kernel: use FLAGS_IF enum for 0x200 (#105)

kernel/syscall.go

@@ -415,7 +415,7 @@ func syscallInit() {
 	// write syscall selector
 	wrmsr(_MSR_STAR, 8<<32)
 	// clear IF when enter syscall
-	wrmsr(_MSR_FSTAR, 0x200)
+	wrmsr(_MSR_FSTAR, _FLAGS_IF)
 	// set syscall entry
 	wrmsr(_MSR_LSTAR, sys.FuncPC(syscallEntry))
 

kernel/thread.go

@@ -317,9 +317,9 @@ func pickup(pidx *int) *Thread {
 //go:nosplit
 func switchto(t *Thread) {
 	begin := nanosecond()
-	// assert interrupt is enableds
+	// assert that interrupt is enabled
 	// TODO: enable check
-	if t.tf != nil && t.tf.FLAGS&0x200 == 0 {
+	if t.tf != nil && t.tf.FLAGS&_FLAGS_IF == 0 {
 		throw("bad eflags")
 	}
 	setMythread(t)