diff --git a/tests/test_setup_env_helpers.py b/tests/test_setup_env_helpers.py
new file mode 100644
index 000000000..0eff2b87b
--- /dev/null
+++ b/tests/test_setup_env_helpers.py
@@ -0,0 +1,72 @@
+from types import SimpleNamespace
+
+import pytest
+
+import setup_env
+
+
+def test_system_info_normalizes_x86_alias(monkeypatch):
+    monkeypatch.setattr(setup_env.platform, "system", lambda: "Linux")
+    monkeypatch.setattr(setup_env.platform, "machine", lambda: "AMD64")
+
+    assert setup_env.system_info() == ("Linux", "x86_64")
+
+
+def test_system_info_normalizes_arm_alias(monkeypatch):
+    monkeypatch.setattr(setup_env.platform, "system", lambda: "Darwin")
+    monkeypatch.setattr(setup_env.platform, "machine", lambda: "aarch64")
+
+    assert setup_env.system_info() == ("Darwin", "arm64")
+
+
+def test_get_model_name_uses_supported_hf_repo(monkeypatch):
+    monkeypatch.setattr(
+        setup_env,
+        "args",
+        SimpleNamespace(
+            hf_repo="HF1BitLLM/Llama3-8B-1.58-100B-tokens",
+            model_dir="models/ignored",
+        ),
+        raising=False,
+    )
+
+    assert setup_env.get_model_name() == "Llama3-8B-1.58-100B-tokens"
+
+
+def test_get_model_name_uses_normalized_model_directory(monkeypatch):
+    monkeypatch.setattr(
+        setup_env,
+        "args",
+        SimpleNamespace(hf_repo=None, model_dir="models/local-bitnet/"),
+        raising=False,
+    )
+
+    assert setup_env.get_model_name() == "local-bitnet"
+
+
+def test_parse_args_accepts_arch_specific_quant_type(monkeypatch):
+    monkeypatch.setattr(setup_env.platform, "system", lambda: "Linux")
+    monkeypatch.setattr(setup_env.platform, "machine", lambda: "x86_64")
+    monkeypatch.setattr(
+        setup_env.sys,
+        "argv",
+        ["setup_env.py", "--model-dir", "models/local-bitnet", "--quant-type", "tl2"],
+    )
+
+    args = setup_env.parse_args()
+
+    assert args.model_dir == "models/local-bitnet"
+    assert args.quant_type == "tl2"
+
+
+def test_parse_args_rejects_quant_type_for_other_arch(monkeypatch):
+    monkeypatch.setattr(setup_env.platform, "system", lambda: "Darwin")
+    monkeypatch.setattr(setup_env.platform, "machine", lambda: "arm64")
+    monkeypatch.setattr(
+        setup_env.sys,
+        "argv",
+        ["setup_env.py", "--model-dir", "models/local-bitnet", "--quant-type", "tl2"],
+    )
+
+    with pytest.raises(SystemExit):
+        setup_env.parse_args()