Basic VM and other minor improvements.

Not complete, probably not fully debugged or optimized.

kernel/vm.h

@@ -0,0 +1,20 @@
+
+#ifndef _VM_H
+#define _VM_H 1
+
+#define CHECKRANGE_OR_SUSPEND(pr, start, length, wr)  { int mr; \
+	if(vm_running && (mr=vm_checkrange(proc_addr(who_p), pr, start, length, wr, 0)) != OK) { \
+		return mr;					 \
+	} }
+
+#define CHECKRANGE(pr, start, length, wr)   \
+	vm_checkrange(proc_addr(who_p), pr, start, length, wr, 1)
+
+/* Pseudo error code indicating a process request has to be
+ * restarted after an OK from VM.
+ */
+#define VMSUSPEND       -996
+
+#endif
+
+