ptos/amd64: thread: Add HalThreadYield()

Signed-off-by: Chloe M <chloe@mensia.org>

service/ptos/arch/amd64/ps/thread.c

@@ -145,6 +145,12 @@ HalThreadInit(THREAD *Thread, ULONG Flags, UPTR Ip)
     return STATUS_SUCCESS;
 }
 
+VOID
+HalThreadYield(VOID)
+{
+    asm volatile("int $0x81");
+}
+
 VOID
 HalPrimeThreadTimer(ULONG Usec)
 {

service/ptos/head/hal/thread.h

@@ -22,6 +22,11 @@
  */
 PT_STATUS HalThreadInit(THREAD *Thread, ULONG Flags, UPTR Ip);
 
+/*
+ * Yield the current thread
+ */
+VOID HalThreadYield(VOID);
+
 /*
  * Prime the scheduler timer
  *