完成与Linux兼容的Ntty (#517)

* 已经完成的功能：
- 写：printf能够正常在tty输出
- 读：与键盘驱动接上
- 信号： 能够正常通过ctrl向前台进程发送信号

* 支持目前的shell，改动printk使其与新版tty兼容。

* 删除原有tty文件夹，并更改新tty文件名

* 添加clear清屏程序

* 实现tty部分ioctl，更改部分问题

kernel/src/syscall/mod.rs

@@ -12,6 +12,7 @@ use crate::{
     process::{
         fork::KernelCloneArgs,
         resource::{RLimit64, RUsage},
+        ProcessManager,
     },
 };
 
@@ -853,6 +854,11 @@ impl Syscall {
                 Ok(0)
             }
 
+            SYS_SETPGID => {
+                kwarn!("SYS_SETPGID has not yet been implemented");
+                Ok(0)
+            }
+
             SYS_RT_SIGPROCMASK => {
                 kwarn!("SYS_RT_SIGPROCMASK has not yet been implemented");
                 Ok(0)
@@ -1009,6 +1015,19 @@ impl Syscall {
                 Err(SystemError::ENOSYS)
             }
 
+            #[cfg(target_arch = "x86_64")]
+            SYS_GETRLIMIT => {
+                let resource = args[0];
+                let rlimit = args[1] as *mut RLimit64;
+
+                Self::prlimit64(
+                    ProcessManager::current_pcb().pid(),
+                    resource,
+                    0 as *const RLimit64,
+                    rlimit,
+                )
+            }
+
             SYS_SCHED_YIELD => Self::sched_yield(),
 
             _ => panic!("Unsupported syscall ID: {}", syscall_num),