Merge branch 'qemu_hpet_bug' into 'master'

Qemu hpet bug See merge request redox-os/kernel!210
2023-05-02 16:19:01 +00:00
parent 4bf307d88e d3a2fe7083
commit 37ba7c63b4
1 changed files with 9 additions and 1 deletions
@@ -14,7 +14,15 @@ pub fn counter() -> u128 {
        let comparator = unsafe { hpet.base_address.read_u64(hpet::T0_COMPARATOR_OFFSET) };
        // Get period in femtoseconds
        let capability = unsafe { hpet.base_address.read_u64(hpet::CAPABILITY_OFFSET) };
-        let period_fs = capability >> 32;
+
+        // There seems to be a bug in qemu on macos that causes the calculation to produce 0 for
+        // period_fs and hence a divide by zero calculating the divisor - workaround it while we
+        // try and get a fix from qemu: https://gitlab.com/qemu-project/qemu/-/issues/1570
+        let mut period_fs = capability >> 32;
+        if period_fs == 0 {
+            period_fs = 10_000_000;
+        }
+
        // Calculate divisor
        let divisor = (pit::RATE as u64 * 1_000_000) / period_fs;
        // Calculate last interrupt