diff --git a/src/core/process.c b/src/core/process.c
index c6660f22..4a705ef6 100644
--- a/src/core/process.c
+++ b/src/core/process.c
@@ -100,8 +100,12 @@ void step ( void ) {
 		ref_get ( process->refcnt ); /* Inhibit destruction mid-step */
 		desc = process->desc;
 		object = process_object ( process );
-		list_del ( &process->list );
-		list_add_tail ( &process->list, &run_queue );
+		if ( desc->reschedule ) {
+			list_del ( &process->list );
+			list_add_tail ( &process->list, &run_queue );
+		} else {
+			process_del ( process );
+		}
 		DBGC2 ( PROC_COL ( process ), "PROCESS " PROC_FMT
 			" executing\n", PROC_DBG ( process ) );
 		desc->step ( object );
diff --git a/src/include/ipxe/process.h b/src/include/ipxe/process.h
index f8b10a8a..9b757981 100644
--- a/src/include/ipxe/process.h
+++ b/src/include/ipxe/process.h
@@ -39,6 +39,8 @@ struct process_descriptor {
 	 * CPU to another process.
 	 */
 	void ( * step ) ( void *object );
+	/** Automatically reschedule the process */
+	int reschedule;
 };
 
 /**
@@ -78,6 +80,21 @@ struct process_descriptor {
 #define PROC_DESC( object_type, process, _step ) {			      \
 		.offset = process_offset ( object_type, process ),	      \
 		.step = PROC_STEP ( object_type, _step ),		      \
+		.reschedule = 1,					      \
+	}
+
+/**
+ * Define a process descriptor for a process that runs only once
+ *
+ * @v object_type	Containing object data type
+ * @v process		Process name (i.e. field within object data type)
+ * @v step		Process' step() method
+ * @ret desc		Object interface descriptor
+ */
+#define PROC_DESC_ONCE( object_type, process, _step ) {			      \
+		.offset = process_offset ( object_type, process ),	      \
+		.step = PROC_STEP ( object_type, _step ),		      \
+		.reschedule = 0,					      \
 	}
 
 /**
@@ -91,6 +108,7 @@ struct process_descriptor {
 #define PROC_DESC_PURE( _step ) {					      \
 		.offset = 0,						      \
 		.step = PROC_STEP ( struct process, _step ),		      \
+		.reschedule = 1,					      \
 	}
 
 extern void * __attribute__ (( pure ))