From 253d1cfb9ba1c2381d55f05a4248b9e2bd827698 Mon Sep 17 00:00:00 2001
From: Florent Kermarrec <florent@enjoy-digital.fr>
Date: Mon, 26 Feb 2024 17:28:03 +0100
Subject: [PATCH] build/generic_platform/ConstraintManager: Add prepend
 parameter to add_extension.

In some cases, prepend is useful when we want to replace existing IOs.
---
 litex/build/generic_platform.py | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/litex/build/generic_platform.py b/litex/build/generic_platform.py
index 847435c81..24dda751d 100644
--- a/litex/build/generic_platform.py
+++ b/litex/build/generic_platform.py
@@ -205,8 +205,11 @@ class ConstraintManager:
         self.platform_commands = []
         self.connector_manager = ConnectorManager(connectors)
 
-    def add_extension(self, io):
-        self.available.extend(io)
+    def add_extension(self, io, prepend=False):
+        if prepend:
+            self.available = list(io) + self.available
+        else:
+            self.available.extend(io)
 
     def add_connector(self, connectors):
         self.connector_manager.add_connector(connectors)