Better user programs with a special std. Sleep and exit are calling scheduler instead of wfi.

crates/shared/src/syscall.rs

@@ -0,0 +1,106 @@
+use core::time::Duration;
+
+#[repr(u64)]
+pub enum SysCall {
+    Exit = 60,
+    NanoSleep = 101,
+    WriteIntTemp = 998,
+    WriteTemp = 999,
+    Unimplemented = 1 << 31,
+}
+
+impl From<u64> for SysCall {
+    fn from(value: u64) -> Self {
+        match value {
+            60 => SysCall::Exit,
+            101 => SysCall::NanoSleep,
+            998 => SysCall::WriteIntTemp,
+            999 => SysCall::WriteTemp,
+            _ => SysCall::Unimplemented,
+        }
+    }
+}
+
+#[allow(clippy::too_many_arguments)]
+unsafe fn _syscall(
+    syscall: SysCall,
+    mut a1: u64,
+    mut a2: u64,
+    mut a3: u64,
+    mut a4: u64,
+    mut a5: u64,
+    mut a6: u64,
+    mut a7: u64,
+) -> (u64, u64, u64, u64, u64, u64, u64, u64) {
+    let mut a0 = syscall as u64;
+    unsafe {
+        core::arch::asm!(
+            "ecall",
+            inlateout("a0") a0,
+            inlateout("a1") a1,
+            inlateout("a2") a2,
+            inlateout("a3") a3,
+            inlateout("a4") a4,
+            inlateout("a5") a5,
+            inlateout("a6") a6,
+            inlateout("a7") a7,
+            clobber_abi("system")
+        );
+    }
+    (a0, a1, a2, a3, a4, a5, a6, a7)
+}
+
+macro_rules! syscall {
+    ($syscall:expr, $a1:expr, $a2:expr, $a3:expr, $a4:expr, $a5:expr, $a6:expr, $a7:expr) => {
+        _syscall($syscall, $a1, $a2, $a3, $a4, $a5, $a6, $a7)
+    };
+    ($syscall:expr, $a1:expr, $a2:expr, $a3:expr, $a4:expr, $a5:expr, $a6:expr) => {
+        syscall!($syscall, $a1, $a2, $a3, $a4, $a5, $a6, 0)
+    };
+    ($syscall:expr, $a1:expr, $a2:expr, $a3:expr, $a4:expr, $a5:expr) => {
+        syscall!($syscall, $a1, $a2, $a3, $a4, $a5, 0)
+    };
+    ($syscall:expr, $a1:expr, $a2:expr, $a3:expr, $a4:expr) => {
+        syscall!($syscall, $a1, $a2, $a3, $a4, 0)
+    };
+    ($syscall:expr, $a1:expr, $a2:expr, $a3:expr) => {
+        syscall!($syscall, $a1, $a2, $a3, 0)
+    };
+    ($syscall:expr, $a1:expr, $a2:expr) => {
+        syscall!($syscall, $a1, $a2, 0)
+    };
+    ($syscall:expr, $a1:expr) => {
+        syscall!($syscall, $a1, 0)
+    };
+    ($syscall:expr) => {
+        syscall!($syscall, 0)
+    };
+}
+
+pub fn exit() {
+    unsafe {
+        syscall!(SysCall::Exit);
+    }
+}
+
+pub fn sleep(duration: Duration) {
+    unsafe {
+        let (duration_secs, duration_nanos) = (duration.as_secs(), duration.subsec_nanos() as u64);
+        syscall!(SysCall::NanoSleep, duration_secs, duration_nanos);
+    }
+}
+
+pub fn write_string_temp(content: &'static str) {
+    unsafe {
+        syscall!(
+            SysCall::WriteTemp,
+            content.as_ptr() as u64,
+            content.len() as u64
+        );
+    }
+}
+pub fn write_int_temp(content: u64) {
+    unsafe {
+        syscall!(SysCall::WriteIntTemp, content);
+    }
+}