6d..62642d25 100644
--- a/kernel-hal/src/libos/mem.rs
+++ b/kernel-hal/src/libos/mem.rs
@@ -1,3 +1,5 @@
+//! Physical memory operations.
+
 use alloc::vec::Vec;
 use core::ops::Range;
 
diff --git a/kernel-hal/src/libos/special.rs b/kernel-hal/src/libos/special.rs
index 6caef2ad..21f31095 100644
--- a/kernel-hal/src/libos/special.rs
+++ b/kernel-hal/src/libos/special.rs
@@ -1,3 +1,5 @@
+//! Functions only available on the libos mode.
+
 #[cfg(feature = "graphic")]
 pub fn run_graphic_service() {
     use crate::drivers::{all_display, all_input};
diff --git a/kernel-hal/src/libos/thread.rs b/kernel-hal/src/libos/thread.rs
index 4567ea9d..46a4c23d 100644
--- a/kernel-hal/src/libos/thread.rs
+++ b/kernel-hal/src/libos/thread.rs
@@ -1,3 +1,5 @@
+//! Thread spawning.
+
 use async_std::task_local;
 use core::{cell::Cell, future::Future, pin::Pin};
 
diff --git a/kernel-hal/src/libos/timer.rs b/kernel-hal/src/libos/timer.rs
index 12d5d23a..1e438081 100644
--- a/kernel-hal/src/libos/timer.rs
+++ b/kernel-hal/src/libos/timer.rs
@@ -1,3 +1,5 @@
+//! Time and clock functions.
+
 use async_std::task;
 use std::time::{Duration, SystemTime};
 
diff --git a/kernel-hal/src/libos/vdso.rs b/kernel-hal/src/libos/vdso.rs
index 43875032..c8f8a072 100644
--- a/kernel-hal/src/libos/vdso.rs
+++ b/kernel-hal/src/libos/vdso.rs
@@ -1,3 +1,5 @@
+//! VDSO constants.
+
 hal_fn_impl! {
     impl mod crate::hal_fn::vdso {
         fn vdso_constants() -> VdsoConstants {
diff --git a/kernel-hal/src/libos/vm.rs b/kernel-hal/src/libos/vm.rs
index eb05cb0b..1b207440 100644
--- a/kernel-hal/src/libos/vm.rs
+++ b/kernel-hal/src/libos/vm.rs
@@ -1,3 +1,5 @@
+//! Virutal memory operations.
+
 use super::mem::{MOCK_PHYS_MEM, PMEM_MAP_VADDR, PMEM_SIZE};
 use crate::{addr::is_aligned, MMUFlags, PhysAddr, VirtAddr, PAGE_SIZE};
 
@@ -9,7 +11,7 @@ hal_fn_impl! {
     }
 }
 
-/// Page Table
+/// Dummy page table implemented by `mmap`, `munmap`, and `mprotect`.
 pub struct PageTable;
 
 impl PageTable {
diff --git a/kernel-hal/src/macros.rs b/kernel-hal/src/macros.rs
index 13ef3d16..0bdfe567 100644
--- a/kernel-hal/src/macros.rs
+++ b/kernel-hal/src/macros.rs
@@ -1,12 +1,14 @@
 macro_rules! hal_fn_def {
     (
         $(
+            $(#[$inner:ident $($args:tt)*])*
             $vis:vis mod $mod_name:ident $( : $base:path )? {
                 $($fn:tt)*
             }
         )+
     ) => {
         $(
+            $(#[$inner $($args)*])*
             $vis mod $mod_name {
                 #![allow(unused_imports)]
                 $( pub use $base::*; )?
diff --git a/linux-object/src/fs/stdio.rs b/linux-object/src/fs/stdio.rs
index 3abc8241..d50362b7 100644
--- a/linux-object/src/fs/stdio.rs
+++ b/linux-object/src/fs/stdio.rs
@@ -152,7 +152,7 @@ impl INode for Stdout {
     fn write_at(&self, _offset: usize, buf: &[u8]) -> Result<usize> {
         // we do not care the utf-8 things, we just want to print it!
         let s = unsafe { core::str::from_utf8_unchecked(buf) };
-        kernel_hal::console::console_write(s);
+        kernel_hal::console::console_write_str(s);
         Ok(buf.len())
     }
     fn poll(&self) -> Result<PollStatus> {
diff --git a/zircon-syscall/src/debug.rs b/zircon-syscall/src/debug.rs
index 1f5b866d..1f2859f1 100644
--- a/zircon-syscall/src/debug.rs
+++ b/zircon-syscall/src/debug.rs
@@ -6,7 +6,7 @@ impl Syscall<'_> {
     pub fn sys_debug_write(&self, buf: UserInPtr<u8>, len: usize) -> ZxResult {
         info!("debug.write: buf=({:?}; {:#x})", buf, len);
         let data = buf.read_array(len)?;
-        kernel_hal::console::console_write(core::str::from_utf8(&data).unwrap());
+        kernel_hal::console::console_write_str(core::str::from_utf8(&data).unwrap());
         Ok(())
     }
 
diff --git a/zircon-syscall/src/debuglog.rs b/zircon-syscall/src/debuglog.rs
index 5583a889..59cfa9e5 100644
--- a/zircon-syscall/src/debuglog.rs
+++ b/zircon-syscall/src/debuglog.rs
@@ -54,9 +54,9 @@ impl Syscall<'_> {
         let dlog = proc.get_object_with_rights::<DebugLog>(handle_value, Rights::WRITE)?;
         dlog.write(Severity::Info, options, self.thread.id(), proc.id(), &data);
         // print to kernel console
-        kernel_hal::console::console_write(&data);
+        kernel_hal::console::console_write_str(&data);
         if data.as_bytes().last() != Some(&b'\n') {
-            kernel_hal::console::console_write("\n");
+            kernel_hal::console::console_write_str("\n");
         }
         Ok(())
     }