diff --git a/lib/arch.py b/lib/arch.py
index 9f73c67..c3702ce 100644
--- a/lib/arch.py
+++ b/lib/arch.py
@@ -3,7 +3,18 @@ import os
 from . import packie
 
 all: dict[str, dict[str, str]] = {
-    "aarch64-semios-linux": {},
+    "aarch64-semios-linux": {
+        "CC": "clang -target aarch64-semios-linux-musl",
+        "CXX": "clang++ -target aarch64-semios-linux-musl",
+    },
+    "x86_64-semios-linux": {
+        "CC": "clang -target x86_64-semios-linux-musl",
+        "CXX": "clang++ -target x86_64-semios-linux-musl",
+    },
+    "riscv64-semios-linux": {
+        "CC": "clang -target riscv64-semios-linux-musl",
+        "CXX": "clang++ -target riscv64-semios-linux-musl",
+    },
 }
 _target: str = packie.host_arch()
 
@@ -15,5 +26,5 @@ def get_target():
 def set_target(arch: str):
     global _target
     _target = arch
-    for key, val in all[_target]:
-        os.environ[key] = val
+    for key in all[_target].keys():
+        os.environ[key] = all[_target][key]
diff --git a/x.py b/x.py
index f31424a..b3af438 100644
--- a/x.py
+++ b/x.py
@@ -20,8 +20,13 @@ argparser = argparse.ArgumentParser(
 argparser.add_argument(
     "--target", type=str, help="Target architecture to build the package for"
 )
-argparser.add_argument("--build", type=str, help="Package to build")
-argparser.add_argument("--clean", type=str, help="Package to clean")
+subparsers = argparser.add_subparsers(dest="subcommand")
+parser_build = subparsers.add_parser("build")
+parser_build.add_argument("BUILD_PKGNAME")
+parser_clean = subparsers.add_parser("clean")
+parser_clean.add_argument("CLEAN_PKGNAME")
+parser_list = subparsers.add_parser("list")
+parser_list.add_argument("ITEM", choices=("all", "built", "new"))
 args = argparser.parse_args()
 
 if args.target:
@@ -105,6 +110,10 @@ def run_build_package(package: str):
         composer.write_manifest(manifest)
         composer.compose()
 
+    # Build success
+    with open(f"{package_dir}/target/build-ok.tag", "wt+") as file:
+        file.write("OK")
+
 
 def run_clean_package(package: str):
     try:
@@ -113,7 +122,37 @@ def run_clean_package(package: str):
         pass
 
 
-if args.build:
-    run_build_package(args.build)
-if args.clean:
-    run_clean_package(args.clean)
+def run_list(item):
+    if item == "all":
+        for i in os.listdir("packages"):
+            if i.startswith("."):
+                continue
+            print(i)
+    elif item == "built":
+        for i in os.listdir("packages"):
+            if i.startswith("."):
+                continue
+            if os.path.exists(f"packages/{i}/target/build-ok.tag"):
+                print(i)
+    elif item == "new":
+        for i in os.listdir("packages"):
+            if i.startswith("."):
+                continue
+            try:
+                pkgbuild_mtime = os.path.getmtime(f"packages/{i}/pkgbuild.py")
+                target_mtime = os.path.getmtime(f"packages/{i}/target/build-ok.tag")
+                if target_mtime < pkgbuild_mtime:
+                    print(i)
+            except Exception:
+                print(i)
+
+
+if args.subcommand == "build":
+    run_build_package(args.BUILD_PKGNAME)
+elif args.subcommand == "clean":
+    run_clean_package(args.CLEAN_PKGNAME)
+elif args.subcommand == "list":
+    run_list(args.ITEM)
+else:
+    print("error: no action specified", file=sys.stderr)
+    exit(1)