diff --git a/am-kernels b/am-kernels
deleted file mode 160000
index 8c4ea04..0000000
--- a/am-kernels
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit 8c4ea046225e2dce599dc36aeef6c4c857996d00
diff --git a/diffu b/diffu
deleted file mode 160000
index 645b0f6..0000000
--- a/diffu
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit 645b0f607ae510fda4d71b8152ea932a2b38bc32
diff --git a/flake.nix b/flake.nix
index 5c9c6f7..61fa944 100644
--- a/flake.nix
+++ b/flake.nix
@@ -11,6 +11,8 @@
       url = "git+https://git.xinyang.life/xin/nur.git";
       inputs.nixpkgs.follows = "nixpkgs";
     };
+    # diffu.url = "github:xinyangli/diffu";
+    # am-kernels.url = "git+https://git.xinyang.life/xin/am-kernels.git";
   };
 
   outputs = { self, flake-utils, nixpkgs, nixpkgs-circt162, pre-commit-hooks, nur-xin }@inputs:
@@ -65,13 +67,9 @@
           abstract-machine = pkgs.callPackage ./abstract-machine { isa = "native"; };
           nemu = pkgs.callPackage ./nemu { };
           nemu-lib = pkgs.callPackage ./nemu { };
-          am-kernels = pkgs.callPackage ./am-kernels { abstract-machine = abstract-machine; arch = "native"; };
 
           rv32Cross = rec {
             abstract-machine = rv32CrossConfig.callPackage ./abstract-machine { isa = "riscv"; platform = [ "nemu" "npc" ]; };
-            am-kernels-npc = rv32CrossConfig.callPackage ./am-kernels { inherit abstract-machine; arch = "riscv-npc"; };
-            am-kernels-nemu = rv32CrossConfig.callPackage ./am-kernels { inherit abstract-machine; arch = "riscv-nemu"; };
-            am-kernels = rv32CrossConfig.callPackage ./am-kernels { abstract-machine = abstract-machine; arch = "riscv"; };
           };
         };
 
@@ -94,13 +92,13 @@
             self.packages.${system}.nemu
           ];
           NEMU_HOME = "/home/xin/repo/ysyx-workbench/nemu";
-          NEMU_IMAGES_PATH = self.packages.${system}.rv32Cross.am-kernels-nemu + "/share/am-kernels";
+          # NEMU_IMAGES_PATH = self.packages.${system}.rv32Cross.am-kernels-nemu + "/share/am-kernels";
         };
 
         devShells.npc = pkgs.mkShell.override { stdenv = pkgs.ccacheStdenv; } {
           inherit (self.checks.${system}.pre-commit-check) shellHook;
           CHISEL_FIRTOOL_PATH = "${nixpkgs-circt162.legacyPackages.${system}.circt}/bin";
-          NPC_IMAGES_PATH = "${self.packages.${system}.rv32Cross.am-kernels-npc}/share/am-kernels";
+          # NPC_IMAGES_PATH = "${self.packages.${system}.rv32Cross.am-kernels-npc}/share/am-kernels";
           packages = with pkgs; [
             clang-tools
             cmake
@@ -125,7 +123,6 @@
             flex
             bison
             verilator
-            self.packages.${system}.rv32Cross.am-kernels-npc
           ];
 
           buildInputs = with pkgs; [