diff --git a/kernel/src/syscall/mem.rs b/kernel/src/syscall/mem.rs
new file mode 100644
index 0000000..71e8ad3
--- /dev/null
+++ b/kernel/src/syscall/mem.rs
@@ -0,0 +1,60 @@
+use rcore_memory::memory_set::handler::Delay;
+use rcore_memory::memory_set::MemoryAttr;
+
+use crate::memory::GlobalFrameAlloc;
+
+use super::*;
+
+pub fn sys_mmap(mut addr: usize, len: usize, prot: MmapProt, flags: MmapFlags, fd: i32, offset: usize) -> SysResult {
+    info!("mmap addr={:#x}, size={:#x}, prot={:?}, flags={:?}, fd={}, offset={:#x}", addr, len, prot, flags, fd, offset);
+    if addr == 0 {
+        // FIXME: choose an address to place
+        addr = 0x1000000;
+    }
+    if flags.contains(MmapFlags::ANONYMOUS) {
+        if flags.contains(MmapFlags::SHARED) {
+            return Err(SysError::Inval);
+        }
+        let mut proc = process();
+        let handler = Delay::new(prot_to_attr(prot), GlobalFrameAlloc);
+        proc.memory_set.push(addr, addr + len, handler, "mmap");
+        return Ok(addr as isize);
+    }
+    unimplemented!()
+}
+
+pub fn sys_munmap(addr: usize, len: usize) -> SysResult {
+    unimplemented!()
+}
+
+bitflags! {
+    pub struct MmapProt: usize {
+        /// Data cannot be accessed
+        const NONE = 0;
+        /// Data can be read
+        const READ = 1 << 0;
+        /// Data can be written
+        const WRITE = 1 << 1;
+        /// Data can be executed
+        const EXEC = 1 << 2;
+    }
+}
+
+bitflags! {
+    pub struct MmapFlags: usize {
+        /// Changes are shared.
+        const SHARED = 1 << 0;
+        /// Changes are private.
+        const PRIVATE = 1 << 1;
+        /// The mapping is not backed by any file. (non-POSIX)
+        const ANONYMOUS = 1 << 5;
+    }
+}
+
+fn prot_to_attr(prot: MmapProt) -> MemoryAttr {
+    let mut attr = MemoryAttr::default().user();
+    if prot.contains(MmapProt::EXEC) { attr = attr.execute(); }
+    if !prot.contains(MmapProt::WRITE) { attr = attr.readonly(); }
+    assert!(prot.contains(MmapProt::READ));
+    attr
+}
\ No newline at end of file
diff --git a/kernel/src/syscall/mod.rs b/kernel/src/syscall/mod.rs
index d3b0e8a..267d338 100644
--- a/kernel/src/syscall/mod.rs
+++ b/kernel/src/syscall/mod.rs
@@ -4,7 +4,7 @@ use alloc::{string::String, sync::Arc, vec::Vec};
 use core::{slice, str};
 
 use bitflags::bitflags;
-use rcore_fs::vfs::{Metadata, FileType, FsError, INode};
+use rcore_fs::vfs::{FileType, FsError, INode, Metadata};
 use spin::{Mutex, MutexGuard};
 
 use crate::arch::interrupt::TrapFrame;
@@ -14,10 +14,12 @@ use crate::thread;
 use crate::util;
 
 use self::fs::*;
+use self::mem::*;
 use self::proc::*;
 use self::time::*;
 
 mod fs;
+mod mem;
 mod proc;
 mod time;
 
@@ -33,9 +35,8 @@ pub fn syscall(id: usize, args: [usize; 6], tf: &mut TrapFrame) -> isize {
         005 => sys_fstat(args[0], args[1] as *mut Stat),
 //        007 => sys_poll(),
 //        008 => sys_lseek(),
-//        009 => sys_mmap(),
-//        011 => sys_munmap(),
-//        013 => sys_sigaction(),
+        009 => sys_mmap(args[0], args[1], MmapProt::from_bits_truncate(args[2]), MmapFlags::from_bits_truncate(args[3]), args[4] as i32, args[5]),
+        011 => sys_munmap(args[0], args[1]),
 //        019 => sys_readv(),
 //        020 => sys_writev(),
 //        021 => sys_access(),
@@ -85,6 +86,22 @@ pub fn syscall(id: usize, args: [usize; 6], tf: &mut TrapFrame) -> isize {
 //        293 => sys_pipe(),
 
         // for musl: empty impl
+        012 => {
+            warn!("sys_brk is unimplemented");
+            Ok(0)
+        }
+        013 => {
+            warn!("sys_sigaction is unimplemented");
+            Ok(0)
+        }
+        014 => {
+            warn!("sys_sigprocmask is unimplemented");
+            Ok(0)
+        }
+        131 => {
+            warn!("sys_sigaltstack is unimplemented");
+            Ok(0)
+        }
         158 => {
             warn!("sys_arch_prctl is unimplemented");
             Ok(0)