diff --git a/Cargo.toml b/Cargo.toml
index 824e767..2c9cb59 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -3,9 +3,9 @@ members = [
     "xuantie-riscv",
     "xuantie-riscv-rt",
 ]
-resolver = "3"
+resolver = "2"
 
 [workspace.package]
-edition = "2024"
+edition = "2021"
 license = "MulanPSL-2.0"
 repository = "https://github.com/rustsbi/xuantie"
diff --git a/xuantie-riscv/src/lib.rs b/xuantie-riscv/src/lib.rs
index 21ace63..0add75d 100644
--- a/xuantie-riscv/src/lib.rs
+++ b/xuantie-riscv/src/lib.rs
@@ -70,4 +70,6 @@ pub mod asm;
 pub mod debug;
 pub mod paging;
 pub mod peripheral;
+
+#[rustfmt::skip]
 pub mod register;