diff --git a/kernel/src/syscall.rs b/kernel/src/syscall.rs
index e2fde20..7985b86 100644
--- a/kernel/src/syscall.rs
+++ b/kernel/src/syscall.rs
@@ -10,10 +10,15 @@
 //! `sys_` then the name of the syscall. You can find functions like this in
 //! submodules, and you should also implement syscalls this way.
 
+const SYSCALL_READ: usize = 63;
 const SYSCALL_WRITE: usize = 64;
 const SYSCALL_EXIT: usize = 93;
 const SYSCALL_YIELD: usize = 124;
 const SYSCALL_GET_TIME: usize = 169;
+const SYSCALL_GETPID: usize = 172;
+const SYSCALL_FORK: usize = 220;
+const SYSCALL_EXEC: usize = 221;
+const SYSCALL_WAITPID: usize = 260;
 
 mod fs;
 mod process;
@@ -21,12 +26,19 @@ mod process;
 use fs::sys_write;
 use process::{sys_exit, sys_get_time, sys_yield};
 
+use crate::syscall::process::{sys_exec, sys_fork, sys_getpid, sys_read, sys_waitpid};
+
 pub fn syscall(syscall_id: usize, args: [usize; 3]) -> isize {
     match syscall_id {
+        SYSCALL_READ => sys_read(args[0], args[1] as *const u8, args[2]),
         SYSCALL_WRITE => sys_write(args[0], args[1] as *const u8, args[2]),
         SYSCALL_EXIT => sys_exit(args[0] as i32),
         SYSCALL_YIELD => sys_yield(),
         SYSCALL_GET_TIME => sys_get_time(),
+        SYSCALL_GETPID => sys_getpid(),
+        SYSCALL_FORK => sys_fork(),
+        SYSCALL_EXEC => sys_exec(args[0] as *const u8),
+        SYSCALL_WAITPID => sys_waitpid(args[0] as isize, args[1] as *mut i32),
         _ => panic!("Unsupported syscall_id: {}", syscall_id),
     }
 }
diff --git a/kernel/src/syscall/process.rs b/kernel/src/syscall/process.rs
index 464b98c..a7b01da 100644
--- a/kernel/src/syscall/process.rs
+++ b/kernel/src/syscall/process.rs
@@ -19,3 +19,23 @@ pub fn sys_yield() -> isize {
 pub fn sys_get_time() -> isize {
     get_time_ms() as isize
 }
+
+pub fn sys_fork() -> isize {
+    unimplemented!()
+}
+
+pub fn sys_waitpid(pid: isize, exit_code_ptr: *mut i32) -> isize {
+    unimplemented!()
+}
+
+pub fn sys_exec(path: *const u8) -> isize {
+    unimplemented!()
+}
+
+pub fn sys_getpid() -> isize {
+    unimplemented!()
+}
+
+pub fn sys_read(fd: usize, buf: *const u8, len: usize) -> isize {
+    unimplemented!()
+}
diff --git a/kernel/src/task/processor.rs b/kernel/src/task/processor.rs
new file mode 100644
index 0000000..e69de29
diff --git a/user_lib/src/syscall.rs b/user_lib/src/syscall.rs
index ef4b1a2..b88d924 100644
--- a/user_lib/src/syscall.rs
+++ b/user_lib/src/syscall.rs
@@ -1,9 +1,14 @@
 use core::arch::asm;
 
+const SYSCALL_READ: usize = 63;
 const SYSCALL_WRITE: usize = 64;
 const SYSCALL_EXIT: usize = 93;
-const SYSCALL_GET_TIME: usize = 169;
 const SYSCALL_YIELD: usize = 124;
+const SYSCALL_GET_TIME: usize = 169;
+const SYSCALL_GETPID: usize = 172;
+const SYSCALL_FORK: usize = 220;
+const SYSCALL_EXEC: usize = 221;
+const SYSCALL_WAITPID: usize = 260;
 
 fn syscall(id: usize, args: [usize; 3]) -> isize {
     let mut ret: isize;
@@ -19,6 +24,13 @@ fn syscall(id: usize, args: [usize; 3]) -> isize {
     ret
 }
 
+pub fn sys_read(fd: usize, buffer: &mut [u8]) -> isize {
+    syscall(
+        SYSCALL_READ,
+        [fd, buffer.as_mut_ptr() as usize, buffer.len()],
+    )
+}
+
 pub fn sys_write(fd: usize, buffer: &[u8]) -> isize {
     syscall(SYSCALL_WRITE, [fd, buffer.as_ptr() as usize, buffer.len()])
 }
@@ -34,3 +46,19 @@ pub fn sys_get_time() -> isize {
 pub fn sys_yield() -> isize {
     syscall(SYSCALL_YIELD, [0, 0, 0])
 }
+
+pub fn sys_getpid() -> isize {
+    syscall(SYSCALL_GETPID, [0, 0, 0])
+}
+
+pub fn sys_fork() -> isize {
+    syscall(SYSCALL_FORK, [0, 0, 0])
+}
+
+pub fn sys_exec(path: &str) -> isize {
+    syscall(SYSCALL_EXEC, [path.as_ptr() as usize, 0, 0])
+}
+
+pub fn sys_waitpid(pid: isize, exit_code: *mut i32) -> isize {
+    syscall(SYSCALL_WAITPID, [pid as usize, exit_code as usize, 0])
+}