diff --git a/configs/board-bigtreetech_cb1_bookworm.conf b/configs/board-bigtreetech_cb1_bookworm.conf
new file mode 100644
index 0000000..b99e162
--- /dev/null
+++ b/configs/board-bigtreetech_cb1_bookworm.conf
@@ -0,0 +1,3 @@
+BOARD=bigtreetech-cb1
+RELEASE=bookworm
+BRANCH=legacy
diff --git a/configs/board-bigtreetech_cb1_bullseye.conf b/configs/board-bigtreetech_cb1_bullseye.conf
new file mode 100644
index 0000000..f71bd13
--- /dev/null
+++ b/configs/board-bigtreetech_cb1_bullseye.conf
@@ -0,0 +1,2 @@
+BOARD=bigtreetech-cb1
+BRANCH=legacy