From 07fc98b7c97dcb8f5affa83524a01621c6b15eb3 Mon Sep 17 00:00:00 2001
From: Yifan Wu <shinbokuow@163.com>
Date: Sun, 18 Jul 2021 19:21:16 +0800
Subject: [PATCH] Replace llvm_asm! with asm

---
 os/src/main.rs          |  2 +-
 os/src/mm/memory_set.rs |  2 +-
 os/src/sbi.rs           | 11 ++++++-----
 os/src/trap/mod.rs      | 11 ++++++++---
 user/src/lib.rs         |  2 +-
 user/src/syscall.rs     | 11 ++++++-----
 6 files changed, 23 insertions(+), 16 deletions(-)

diff --git a/os/src/main.rs b/os/src/main.rs
index 7879fc4e..14eb9542 100644
--- a/os/src/main.rs
+++ b/os/src/main.rs
@@ -1,7 +1,7 @@
 #![no_std]
 #![no_main]
 #![feature(global_asm)]
-#![feature(llvm_asm)]
+#![feature(asm)]
 #![feature(panic_info_message)]
 #![feature(alloc_error_handler)]
 
diff --git a/os/src/mm/memory_set.rs b/os/src/mm/memory_set.rs
index 079d6dba..f2311509 100644
--- a/os/src/mm/memory_set.rs
+++ b/os/src/mm/memory_set.rs
@@ -182,7 +182,7 @@ impl MemorySet {
         let satp = self.page_table.token();
         unsafe {
             satp::write(satp);
-            llvm_asm!("sfence.vma" :::: "volatile");
+            asm!("sfence.vma");
         }
     }
     pub fn translate(&self, vpn: VirtPageNum) -> Option<PageTableEntry> {
diff --git a/os/src/sbi.rs b/os/src/sbi.rs
index 36e15fcc..276c199d 100644
--- a/os/src/sbi.rs
+++ b/os/src/sbi.rs
@@ -14,11 +14,12 @@ const SBI_SHUTDOWN: usize = 8;
 fn sbi_call(which: usize, arg0: usize, arg1: usize, arg2: usize) -> usize {
     let mut ret;
     unsafe {
-        llvm_asm!("ecall"
-            : "={x10}" (ret)
-            : "{x10}" (arg0), "{x11}" (arg1), "{x12}" (arg2), "{x17}" (which)
-            : "memory"
-            : "volatile"
+        asm!(
+            "ecall",
+            inlateout("x10") arg0 => ret,
+            in("x11") arg1,
+            in("x12") arg2,
+            in("x17") which,
         );
     }
     ret
diff --git a/os/src/trap/mod.rs b/os/src/trap/mod.rs
index 674181aa..e6baba52 100644
--- a/os/src/trap/mod.rs
+++ b/os/src/trap/mod.rs
@@ -86,10 +86,15 @@ pub fn trap_return() -> ! {
     }
     let restore_va = __restore as usize - __alltraps as usize + TRAMPOLINE;
     unsafe {
-        llvm_asm!("fence.i" :::: "volatile");
-        llvm_asm!("jr $0" :: "r"(restore_va), "{a0}"(trap_cx_ptr), "{a1}"(user_satp) :: "volatile");
+        asm!(
+            "fence.i",
+            "jr {restore_va}",
+            restore_va = in(reg) restore_va,
+            in("a0") trap_cx_ptr,
+            in("a1") user_satp,
+            options(noreturn)
+        );
     }
-    panic!("Unreachable in back_to_user!");
 }
 
 #[no_mangle]
diff --git a/user/src/lib.rs b/user/src/lib.rs
index 122aefcf..1fae0fd2 100644
--- a/user/src/lib.rs
+++ b/user/src/lib.rs
@@ -1,5 +1,5 @@
 #![no_std]
-#![feature(llvm_asm)]
+#![feature(asm)]
 #![feature(linkage)]
 #![feature(panic_info_message)]
 
diff --git a/user/src/syscall.rs b/user/src/syscall.rs
index 1b23a48a..ed3d16aa 100644
--- a/user/src/syscall.rs
+++ b/user/src/syscall.rs
@@ -6,11 +6,12 @@ const SYSCALL_GET_TIME: usize = 169;
 fn syscall(id: usize, args: [usize; 3]) -> isize {
     let mut ret: isize;
     unsafe {
-        llvm_asm!("ecall"
-            : "={x10}" (ret)
-            : "{x10}" (args[0]), "{x11}" (args[1]), "{x12}" (args[2]), "{x17}" (id)
-            : "memory"
-            : "volatile"
+        asm!(
+            "ecall",
+            inlateout("x10") args[0] => ret,
+            in("x11") args[1],
+            in("x12") args[2],
+            in("x17") id
         );
     }
     ret