[MOD] fix sbi_shutdown problem in Issue#127

os/src/panic.rs

@@ -1,6 +1,6 @@
 //! 代替 std 库，实现 panic 和 abort 的功能
 
-use crate::sbi::shutdown;
+use crate::sbi::sbi_hart_stop;
 use core::panic::PanicInfo;
 
 /// 打印 panic 的信息并 [`shutdown`]
@@ -23,7 +23,14 @@ fn panic_handler(info: &PanicInfo) -> ! {
     } else {
         println!("\x1b[1;31mpanic: '{}'\x1b[0m", info.message().unwrap());
     }
-    shutdown()
+
+    // This call is not expected to return under normal conditions.
+    // Returns SBI_ERR_FAILED through sbiret.error only if it fails, 
+    // where SBI_ERR_FAILED = -1.
+    let sbiret = sbi_hart_stop();
+    println!("sbiret.error = {}, sbiret.value = {}", sbiret.error, sbiret.value);
+
+    unreachable!()
 }
 
 /// 终止程序

os/src/sbi.rs

@@ -4,49 +4,64 @@
 
 /// SBI 调用
 #[inline(always)]
-fn sbi_call(which: usize, arg0: usize, arg1: usize, arg2: usize) -> usize {
-    let mut ret;
+fn sbi_call(eid: i32,fid: i32,  arg0: usize, arg1: usize, arg2: usize) -> Sbiret {
+    let mut error;
+    let mut value;
     unsafe {
         llvm_asm!("ecall"
-            : "={x10}" (ret)
-            : "{x10}" (arg0), "{x11}" (arg1), "{x12}" (arg2), "{x17}" (which)
+            : "={x10}" (error), "={x11}" (value)
+            : "{x10}" (arg0), "{x11}" (arg1), "{x12}" (arg2), "{x17}" (eid), "{x16}" (fid)
             : "memory"      // 如果汇编可能改变内存，则需要加入 memory 选项
             : "volatile"); // 防止编译器做激进的优化（如调换指令顺序等破坏 SBI 调用行为的优化）
     }
-    ret
+    Sbiret{error, value}
 }
 
-const SBI_SET_TIMER: usize = 0;
-const SBI_CONSOLE_PUTCHAR: usize = 1;
-const SBI_CONSOLE_GETCHAR: usize = 2;
-const SBI_CLEAR_IPI: usize = 3;
-const SBI_SEND_IPI: usize = 4;
-const SBI_REMOTE_FENCE_I: usize = 5;
-const SBI_REMOTE_SFENCE_VMA: usize = 6;
-const SBI_REMOTE_SFENCE_VMA_ASID: usize = 7;
-const SBI_SHUTDOWN: usize = 8;
+pub struct Sbiret {
+    pub error: i64,
+    pub value: i64,
+}
+
+const SBI_HSM_STOP_EID:i32 = 0x48534D;
+const SBI_HSM_STOP_FID:i32 = 1;
+
+const SBI_SET_TIMER: i32 = 0;
+const SBI_CONSOLE_PUTCHAR: i32 = 1;
+const SBI_CONSOLE_GETCHAR: i32 = 2;
+const SBI_CLEAR_IPI: i32 = 3;
+const SBI_SEND_IPI: i32 = 4;
+const SBI_REMOTE_FENCE_I: i32 = 5;
+const SBI_REMOTE_SFENCE_VMA: i32 = 6;
+const SBI_REMOTE_SFENCE_VMA_ASID: i32 = 7;
+const SBI_SHUTDOWN: i32 = 8;
 
 /// 向控制台输出一个字符
 ///
 /// 需要注意我们不能直接使用 Rust 中的 char 类型
 pub fn console_putchar(c: usize) {
-    sbi_call(SBI_CONSOLE_PUTCHAR, c, 0, 0);
+    sbi_call(SBI_CONSOLE_PUTCHAR, 0, c, 0, 0);
 }
 
 /// 从控制台中读取一个字符
 ///
 /// 没有读取到字符则返回 -1
-pub fn console_getchar() -> usize {
-    sbi_call(SBI_CONSOLE_GETCHAR, 0, 0, 0)
+pub fn console_getchar() -> Sbiret {
+    sbi_call(SBI_CONSOLE_GETCHAR, 0, 0, 0, 0)
 }
 
 /// 调用 SBI_SHUTDOWN 来关闭操作系统（直接退出 QEMU）
 pub fn shutdown() -> ! {
-    sbi_call(SBI_SHUTDOWN, 0, 0, 0);
+    sbi_call(SBI_SHUTDOWN, 0, 0, 0,0);
     unreachable!()
 }
 
 /// 设置下一次时钟中断的时间
 pub fn set_timer(time: usize) {
-    sbi_call(SBI_SET_TIMER, time, 0, 0);
+    sbi_call(SBI_SET_TIMER, 0, time, 0,0);
 }
+
+/// 关闭 hart ，等价于 SBI_SHUTDOWN ？
+/// TODO: need to verify
+pub fn sbi_hart_stop() -> Sbiret {
+    sbi_call(SBI_HSM_STOP_EID, SBI_HSM_STOP_FID, 0, 0, 0)
+}