diff --git a/kernel-hal-bare/src/arch/riscv/mod.rs b/kernel-hal-bare/src/arch/riscv/mod.rs
index 5b332639..98bee9ee 100644
--- a/kernel-hal-bare/src/arch/riscv/mod.rs
+++ b/kernel-hal-bare/src/arch/riscv/mod.rs
@@ -413,7 +413,7 @@ pub fn serial_read(buf: &mut [u8]) -> usize {
 }
 
 #[export_name = "hal_serial_write"]
-pub fn serial_write(s: &str) {
+pub fn print_str(s: &str) {
     //putfmt(format_args!("{}", s));
     putfmt_uart(format_args!("{}", s));
 }
@@ -631,8 +631,8 @@ pub fn init_framebuffer(width: u32, height: u32, addr: usize, size: usize) {
     *FRAME_BUFFER.write() = Some(fb_info);
 }
 
-#[export_name = "hal_mice_set_callback"]
-pub fn mice_set_callback(_callback: Box<dyn Fn([u8; 3]) + Send + Sync>) {
+#[export_name = "hal_mouse_set_callback"]
+pub fn mouse_set_callback(_callback: Box<dyn Fn([u8; 3]) + Send + Sync>) {
     //
 }
 
diff --git a/kernel-hal-bare/src/arch/x86_64/interrupt.rs b/kernel-hal-bare/src/arch/x86_64/interrupt.rs
index 61ea7335..6aa982d5 100644
--- a/kernel-hal-bare/src/arch/x86_64/interrupt.rs
+++ b/kernel-hal-bare/src/arch/x86_64/interrupt.rs
@@ -22,8 +22,8 @@ lazy_static! {
         Mutex::new(Vec::new());
 }
 
-#[export_name = "hal_mice_set_callback"]
-pub fn mice_set_callback(callback: Box<dyn Fn([u8; 3]) + Send + Sync>) {
+#[export_name = "hal_mouse_set_callback"]
+pub fn mouse_set_callback(callback: Box<dyn Fn([u8; 3]) + Send + Sync>) {
     MOUSE_CALLBACK.lock().push(callback);
 }
 
diff --git a/kernel-hal-bare/src/arch/x86_64/mod.rs b/kernel-hal-bare/src/arch/x86_64/mod.rs
index d76f4f6e..7d3043b9 100644
--- a/kernel-hal-bare/src/arch/x86_64/mod.rs
+++ b/kernel-hal-bare/src/arch/x86_64/mod.rs
@@ -324,7 +324,7 @@ pub fn serial_read(buf: &mut [u8]) -> usize {
 }
 
 #[export_name = "hal_serial_write"]
-pub fn serial_write(s: &str) {
+pub fn print_str(s: &str) {
     putfmt(format_args!("{}", s));
 }
 
diff --git a/kernel-hal/src/common/addr.rs b/kernel-hal/src/common/addr.rs
new file mode 100644
index 00000000..a45fd96b
--- /dev/null
+++ b/kernel-hal/src/common/addr.rs
@@ -0,0 +1,27 @@
+//! Definition of phyical, virtual addresses and helper functions.
+
+use crate::PAGE_SIZE;
+
+pub type PhysAddr = usize;
+pub type VirtAddr = usize;
+pub type DevVAddr = usize;
+
+pub const fn align_down(addr: usize) -> usize {
+    addr & !(PAGE_SIZE - 1)
+}
+
+pub const fn align_up(addr: usize) -> usize {
+    (addr + PAGE_SIZE - 1) & !(PAGE_SIZE - 1)
+}
+
+pub const fn is_aligned(addr: usize) -> bool {
+    page_offset(addr) == 0
+}
+
+pub const fn page_count(size: usize) -> usize {
+    align_up(size) / PAGE_SIZE
+}
+
+pub const fn page_offset(addr: usize) -> usize {
+    addr & (PAGE_SIZE - 1)
+}
diff --git a/kernel-hal/src/common/defs.rs b/kernel-hal/src/common/defs.rs
index 6d35cd7b..841ec47f 100644
--- a/kernel-hal/src/common/defs.rs
+++ b/kernel-hal/src/common/defs.rs
@@ -6,7 +6,7 @@ use numeric_enum_macro::numeric_enum;
 pub struct HalError;
 
 /// The result type returned by HAL functions.
-pub type HalResult<T> = core::result::Result<T, HalError>;
+pub type HalResult<T = ()> = core::result::Result<T, HalError>;
 
 bitflags! {
     pub struct MMUFlags: usize {
@@ -32,7 +32,6 @@ numeric_enum! {
 }
 pub const CACHE_POLICY_MASK: u32 = 3;
 
-pub type PhysAddr = usize;
-pub type VirtAddr = usize;
-pub type DevVAddr = usize;
 pub const PAGE_SIZE: usize = 0x1000;
+
+pub use super::addr::{DevVAddr, PhysAddr, VirtAddr};
diff --git a/kernel-hal/src/common/mod.rs b/kernel-hal/src/common/mod.rs
index f371af86..c6e0d413 100644
--- a/kernel-hal/src/common/mod.rs
+++ b/kernel-hal/src/common/mod.rs
@@ -1,11 +1,10 @@
 pub(super) mod defs;
 pub(super) mod fb;
 
+pub mod addr;
 pub mod context;
 pub mod future;
 pub mod memory;
 pub mod paging;
 pub mod user;
 pub mod vdso;
-
-pub use defs::*;
diff --git a/kernel-hal/src/common/paging.rs b/kernel-hal/src/common/paging.rs
index d29233eb..9f74e20d 100644
--- a/kernel-hal/src/common/paging.rs
+++ b/kernel-hal/src/common/paging.rs
@@ -1,4 +1,4 @@
-use super::{HalResult, MMUFlags, PhysAddr, VirtAddr, PAGE_SIZE};
+use crate::{HalResult, MMUFlags, PhysAddr, VirtAddr, PAGE_SIZE};
 
 pub trait PageTableTrait: Sync + Send {
     /// Map the page of `vaddr` to the frame of `paddr` with `flags`.
diff --git a/kernel-hal/src/common/vdso.rs b/kernel-hal/src/common/vdso.rs
index fa4b1b7b..e1bf1e5d 100644
--- a/kernel-hal/src/common/vdso.rs
+++ b/kernel-hal/src/common/vdso.rs
@@ -1,4 +1,5 @@
 use core::fmt::{Debug, Error, Formatter};
+use git_version::git_version;
 
 /// This struct contains constants that are initialized by the kernel
 /// once at boot time.  From the vDSO code's perspective, they are
@@ -69,3 +70,28 @@ impl Debug for VersionString {
         Ok(())
     }
 }
+
+pub(crate) fn vdso_constants_template() -> VdsoConstants {
+    let frequency = crate::cpu::cpu_frequency();
+    let mut constants = VdsoConstants {
+        max_num_cpus: 1,
+        features: Features {
+            cpu: 0,
+            hw_breakpoint_count: 0,
+            hw_watchpoint_count: 0,
+        },
+        dcache_line_size: 0,
+        icache_line_size: 0,
+        ticks_per_second: frequency as u64 * 1_000_000,
+        ticks_to_mono_numerator: 1000,
+        ticks_to_mono_denominator: frequency as u32,
+        physmem: 0,
+        version_string_len: 0,
+        version_string: Default::default(),
+    };
+    constants.set_version_string(git_version!(
+        prefix = "git-",
+        args = ["--always", "--abbrev=40", "--dirty=-dirty"]
+    ));
+    constants
+}
diff --git a/kernel-hal/src/defs.rs b/kernel-hal/src/defs.rs
new file mode 100644
index 00000000..c8a52366
--- /dev/null
+++ b/kernel-hal/src/defs.rs
@@ -0,0 +1,178 @@
+use alloc::boxed::Box;
+use core::{fmt::Arguments, future::Future, pin::Pin, time::Duration};
+
+use crate::{common, PhysAddr, VirtAddr};
+
+hal_fn_def! {
+    pub mod cpu {
+        /// Current CPU ID.
+        fn cpu_id() -> u8 { 0 }
+
+        /// Current CPU frequency.
+        fn cpu_frequency() -> u16 { 3000 }
+    }
+
+    pub mod memory: common::memory {
+        /// Read physical memory from `paddr` to `buf`.
+        fn pmem_read(paddr: PhysAddr, buf: &mut [u8]);
+
+        /// Write physical memory to `paddr` from `buf`.
+        fn pmem_write(paddr: PhysAddr, buf: &[u8]);
+
+        /// Zero physical memory at `[paddr, paddr + len)`.
+        fn pmem_zero(paddr: PhysAddr, len: usize);
+
+        /// Copy content of `src` frame to `target` frame.
+        fn frame_copy(src: PhysAddr, target: PhysAddr);
+
+        /// Flush the physical frame.
+        fn frame_flush(target: PhysAddr);
+
+        /// Allocate one physical frame.
+        fn frame_alloc() -> Option<PhysAddr>;
+
+        /// Allocate contiguous physical frames of totally `size` bytes.
+        fn frame_alloc_contiguous(size: usize, align_log2: usize) -> Option<PhysAddr>;
+
+        /// Deallocate a physical frame.
+        fn frame_dealloc(paddr: PhysAddr);
+
+        /// Get the physical frame contains all zeros.
+        fn zero_frame_addr() -> PhysAddr;
+    }
+
+    pub mod interrupt {
+        /// Enable IRQ.
+        fn enable_irq(vector: u32);
+
+        /// Disable IRQ.
+        fn disable_irq(vector: u32);
+
+        /// Is a valid IRQ number.
+        fn is_valid_irq(vector: u32) -> bool;
+
+        /// Configure the specified interrupt vector.  If it is invoked, it muust be
+        /// invoked prior to interrupt registration.
+        fn configure_irq(vector: u32, trig_mode: bool, polarity: bool) -> bool;
+
+        /// Add an interrupt handle to an IRQ
+        fn register_irq_handler(vector: u32, handler: Box<dyn Fn() + Send + Sync>) -> Option<u32>;
+
+        /// Remove the interrupt handle to an IRQ
+        fn unregister_irq_handler(vector: u32) -> bool;
+
+        /// Handle IRQ.
+        fn handle_irq(vector: u32);
+
+        /// Method used for platform allocation of blocks of MSI and MSI-X compatible
+        /// IRQ targets.
+        fn msi_allocate_block(irq_num: u32) -> Option<(usize, usize)>;
+
+        /// Method used to free a block of MSI IRQs previously allocated by msi_alloc_block().
+        /// This does not unregister IRQ handlers.
+        fn msi_free_block(irq_start: u32, irq_num: u32);
+
+        /// Register a handler function for a given msi_id within an msi_block_t. Passing a
+        /// NULL handler will effectively unregister a handler for a given msi_id within the
+        /// block.
+        fn msi_register_handler(irq_start: u32, irq_num: u32, msi_id: u32, handler: Box<dyn Fn() + Send + Sync>);
+    }
+
+    pub mod context: common::context {
+        /// Enter user mode.
+        fn context_run(context: &mut UserContext);
+
+        /// Get fault address of the last page fault.
+        fn fetch_fault_vaddr() -> VirtAddr;
+
+        /// Get the trap number when trap.
+        fn fetch_trap_num(context: &UserContext) -> usize;
+    }
+
+    pub mod thread {
+        /// Spawn a new thread.
+        fn spawn(future: Pin<Box<dyn Future<Output = ()> + Send + 'static>>, vmtoken: usize);
+
+        /// Set tid and pid of current task.
+        fn set_tid(tid: u64, pid: u64);
+
+        /// Get tid and pid of current task.]
+        fn get_tid() -> (u64, u64);
+    }
+
+    pub mod timer {
+        /// Get current time.
+        fn timer_now() -> Duration;
+
+        /// Set a new timer. After `deadline`, the `callback` will be called.
+        fn timer_set(deadline: Duration, callback: Box<dyn FnOnce(Duration) + Send + Sync>);
+
+        /// Check timers, call when timer interrupt happened.
+        fn timer_tick();
+    }
+
+    pub mod serial {
+        /// Register a callback of serial readable event.
+        fn serial_set_callback(callback: Box<dyn Fn() -> bool + Send + Sync>);
+
+        /// Put a char to serial buffer.
+        fn serial_put(x: u8);
+
+        /// Read a string from serial buffer.
+        fn serial_read(buf: &mut [u8]) -> usize;
+
+        /// Print format string and its arguments to console.
+        fn print_fmt(fmt: Arguments);
+
+        /// Print a string to console.
+        fn print_str(s: &str) {
+            print_fmt(format_args!("{}", s));
+        }
+    }
+
+    pub mod rand {
+        /// Fill random bytes to the buffer
+        #[allow(unused_variables)]
+        fn fill_random(buf: &mut [u8]) {
+            cfg_if::cfg_if! {
+                if #[cfg(target_arch = "x86_64")] {
+                    // TODO: optimize
+                    for x in buf.iter_mut() {
+                        let mut r = 0;
+                        unsafe {
+                            core::arch::x86_64::_rdrand16_step(&mut r);
+                        }
+                        *x = r as _;
+                    }
+                } else {
+                    unimplemented!()
+                }
+            }
+        }
+    }
+
+    pub mod vdso: common::vdso {
+        /// Get platform specific information.
+        fn vdso_constants() -> VdsoConstants;
+    }
+}
+
+pub mod dev {
+    hal_fn_def! {
+        pub mod fb: crate::common::fb {
+            /// Initialize framebuffer.
+            fn init();
+        }
+
+        pub mod input {
+            /// Initialize input devices.
+            fn init();
+
+            /// Setup the callback when a keyboard event occurs.
+            fn kbd_set_callback(callback: Box<dyn Fn(u16, i32) + Send + Sync>);
+
+            /// Setup the callback when a mouse event occurs.
+            fn mouse_set_callback(callback: Box<dyn Fn([u8; 3]) + Send + Sync>);
+        }
+    }
+}
diff --git a/kernel-hal/src/lib.rs b/kernel-hal/src/lib.rs
index 5bbf7a7c..380b42bb 100644
--- a/kernel-hal/src/lib.rs
+++ b/kernel-hal/src/lib.rs
@@ -6,18 +6,23 @@
 
 extern crate alloc;
 
-mod common;
+#[macro_use]
+extern crate log;
 
-pub use common::{defs::*, future, user};
+#[macro_use]
+mod macros;
+
+mod common;
+mod defs;
+
+pub use common::{addr, defs::*, future, user};
 
 cfg_if::cfg_if! {
     if #[cfg(feature = "libos")] {
-        #[macro_use]
-        extern crate log;
         mod libos;
         pub use self::libos::*;
     } else {
-        mod unimp;
-        pub use self::unimp::*;
+        mod libos;
+        pub use self::libos::*;
     }
 }
diff --git a/kernel-hal/src/libos/context.rs b/kernel-hal/src/libos/context.rs
index 0ff70f0a..7dd900a3 100644
--- a/kernel-hal/src/libos/context.rs
+++ b/kernel-hal/src/libos/context.rs
@@ -1,17 +1,9 @@
-pub use crate::common::context::*;
-
 pub use trapframe::syscall_fn_entry as syscall_entry;
 
-pub fn context_run(context: &mut UserContext) {
-    context.run_fncall();
-}
-
-/// Get fault address of the last page fault.
-pub fn fetch_fault_vaddr() -> crate::VirtAddr {
-    unimplemented!()
-}
-
-/// Get the trap number when trap.
-pub fn fetch_trap_num(_context: &UserContext) -> usize {
-    unimplemented!()
+hal_fn_impl! {
+    impl mod crate::defs::context {
+        fn context_run(context: &mut UserContext) {
+            context.run_fncall();
+        }
+    }
 }
diff --git a/kernel-hal/src/libos/cpu.rs b/kernel-hal/src/libos/cpu.rs
deleted file mode 100644
index ec6bd3b3..00000000
--- a/kernel-hal/src/libos/cpu.rs
+++ /dev/null
@@ -1,3 +0,0 @@
-pub fn u8() -> u8 {
-    0
-}
diff --git a/kernel-hal/src/libos/dev/fb.rs b/kernel-hal/src/libos/dev/fb.rs
index 6bfe7b2f..2c6f2f34 100644
--- a/kernel-hal/src/libos/dev/fb.rs
+++ b/kernel-hal/src/libos/dev/fb.rs
@@ -74,59 +74,63 @@ struct FbBitfield {
     msb_right: u32,
 }
 
-pub fn init() {
-    const FBIOGET_VSCREENINFO: u64 = 0x4600;
-    const FBIOGET_FSCREENINFO: u64 = 0x4602;
+hal_fn_impl! {
+    impl mod crate::defs::dev::fb {
+        fn init() {
+            const FBIOGET_VSCREENINFO: u64 = 0x4600;
+            const FBIOGET_FSCREENINFO: u64 = 0x4602;
 
-    #[cfg(target_arch = "aarch64")]
-    let fbfd = unsafe { libc::open("/dev/fb0".as_ptr(), libc::O_RDWR) };
-    #[cfg(not(target_arch = "aarch64"))]
-    let fbfd = unsafe { libc::open("/dev/fb0".as_ptr() as *const i8, libc::O_RDWR) };
-    if fbfd < 0 {
-        return;
+            #[cfg(target_arch = "aarch64")]
+            let fbfd = unsafe { libc::open("/dev/fb0".as_ptr(), libc::O_RDWR) };
+            #[cfg(not(target_arch = "aarch64"))]
+            let fbfd = unsafe { libc::open("/dev/fb0".as_ptr() as *const i8, libc::O_RDWR) };
+            if fbfd < 0 {
+                return;
+            }
+
+            let mut vinfo = FbVarScreeninfo::default();
+            if unsafe { libc::ioctl(fbfd, FBIOGET_VSCREENINFO, &mut vinfo) } < 0 {
+                return;
+            }
+
+            let mut finfo = FbFixScreeninfo::default();
+            if unsafe { libc::ioctl(fbfd, FBIOGET_FSCREENINFO, &mut finfo) } < 0 {
+                return;
+            }
+
+            let size = finfo.size() as usize;
+            let addr = unsafe {
+                libc::mmap(
+                    std::ptr::null_mut::<libc::c_void>(),
+                    size,
+                    libc::PROT_READ | libc::PROT_WRITE,
+                    libc::MAP_SHARED,
+                    fbfd,
+                    0,
+                )
+            };
+            if (addr as isize) < 0 {
+                return;
+            }
+
+            let (width, height) = vinfo.resolution();
+            let addr = addr as usize;
+
+            let fb_info = FramebufferInfo {
+                xres: width,
+                yres: height,
+                xres_virtual: width,
+                yres_virtual: height,
+                xoffset: 0,
+                yoffset: 0,
+                depth: ColorDepth::ColorDepth32,
+                format: ColorFormat::RGBA8888,
+                // paddr: virt_to_phys(addr),
+                paddr: addr,
+                vaddr: addr,
+                screen_size: size,
+            };
+            *FRAME_BUFFER.write() = Some(fb_info);
+        }
     }
-
-    let mut vinfo = FbVarScreeninfo::default();
-    if unsafe { libc::ioctl(fbfd, FBIOGET_VSCREENINFO, &mut vinfo) } < 0 {
-        return;
-    }
-
-    let mut finfo = FbFixScreeninfo::default();
-    if unsafe { libc::ioctl(fbfd, FBIOGET_FSCREENINFO, &mut finfo) } < 0 {
-        return;
-    }
-
-    let size = finfo.size() as usize;
-    let addr = unsafe {
-        libc::mmap(
-            std::ptr::null_mut::<libc::c_void>(),
-            size,
-            libc::PROT_READ | libc::PROT_WRITE,
-            libc::MAP_SHARED,
-            fbfd,
-            0,
-        )
-    };
-    if (addr as isize) < 0 {
-        return;
-    }
-
-    let (width, height) = vinfo.resolution();
-    let addr = addr as usize;
-
-    let fb_info = FramebufferInfo {
-        xres: width,
-        yres: height,
-        xres_virtual: width,
-        yres_virtual: height,
-        xoffset: 0,
-        yoffset: 0,
-        depth: ColorDepth::ColorDepth32,
-        format: ColorFormat::RGBA8888,
-        // paddr: virt_to_phys(addr),
-        paddr: addr,
-        vaddr: addr,
-        screen_size: size,
-    };
-    *FRAME_BUFFER.write() = Some(fb_info);
 }
diff --git a/kernel-hal/src/libos/dev/input.rs b/kernel-hal/src/libos/dev/input.rs
index 942f94c7..ca9746ed 100644
--- a/kernel-hal/src/libos/dev/input.rs
+++ b/kernel-hal/src/libos/dev/input.rs
@@ -82,15 +82,19 @@ fn init_mice() {
     });
 }
 
-pub fn mice_set_callback(callback: Box<dyn Fn([u8; 3]) + Send + Sync>) {
-    MOUSE_CALLBACK.lock().unwrap().push(callback);
-}
+hal_fn_impl! {
+    impl mod crate::defs::dev::input {
+        fn kbd_set_callback(callback: Box<dyn Fn(u16, i32) + Send + Sync>) {
+            KBD_CALLBACK.lock().unwrap().push(callback);
+        }
 
-pub fn kbd_set_callback(callback: Box<dyn Fn(u16, i32) + Send + Sync>) {
-    KBD_CALLBACK.lock().unwrap().push(callback);
-}
+        fn mouse_set_callback(callback: Box<dyn Fn([u8; 3]) + Send + Sync>) {
+            MOUSE_CALLBACK.lock().unwrap().push(callback);
+        }
 
-pub fn init() {
-    init_kbd();
-    init_mice();
+        fn init() {
+            init_kbd();
+            init_mice();
+        }
+    }
 }
diff --git a/kernel-hal/src/libos/memory.rs b/kernel-hal/src/libos/memory.rs
index 79394122..d3c4d9ba 100644
--- a/kernel-hal/src/libos/memory.rs
+++ b/kernel-hal/src/libos/memory.rs
@@ -1,69 +1,71 @@
 use super::mem_common::{ensure_mmap_pmem, phys_to_virt, AVAILABLE_FRAMES, PMEM_SIZE};
 use crate::{PhysAddr, PAGE_SIZE};
 
-pub use crate::common::memory::*;
+hal_fn_impl! {
+    impl mod crate::defs::memory {
+        /// Read physical memory from `paddr` to `buf`.
+        fn pmem_read(paddr: PhysAddr, buf: &mut [u8]) {
+            trace!("pmem read: paddr={:#x}, len={:#x}", paddr, buf.len());
+            assert!(paddr + buf.len() <= PMEM_SIZE);
+            ensure_mmap_pmem();
+            unsafe {
+                (phys_to_virt(paddr) as *const u8).copy_to_nonoverlapping(buf.as_mut_ptr(), buf.len());
+            }
+        }
 
-/// Read physical memory from `paddr` to `buf`.
-pub fn pmem_read(paddr: PhysAddr, buf: &mut [u8]) {
-    trace!("pmem read: paddr={:#x}, len={:#x}", paddr, buf.len());
-    assert!(paddr + buf.len() <= PMEM_SIZE);
-    ensure_mmap_pmem();
-    unsafe {
-        (phys_to_virt(paddr) as *const u8).copy_to_nonoverlapping(buf.as_mut_ptr(), buf.len());
+        /// Write physical memory to `paddr` from `buf`.
+        fn pmem_write(paddr: PhysAddr, buf: &[u8]) {
+            trace!("pmem write: paddr={:#x}, len={:#x}", paddr, buf.len());
+            assert!(paddr + buf.len() <= PMEM_SIZE);
+            ensure_mmap_pmem();
+            unsafe {
+                buf.as_ptr()
+                    .copy_to_nonoverlapping(phys_to_virt(paddr) as _, buf.len());
+            }
+        }
+
+        /// Zero physical memory at `[paddr, paddr + len)`
+        fn pmem_zero(paddr: PhysAddr, len: usize) {
+            trace!("pmem_zero: addr={:#x}, len={:#x}", paddr, len);
+            assert!(paddr + len <= PMEM_SIZE);
+            ensure_mmap_pmem();
+            unsafe {
+                core::ptr::write_bytes(phys_to_virt(paddr) as *mut u8, 0, len);
+            }
+        }
+
+        /// Copy content of `src` frame to `target` frame
+        fn frame_copy(src: PhysAddr, target: PhysAddr) {
+            trace!("frame_copy: {:#x} <- {:#x}", target, src);
+            assert!(src + PAGE_SIZE <= PMEM_SIZE && target + PAGE_SIZE <= PMEM_SIZE);
+            ensure_mmap_pmem();
+            unsafe {
+                let buf = phys_to_virt(src) as *const u8;
+                buf.copy_to_nonoverlapping(phys_to_virt(target) as _, PAGE_SIZE);
+            }
+        }
+
+        fn frame_flush(_target: PhysAddr) {
+            // do nothing
+        }
+
+        fn frame_alloc() -> Option<PhysAddr> {
+            let ret = AVAILABLE_FRAMES.lock().unwrap().pop_front();
+            trace!("frame alloc: {:?}", ret);
+            ret
+        }
+
+        fn frame_alloc_contiguous(_size: usize, _align_log2: usize) -> Option<PhysAddr> {
+            unimplemented!()
+        }
+
+        fn frame_dealloc(paddr: PhysAddr) {
+            trace!("frame dealloc: {:?}", paddr);
+            AVAILABLE_FRAMES.lock().unwrap().push_back(paddr);
+        }
+
+        fn zero_frame_addr() -> PhysAddr {
+            0
+        }
     }
 }
-
-/// Write physical memory to `paddr` from `buf`.
-pub fn pmem_write(paddr: PhysAddr, buf: &[u8]) {
-    trace!("pmem write: paddr={:#x}, len={:#x}", paddr, buf.len());
-    assert!(paddr + buf.len() <= PMEM_SIZE);
-    ensure_mmap_pmem();
-    unsafe {
-        buf.as_ptr()
-            .copy_to_nonoverlapping(phys_to_virt(paddr) as _, buf.len());
-    }
-}
-
-/// Zero physical memory at `[paddr, paddr + len)`
-pub fn pmem_zero(paddr: PhysAddr, len: usize) {
-    trace!("pmem_zero: addr={:#x}, len={:#x}", paddr, len);
-    assert!(paddr + len <= PMEM_SIZE);
-    ensure_mmap_pmem();
-    unsafe {
-        core::ptr::write_bytes(phys_to_virt(paddr) as *mut u8, 0, len);
-    }
-}
-
-/// Copy content of `src` frame to `target` frame
-pub fn frame_copy(src: PhysAddr, target: PhysAddr) {
-    trace!("frame_copy: {:#x} <- {:#x}", target, src);
-    assert!(src + PAGE_SIZE <= PMEM_SIZE && target + PAGE_SIZE <= PMEM_SIZE);
-    ensure_mmap_pmem();
-    unsafe {
-        let buf = phys_to_virt(src) as *const u8;
-        buf.copy_to_nonoverlapping(phys_to_virt(target) as _, PAGE_SIZE);
-    }
-}
-
-pub fn frame_flush(_target: PhysAddr) {
-    // do nothing
-}
-
-pub fn frame_alloc() -> Option<PhysAddr> {
-    let ret = AVAILABLE_FRAMES.lock().unwrap().pop_front();
-    trace!("frame alloc: {:?}", ret);
-    ret
-}
-
-pub fn frame_alloc_contiguous(_size: usize, _align_log2: usize) -> Option<PhysAddr> {
-    unimplemented!()
-}
-
-pub fn frame_dealloc(paddr: PhysAddr) {
-    trace!("frame dealloc: {:?}", paddr);
-    AVAILABLE_FRAMES.lock().unwrap().push_back(paddr);
-}
-
-pub fn zero_frame_addr() -> PhysAddr {
-    0
-}
diff --git a/kernel-hal/src/libos/mod.rs b/kernel-hal/src/libos/mod.rs
index 4f6b8c7e..18a26dbd 100644
--- a/kernel-hal/src/libos/mod.rs
+++ b/kernel-hal/src/libos/mod.rs
@@ -1,7 +1,6 @@
 mod mem_common;
 
 pub mod context;
-pub mod cpu;
 pub mod memory;
 pub mod paging;
 pub mod serial;
@@ -9,17 +8,16 @@ pub mod thread;
 pub mod timer;
 pub mod vdso;
 
-#[path = "../unimp/interrupt.rs"]
-pub mod interrupt;
-#[path = "../unimp/rand.rs"]
-pub mod rand;
+pub use super::defs::{cpu, interrupt, rand};
+
+hal_fn_impl_default!(rand, interrupt, cpu);
 
 cfg_if::cfg_if! {
     if #[cfg(target_os = "linux")] {
         pub mod dev;
     } else {
-        #[path = "../unimp/dev/mod.rs"]
-        pub mod dev;
+        pub use super::defs::dev;
+        hal_fn_impl_default!(dev::fb, dev::input);
     }
 }
 
@@ -43,8 +41,3 @@ pub fn init() {
         }
     });
 }
-
-// FIXME
-#[path = "../unimp/misc.rs"]
-mod misc;
-pub use misc::*;
diff --git a/kernel-hal/src/libos/paging.rs b/kernel-hal/src/libos/paging.rs
index bc626505..7d424734 100644
--- a/kernel-hal/src/libos/paging.rs
+++ b/kernel-hal/src/libos/paging.rs
@@ -2,7 +2,7 @@ use std::io::Error;
 use std::os::unix::io::AsRawFd;
 
 use super::mem_common::{mmap, FRAME_FILE};
-use crate::{HalResult, MMUFlags, PhysAddr, VirtAddr, PAGE_SIZE};
+use crate::{addr::is_aligned, HalResult, MMUFlags, PhysAddr, VirtAddr, PAGE_SIZE};
 
 pub use crate::common::paging::*;
 
@@ -22,8 +22,8 @@ impl PageTable {
 impl PageTableTrait for PageTable {
     /// Map the page of `vaddr` to the frame of `paddr` with `flags`.
     fn map(&mut self, vaddr: VirtAddr, paddr: PhysAddr, flags: MMUFlags) -> HalResult<()> {
-        debug_assert!(page_aligned(vaddr));
-        debug_assert!(page_aligned(paddr));
+        debug_assert!(is_aligned(vaddr));
+        debug_assert!(is_aligned(paddr));
         let prot = flags.to_mmap_prot();
         mmap(FRAME_FILE.as_raw_fd(), paddr, PAGE_SIZE, vaddr, prot);
         Ok(())
@@ -36,7 +36,7 @@ impl PageTableTrait for PageTable {
 
     /// Change the `flags` of the page of `vaddr`.
     fn protect(&mut self, vaddr: VirtAddr, flags: MMUFlags) -> HalResult<()> {
-        debug_assert!(page_aligned(vaddr));
+        debug_assert!(is_aligned(vaddr));
         let prot = flags.to_mmap_prot();
         let ret = unsafe { libc::mprotect(vaddr as _, PAGE_SIZE, prot) };
         assert_eq!(ret, 0, "failed to mprotect: {:?}", Error::last_os_error());
@@ -45,7 +45,7 @@ impl PageTableTrait for PageTable {
 
     /// Query the physical address which the page of `vaddr` maps to.
     fn query(&mut self, vaddr: VirtAddr) -> HalResult<PhysAddr> {
-        debug_assert!(page_aligned(vaddr));
+        debug_assert!(is_aligned(vaddr));
         unimplemented!()
     }
 
@@ -58,17 +58,13 @@ impl PageTableTrait for PageTable {
         if pages == 0 {
             return Ok(());
         }
-        debug_assert!(page_aligned(vaddr));
+        debug_assert!(is_aligned(vaddr));
         let ret = unsafe { libc::munmap(vaddr as _, PAGE_SIZE * pages) };
         assert_eq!(ret, 0, "failed to munmap: {:?}", Error::last_os_error());
         Ok(())
     }
 }
 
-fn page_aligned(x: VirtAddr) -> bool {
-    x % PAGE_SIZE == 0
-}
-
 trait FlagsExt {
     fn to_mmap_prot(&self) -> libc::c_int;
 }
diff --git a/kernel-hal/src/libos/serial.rs b/kernel-hal/src/libos/serial.rs
index 4bec441b..1cec912b 100644
--- a/kernel-hal/src/libos/serial.rs
+++ b/kernel-hal/src/libos/serial.rs
@@ -8,26 +8,28 @@ lazy_static! {
         Mutex::new(Vec::new());
 }
 
-/// Put a char by serial interrupt handler.
-pub fn serial_put(x: u8) {
-    STDIN.lock().unwrap().push_back(x);
-    STDIN_CALLBACK.lock().unwrap().retain(|f| !f());
-}
+hal_fn_impl! {
+    impl mod crate::defs::serial {
+        fn serial_put(x: u8) {
+            STDIN.lock().unwrap().push_back(x);
+            STDIN_CALLBACK.lock().unwrap().retain(|f| !f());
+        }
 
-pub fn serial_set_callback(callback: Box<dyn Fn() -> bool + Send + Sync>) {
-    STDIN_CALLBACK.lock().unwrap().push(callback);
-}
+        fn serial_set_callback(callback: Box<dyn Fn() -> bool + Send + Sync>) {
+            STDIN_CALLBACK.lock().unwrap().push(callback);
+        }
 
-pub fn serial_read(buf: &mut [u8]) -> usize {
-    let mut stdin = STDIN.lock().unwrap();
-    let len = stdin.len().min(buf.len());
-    for c in &mut buf[..len] {
-        *c = stdin.pop_front().unwrap();
+        fn serial_read(buf: &mut [u8]) -> usize {
+            let mut stdin = STDIN.lock().unwrap();
+            let len = stdin.len().min(buf.len());
+            for c in &mut buf[..len] {
+                *c = stdin.pop_front().unwrap();
+            }
+            len
+        }
+
+        fn print_fmt(fmt: core::fmt::Arguments) {
+            eprint!("{}", fmt);
+        }
     }
-    len
-}
-
-/// Output a char to console.
-pub fn serial_write(s: &str) {
-    eprint!("{}", s);
 }
diff --git a/kernel-hal/src/libos/thread.rs b/kernel-hal/src/libos/thread.rs
index 1fc66846..93358d86 100644
--- a/kernel-hal/src/libos/thread.rs
+++ b/kernel-hal/src/libos/thread.rs
@@ -6,15 +6,19 @@ task_local! {
     static PID: Cell<u64> = Cell::new(0);
 }
 
-pub fn spawn(future: Pin<Box<dyn Future<Output = ()> + Send + 'static>>, _vmtoken: usize) {
-    async_std::task::spawn(future);
-}
+hal_fn_impl! {
+    impl mod crate::defs::thread {
+        fn spawn(future: Pin<Box<dyn Future<Output = ()> + Send + 'static>>, _vmtoken: usize) {
+            async_std::task::spawn(future);
+        }
 
-pub fn set_tid(tid: u64, pid: u64) {
-    TID.with(|x| x.set(tid));
-    PID.with(|x| x.set(pid));
-}
+        fn set_tid(tid: u64, pid: u64) {
+            TID.with(|x| x.set(tid));
+            PID.with(|x| x.set(pid));
+        }
 
-pub fn get_tid() -> (u64, u64) {
-    (TID.with(|x| x.get()), PID.with(|x| x.get()))
+        fn get_tid() -> (u64, u64) {
+            (TID.with(|x| x.get()), PID.with(|x| x.get()))
+        }
+    }
 }
diff --git a/kernel-hal/src/libos/timer.rs b/kernel-hal/src/libos/timer.rs
index 173d4d55..e7b4ac57 100644
--- a/kernel-hal/src/libos/timer.rs
+++ b/kernel-hal/src/libos/timer.rs
@@ -1,21 +1,25 @@
 use std::time::{Duration, SystemTime};
 
-/// Get current time.
-pub fn timer_now() -> Duration {
-    SystemTime::now()
-        .duration_since(SystemTime::UNIX_EPOCH)
-        .unwrap()
-}
-
-/// Set a new timer.
-///
-/// After `deadline`, the `callback` will be called.
-pub fn timer_set(deadline: Duration, callback: Box<dyn FnOnce(Duration) + Send + Sync>) {
-    std::thread::spawn(move || {
-        let now = timer_now();
-        if deadline > now {
-            std::thread::sleep(deadline - now);
+hal_fn_impl! {
+    impl mod crate::defs::timer {
+        /// Get current time.
+        fn timer_now() -> Duration {
+            SystemTime::now()
+                .duration_since(SystemTime::UNIX_EPOCH)
+                .unwrap()
         }
-        callback(timer_now());
-    });
+
+        /// Set a new timer.
+        ///
+        /// After `deadline`, the `callback` will be called.
+        fn timer_set(deadline: Duration, callback: Box<dyn FnOnce(Duration) + Send + Sync>) {
+            std::thread::spawn(move || {
+                let now = timer_now();
+                if deadline > now {
+                    std::thread::sleep(deadline - now);
+                }
+                callback(timer_now());
+            });
+        }
+    }
 }
diff --git a/kernel-hal/src/libos/vdso.rs b/kernel-hal/src/libos/vdso.rs
index 0356b4d2..27e655e3 100644
--- a/kernel-hal/src/libos/vdso.rs
+++ b/kernel-hal/src/libos/vdso.rs
@@ -1,30 +1,9 @@
-use git_version::git_version;
-
-use super::mem_common::PMEM_SIZE;
-
-pub use crate::common::vdso::*;
-
-pub fn vdso_constants() -> VdsoConstants {
-    let tsc_frequency = 3000u16;
-    let mut constants = VdsoConstants {
-        max_num_cpus: 1,
-        features: Features {
-            cpu: 0,
-            hw_breakpoint_count: 0,
-            hw_watchpoint_count: 0,
-        },
-        dcache_line_size: 0,
-        icache_line_size: 0,
-        ticks_per_second: tsc_frequency as u64 * 1_000_000,
-        ticks_to_mono_numerator: 1000,
-        ticks_to_mono_denominator: tsc_frequency as u32,
-        physmem: PMEM_SIZE as u64,
-        version_string_len: 0,
-        version_string: Default::default(),
-    };
-    constants.set_version_string(git_version!(
-        prefix = "git-",
-        args = ["--always", "--abbrev=40", "--dirty=-dirty"]
-    ));
-    constants
+hal_fn_impl! {
+    impl mod crate::defs::vdso {
+        fn vdso_constants() -> VdsoConstants {
+            let mut constants = vdso_constants_template();
+            constants.physmem = super::mem_common::PMEM_SIZE as u64;
+            constants
+        }
+    }
 }
diff --git a/kernel-hal/src/macros.rs b/kernel-hal/src/macros.rs
new file mode 100644
index 00000000..5a2838c6
--- /dev/null
+++ b/kernel-hal/src/macros.rs
@@ -0,0 +1,167 @@
+macro_rules! hal_fn_def {
+    (
+        $(
+            $vis:vis mod $mod_name:ident $( : $base:path )? {
+                $($fn:tt)*
+            }
+        )+
+    ) => {
+        $(
+            $vis mod $mod_name {
+                #![allow(unused_imports)]
+                $( pub use $base::*; )?
+                use super::*;
+                pub(crate) trait __HalTrait {
+                    __hal_fn_default_imp! {
+                        $($fn)*
+                    }
+                }
+                pub(crate) struct __HalImpl;
+                __hal_fn_export! {
+                    $($fn)*
+                }
+            }
+        )+
+    };
+    () => {};
+}
+
+macro_rules! hal_fn_impl {
+    (
+        $(
+            impl mod $mod_name:ident$(::$mod_name_more:ident)* {
+                $($fn:item)*
+            }
+        )+
+    ) => {
+        $(
+            __hal_fn_impl_no_export! {
+                impl mod $mod_name$(::$mod_name_more)* {
+                    $($fn)*
+                }
+            }
+            pub use $mod_name$(::$mod_name_more)*::*;
+        )+
+    };
+    () => {};
+}
+
+macro_rules! hal_fn_impl_default {
+    (
+        $( $mod_name:ident$(::$mod_name_more:ident)* ),*
+    ) => {
+        __hal_fn_impl_no_export! {
+            $( impl mod $mod_name$(::$mod_name_more)* {} )*
+        }
+    }
+}
+
+macro_rules! __hal_fn_default_imp {
+    (
+        $(#[$inner:ident $($args:tt)*])*
+        fn $fn:ident ( $($arg:ident : $type:ty),* ) $( -> $ret:ty )?;
+        $($tail:tt)*
+    ) => {
+        $(#[$inner $($args)*])*
+        #[allow(unused_variables)]
+        fn $fn ( $($arg : $type),* ) $( -> $ret )? {
+            unimplemented!();
+        }
+        __hal_fn_default_imp! {
+            $($tail)*
+        }
+    };
+    (
+        $(#[$inner:ident $($args:tt)*])*
+        fn $fn:ident ( $($arg:ident : $type:ty),* ) $( -> $ret:ty )? $body:block
+        $($tail:tt)*
+    ) => {
+        $(#[$inner $($args)*])*
+        fn $fn ( $($arg : $type),* ) $( -> $ret )? $body
+        __hal_fn_default_imp! {
+            $($tail)*
+        }
+    };
+    () => {};
+}
+
+macro_rules! __hal_fn_export {
+    (
+        $(#[$inner:ident $($args:tt)*])*
+        fn $fn:ident ( $($arg:ident : $type:ty),* ) $( -> $ret:ty )?;
+        $($tail:tt)*
+    ) => {
+        $(#[$inner $($args)*])*
+        #[allow(dead_code)]
+        pub fn $fn ( $($arg : $type),* ) $( -> $ret )? {
+            __HalImpl::$fn( $($arg),* )
+        }
+        __hal_fn_export! {
+            $($tail)*
+        }
+    };
+    (
+        $(#[$inner:ident $($args:tt)*])*
+        fn $fn:ident ( $($arg:ident : $type:ty),* ) $( -> $ret:ty )? $body:block
+        $($tail:tt)*
+    ) => {
+        $(#[$inner $($args)*])*
+        #[allow(dead_code)]
+        pub fn $fn ( $($arg : $type),* ) $( -> $ret )? {
+            __HalImpl::$fn( $($arg),* )
+        }
+        __hal_fn_export! {
+            $($tail)*
+        }
+    };
+    () => {};
+}
+
+macro_rules! __hal_fn_impl_no_export {
+    (
+        $(
+            impl mod $mod_name:ident$(::$mod_name_more:ident)* {
+                $($fn:item)*
+            }
+        )+
+    ) => {
+        $(
+            impl $mod_name$(::$mod_name_more)*::__HalTrait for $mod_name$(::$mod_name_more)*::__HalImpl {
+                $($fn)*
+            }
+        )+
+    };
+    () => {};
+}
+
+#[cfg(test)]
+mod test {
+    mod base {
+        pub const BASE: usize = 0x2333;
+    }
+    hal_fn_def! {
+        mod mod0: self::base {
+            fn test() -> f32 { 1.0 }
+        }
+        mod mod1 {
+            fn foo() -> usize { 0 }
+            fn bar(a: usize) -> usize { a }
+            fn unimp();
+        }
+    }
+    hal_fn_impl! {
+        impl mod self::mod1 {
+            fn foo() -> usize { 233 }
+        }
+    }
+    hal_fn_impl_default!(mod0);
+
+    #[test]
+    fn test_hal_fn_marco() {
+        assert_eq!(mod0::BASE, 0x2333);
+        assert_eq!(mod0::test(), 1.0);
+        assert_eq!(mod1::foo(), 233);
+        assert_eq!(mod1::bar(0), 0);
+        // base::unimp(); // unimplemented!
+    }
+}
diff --git a/kernel-hal/src/unimp/context.rs b/kernel-hal/src/unimp/context.rs
deleted file mode 100644
index b8817bf9..00000000
--- a/kernel-hal/src/unimp/context.rs
+++ /dev/null
@@ -1,15 +0,0 @@
-pub use crate::common::context::*;
-
-pub fn context_run(_context: &mut UserContext) {
-    unimplemented!()
-}
-
-/// Get fault address of the last page fault.
-pub fn fetch_fault_vaddr() -> crate::VirtAddr {
-    unimplemented!()
-}
-
-/// Get the trap number when trap.
-pub fn fetch_trap_num(_context: &UserContext) -> usize {
-    unimplemented!()
-}
diff --git a/kernel-hal/src/unimp/cpu.rs b/kernel-hal/src/unimp/cpu.rs
deleted file mode 100644
index bb996897..00000000
--- a/kernel-hal/src/unimp/cpu.rs
+++ /dev/null
@@ -1,3 +0,0 @@
-pub fn cpu_id() -> u8 {
-    0
-}
diff --git a/kernel-hal/src/unimp/dev/fb.rs b/kernel-hal/src/unimp/dev/fb.rs
deleted file mode 100644
index f5af892b..00000000
--- a/kernel-hal/src/unimp/dev/fb.rs
+++ /dev/null
@@ -1,5 +0,0 @@
-pub use crate::common::fb::*;
-
-pub fn init() {
-    unimplemented!()
-}
diff --git a/kernel-hal/src/unimp/dev/input.rs b/kernel-hal/src/unimp/dev/input.rs
deleted file mode 100644
index cb4d18b3..00000000
--- a/kernel-hal/src/unimp/dev/input.rs
+++ /dev/null
@@ -1,13 +0,0 @@
-use alloc::boxed::Box;
-
-pub fn kbd_set_callback(_callback: Box<dyn Fn(u16, i32) + Send + Sync>) {
-    unimplemented!()
-}
-
-pub fn mice_set_callback(_callback: Box<dyn Fn([u8; 3]) + Send + Sync>) {
-    unimplemented!()
-}
-
-pub fn init() {
-    unimplemented!()
-}
diff --git a/kernel-hal/src/unimp/dev/mod.rs b/kernel-hal/src/unimp/dev/mod.rs
deleted file mode 100644
index 087d3867..00000000
--- a/kernel-hal/src/unimp/dev/mod.rs
+++ /dev/null
@@ -1,2 +0,0 @@
-pub mod fb;
-pub mod input;
diff --git a/kernel-hal/src/unimp/interrupt.rs b/kernel-hal/src/unimp/interrupt.rs
deleted file mode 100644
index 96528329..00000000
--- a/kernel-hal/src/unimp/interrupt.rs
+++ /dev/null
@@ -1,61 +0,0 @@
-use alloc::boxed::Box;
-
-/// Enable IRQ.
-pub fn enable_irq(_vector: u32) {
-    unimplemented!()
-}
-
-/// Disable IRQ.
-pub fn disable_irq(_vector: u32) {
-    unimplemented!()
-}
-
-/// Is a valid IRQ number.
-pub fn is_valid_irq(_vector: u32) -> bool {
-    unimplemented!()
-}
-
-/// Configure the specified interrupt vector.  If it is invoked, it muust be
-/// invoked prior to interrupt registration.
-pub fn configure_irq(_vector: u32, _trig_mode: bool, _polarity: bool) -> bool {
-    unimplemented!()
-}
-
-/// Add an interrupt handle to an IRQ
-pub fn register_irq_handler(_vector: u32, _handle: Box<dyn Fn() + Send + Sync>) -> Option<u32> {
-    unimplemented!()
-}
-
-/// Remove the interrupt handle to an IRQ
-pub fn unregister_irq_handler(_vector: u32) -> bool {
-    unimplemented!()
-}
-
-/// Handle IRQ.
-pub fn handle_irq(_vector: u32) {
-    unimplemented!()
-}
-
-/// Method used for platform allocation of blocks of MSI and MSI-X compatible
-/// IRQ targets.
-pub fn msi_allocate_block(_irq_num: u32) -> Option<(usize, usize)> {
-    unimplemented!()
-}
-
-/// Method used to free a block of MSI IRQs previously allocated by msi_alloc_block().
-/// This does not unregister IRQ handlers.
-pub fn msi_free_block(_irq_start: u32, _irq_num: u32) {
-    unimplemented!()
-}
-
-/// Register a handler function for a given msi_id within an msi_block_t. Passing a
-/// NULL handler will effectively unregister a handler for a given msi_id within the
-/// block.
-pub fn msi_register_handler(
-    _irq_start: u32,
-    _irq_num: u32,
-    _msi_id: u32,
-    _handle: Box<dyn Fn() + Send + Sync>,
-) {
-    unimplemented!()
-}
diff --git a/kernel-hal/src/unimp/memory.rs b/kernel-hal/src/unimp/memory.rs
deleted file mode 100644
index 7bbbb2fb..00000000
--- a/kernel-hal/src/unimp/memory.rs
+++ /dev/null
@@ -1,44 +0,0 @@
-use crate::PhysAddr;
-
-pub use crate::common::memory::*;
-
-/// Read physical memory from `paddr` to `buf`.
-pub fn pmem_read(_paddr: PhysAddr, _buf: &mut [u8]) {
-    unimplemented!()
-}
-
-/// Write physical memory to `paddr` from `buf`.
-pub fn pmem_write(_paddr: PhysAddr, _buf: &[u8]) {
-    unimplemented!()
-}
-
-/// Zero physical memory at `[paddr, paddr + len)`.
-pub fn pmem_zero(_paddr: PhysAddr, _len: usize) {
-    unimplemented!()
-}
-
-/// Copy content of `src` frame to `target` frame.
-pub fn frame_copy(_src: PhysAddr, _target: PhysAddr) {
-    unimplemented!()
-}
-
-/// Flush the physical frame.
-pub fn frame_flush(_target: PhysAddr) {
-    unimplemented!()
-}
-
-pub fn frame_alloc() -> Option<PhysAddr> {
-    unimplemented!()
-}
-
-pub fn frame_alloc_contiguous(_size: usize, _align_log2: usize) -> Option<PhysAddr> {
-    unimplemented!()
-}
-
-pub fn frame_dealloc(_paddr: PhysAddr) {
-    unimplemented!()
-}
-
-pub fn zero_frame_addr() -> PhysAddr {
-    unimplemented!()
-}
diff --git a/kernel-hal/src/unimp/misc.rs b/kernel-hal/src/unimp/misc.rs
deleted file mode 100644
index f7ab2319..00000000
--- a/kernel-hal/src/unimp/misc.rs
+++ /dev/null
@@ -1,35 +0,0 @@
-use crate::{context::UserContext, VirtAddr};
-use acpi::Acpi;
-
-/// Get fault address of the last page fault.
-pub fn fetch_fault_vaddr() -> VirtAddr {
-    unimplemented!()
-}
-
-pub fn fetch_trap_num(_context: &UserContext) -> usize {
-    unimplemented!()
-}
-
-/// Get physical address of `acpi_rsdp` and `smbios` on x86_64.
-pub fn pc_firmware_tables() -> (u64, u64) {
-    unimplemented!()
-}
-
-/// Get ACPI Table
-pub fn get_acpi_table() -> Option<Acpi> {
-    unimplemented!()
-}
-
-/// IO Ports access on x86 platform
-pub fn outpd(_port: u16, _value: u32) {
-    unimplemented!()
-}
-
-pub fn inpd(_port: u16) -> u32 {
-    unimplemented!()
-}
-
-/// Get local APIC ID
-pub fn apic_local_id() -> u8 {
-    unimplemented!()
-}
diff --git a/kernel-hal/src/unimp/mod.rs b/kernel-hal/src/unimp/mod.rs
deleted file mode 100644
index 3c9b6899..00000000
--- a/kernel-hal/src/unimp/mod.rs
+++ /dev/null
@@ -1,21 +0,0 @@
-pub mod context;
-pub mod cpu;
-pub mod dev;
-pub mod interrupt;
-pub mod memory;
-pub mod misc;
-pub mod paging;
-pub mod rand;
-pub mod serial;
-pub mod thread;
-pub mod timer;
-pub mod vdso;
-
-pub use self::misc::*; // FIXME
-
-/// Initialize the HAL.
-///
-/// This function must be called at the beginning.
-pub fn init() {
-    unimplemented!();
-}
diff --git a/kernel-hal/src/unimp/paging.rs b/kernel-hal/src/unimp/paging.rs
deleted file mode 100644
index e4e65069..00000000
--- a/kernel-hal/src/unimp/paging.rs
+++ /dev/null
@@ -1,50 +0,0 @@
-use crate::{HalResult, MMUFlags, PhysAddr, VirtAddr};
-
-pub use crate::common::paging::*;
-
-pub struct PageTable;
-
-impl PageTable {
-    /// Create a new `PageTable`.
-    pub fn new() -> Self {
-        PageTable
-    }
-
-    /// Get the current root page table physical address. (e.g. CR3, SATP, ...)
-    pub fn current() -> Self {
-        unimplemented!();
-    }
-}
-
-impl PageTableTrait for PageTable {
-    /// Map the page of `vaddr` to the frame of `paddr` with `flags`.
-    fn map(&mut self, _vaddr: VirtAddr, _paddr: PhysAddr, _flags: MMUFlags) -> HalResult<()> {
-        unimplemented!();
-    }
-
-    /// Unmap the page of `vaddr`.
-    fn unmap(&mut self, _vaddr: VirtAddr) -> HalResult<()> {
-        unimplemented!();
-    }
-
-    /// Change the `flags` of the page of `vaddr`.
-    fn protect(&mut self, _vaddr: VirtAddr, _flags: MMUFlags) -> HalResult<()> {
-        unimplemented!();
-    }
-
-    /// Query the physical address which the page of `vaddr` maps to.
-    fn query(&mut self, _vaddr: VirtAddr) -> HalResult<PhysAddr> {
-        unimplemented!();
-    }
-
-    /// Get the physical address of root page table.
-    fn table_phys(&self) -> PhysAddr {
-        unimplemented!();
-    }
-
-    #[cfg(target_arch = "riscv64")]
-    /// Activate this page table
-    fn activate(&self) {
-        unimplemented!();
-    }
-}
diff --git a/kernel-hal/src/unimp/rand.rs b/kernel-hal/src/unimp/rand.rs
deleted file mode 100644
index 00528e89..00000000
--- a/kernel-hal/src/unimp/rand.rs
+++ /dev/null
@@ -1,18 +0,0 @@
-/// Fill random bytes to the buffer
-#[allow(unused_variables)]
-pub fn fill_random(buf: &mut [u8]) {
-    cfg_if::cfg_if! {
-        if #[cfg(target_arch = "x86_64")] {
-            // TODO: optimize
-            for x in buf.iter_mut() {
-                let mut r = 0;
-                unsafe {
-                    core::arch::x86_64::_rdrand16_step(&mut r);
-                }
-                *x = r as _;
-            }
-        } else {
-            unimplemented!()
-        }
-    }
-}
diff --git a/kernel-hal/src/unimp/serial.rs b/kernel-hal/src/unimp/serial.rs
deleted file mode 100644
index b009b66c..00000000
--- a/kernel-hal/src/unimp/serial.rs
+++ /dev/null
@@ -1,21 +0,0 @@
-use alloc::boxed::Box;
-
-/// Put a char by serial interrupt handler.
-pub fn serial_put(_x: u8) {
-    unimplemented!()
-}
-
-/// Register a callback of serial readable event.
-pub fn serial_set_callback(_callback: Box<dyn Fn() -> bool + Send + Sync>) {
-    unimplemented!()
-}
-
-/// Read a string from console.
-pub fn serial_read(_buf: &mut [u8]) -> usize {
-    unimplemented!()
-}
-
-/// Output a string to console.
-pub fn serial_write(_s: &str) {
-    unimplemented!()
-}
diff --git a/kernel-hal/src/unimp/thread.rs b/kernel-hal/src/unimp/thread.rs
deleted file mode 100644
index 3be76b86..00000000
--- a/kernel-hal/src/unimp/thread.rs
+++ /dev/null
@@ -1,18 +0,0 @@
-use alloc::boxed::Box;
-use core::future::Future;
-use core::pin::Pin;
-
-/// Spawn a new thread.
-pub fn spawn(_future: Pin<Box<dyn Future<Output = ()> + Send + 'static>>, _vmtoken: usize) {
-    unimplemented!()
-}
-
-/// Set tid and pid of current task.
-pub fn set_tid(_tid: u64, _pid: u64) {
-    unimplemented!()
-}
-
-/// Get tid and pid of current task.]
-pub fn get_tid() -> (u64, u64) {
-    unimplemented!()
-}
diff --git a/kernel-hal/src/unimp/timer.rs b/kernel-hal/src/unimp/timer.rs
deleted file mode 100644
index 07c4d5e6..00000000
--- a/kernel-hal/src/unimp/timer.rs
+++ /dev/null
@@ -1,21 +0,0 @@
-use alloc::boxed::Box;
-use core::time::Duration;
-
-/// Get current time.
-pub fn timer_now() -> Duration {
-    unimplemented!()
-}
-
-/// Set a new timer. After `deadline`, the `callback` will be called.
-pub fn timer_set(_deadline: Duration, _callback: Box<dyn FnOnce(Duration) + Send + Sync>) {
-    unimplemented!()
-}
-
-pub fn timer_set_next() {
-    unimplemented!()
-}
-
-/// Check timers, call when timer interrupt happened.
-pub fn timer_tick() {
-    unimplemented!()
-}
diff --git a/kernel-hal/src/unimp/vdso.rs b/kernel-hal/src/unimp/vdso.rs
deleted file mode 100644
index 112591ae..00000000
--- a/kernel-hal/src/unimp/vdso.rs
+++ /dev/null
@@ -1,5 +0,0 @@
-pub use crate::common::vdso::*;
-
-pub fn vdso_constants() -> VdsoConstants {
-    unimplemented!()
-}
diff --git a/linux-loader/src/lib.rs b/linux-loader/src/lib.rs
index a25f8572..2cb119cd 100644
--- a/linux-loader/src/lib.rs
+++ b/linux-loader/src/lib.rs
@@ -158,7 +158,7 @@ async fn new_thread(thread: CurrentThread) {
                     8 => handle_syscall(&thread, &mut cx).await,
                     // PageFault
                     12 | 13 | 15 => {
-                        let vaddr = kernel_hal::fetch_fault_vaddr();
+                        let vaddr = kernel_hal::context::fetch_fault_vaddr();
 
                         //注意这里flags没有包含WRITE权限，后面handle会移除写权限
                         let flags = if trap_num == 15 {
diff --git a/linux-object/src/fs/input/mice.rs b/linux-object/src/fs/input/mice.rs
index f16ef46d..0c3defdc 100644
--- a/linux-object/src/fs/input/mice.rs
+++ b/linux-object/src/fs/input/mice.rs
@@ -16,7 +16,7 @@ impl InputMiceInode {
     pub fn new() -> Self {
         let data = Arc::new(Mutex::new(VecDeque::with_capacity(MAX_QUEUE)));
         let data_clone = data.clone();
-        input::mice_set_callback(Box::new(move |data| {
+        input::mouse_set_callback(Box::new(move |data| {
             let mut queue = data_clone.lock();
             while queue.len() >= MAX_QUEUE {
                 queue.pop_front();
diff --git a/linux-object/src/fs/stdio.rs b/linux-object/src/fs/stdio.rs
index 8a3af366..a80c3316 100644
--- a/linux-object/src/fs/stdio.rs
+++ b/linux-object/src/fs/stdio.rs
@@ -132,7 +132,7 @@ 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::serial::serial_write(s);
+        kernel_hal::serial::print_str(s);
         Ok(buf.len())
     }
     fn poll(&self) -> Result<PollStatus> {
diff --git a/zCore/src/main.rs b/zCore/src/main.rs
index 87b7f7f4..4bea1bff 100644
--- a/zCore/src/main.rs
+++ b/zCore/src/main.rs
@@ -186,7 +186,7 @@ fn main(ramfs_data: &'static mut [u8], cmdline: &str) -> ! {
             let len = kernel_hal_bare::serial_read(&mut buffer);
             for c in &buffer[..len] {
                 STDIN.push((*c).into());
-                // kernel_hal_bare::serial_write(alloc::format!("{}", *c as char).as_str());
+                // kernel_hal_bare::print_str(alloc::format!("{}", *c as char).as_str());
             }
             false
         }
diff --git a/zircon-loader/src/lib.rs b/zircon-loader/src/lib.rs
index 880ed85e..7fe3a68c 100644
--- a/zircon-loader/src/lib.rs
+++ b/zircon-loader/src/lib.rs
@@ -241,7 +241,7 @@ async fn new_thread(thread: CurrentThread) {
                 if error_code & 0x10 != 0 {
                     flags.insert(MMUFlags::EXECUTE)
                 }
-                let fault_vaddr = kernel_hal::fetch_fault_vaddr();
+                let fault_vaddr = kernel_hal::context::fetch_fault_vaddr();
                 info!(
                     "page fault from user mode {:#x} {:#x?} {:?}",
                     fault_vaddr, error_code, flags
diff --git a/zircon-syscall/src/debug.rs b/zircon-syscall/src/debug.rs
index 941d81c0..990cd738 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::serial::serial_write(core::str::from_utf8(&data).unwrap());
+        kernel_hal::serial::print_str(core::str::from_utf8(&data).unwrap());
         Ok(())
     }
 
diff --git a/zircon-syscall/src/debuglog.rs b/zircon-syscall/src/debuglog.rs
index 2baa1833..97babaf3 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::serial::serial_write(&data);
+        kernel_hal::serial::print_str(&data);
         if data.as_bytes().last() != Some(&b'\n') {
-            kernel_hal::serial::serial_write("\n");
+            kernel_hal::serial::print_str("\n");
         }
         Ok(())
     }