implement monotonic for aarch64

2025-05-13 15:30:45 +08:00
parent 407c0c1403
commit f5aeb0b43a
1 changed files with 8 additions and 1 deletions
@@ -1,4 +1,11 @@
+use crate::time::NANOS_PER_SEC;
+
 pub fn monotonic_absolute() -> u128 {
    //TODO: aarch64 generic timer counter
-    *crate::time::OFFSET.lock()
+    let ticks: usize;
+    unsafe { core::arch::asm!("mrs {}, cntpct_el0", out(reg) ticks) };
+    let freq: usize;
+    unsafe { core::arch::asm!("mrs {}, cntfrq_el0", out(reg) freq) };
+
+    ticks as u128 * NANOS_PER_SEC / freq as u128
 }