test: Add test case for FIT image load address overlap detection

Add a new test case to verify that mkimage properly detects and reports
memory region overlaps in FIT image configurations.

The test creates a FIT image with kernel and FDT components that have
the same load address (0x40000), which should trigger the overlap
detection logic and cause mkimage to fail with an appropriate error
message.

Test verifies:
- mkimage returns non-zero exit code when overlap is detected
- Error message contains "Error: Overlap detected:"
- Error message identifies the specific overlapping components
  (kernel@1 and fdt@1)

This test ensures the overlap detection feature works correctly and
prevents deployment of FIT images with conflicting memory layouts
that could cause runtime failures.

Signed-off-by: Aristo Chen <aristo.chen@canonical.com>

diff --git a/test/py/tests/test_fit_mkimage_validate.py b/test/py/tests/test_fit_mkimage_validate.py
index 170b2a8..27299a5 100644 (file)
--- a/test/py/tests/test_fit_mkimage_validate.py
+++ b/test/py/tests/test_fit_mkimage_validate.py
@@ -103,3 +103,68 @@ def test_fit_invalid_default_config(ubman):
 
     assert result.returncode != 0, "mkimage should fail due to missing default config"
     assert re.search(r"Default configuration '.*' not found under /configurations", result.stderr)
+
+def test_fit_load_addr_overlap(ubman):
+    """Test that mkimage fails when load address overlap"""
+
+    its_fname = fit_util.make_fname(ubman, "invalid.its")
+    itb_fname = fit_util.make_fname(ubman, "invalid.itb")
+    kernel = fit_util.make_kernel(ubman, 'kernel.bin', 'kernel')
+    fdt = fit_util.make_dtb(ubman, '''
+/dts-v1/;
+/ {
+    model = "Test FDT";
+    compatible = "test";
+};
+''', 'test')
+
+    # Write ITS with an invalid reference to a nonexistent default config
+    its_text = '''
+/dts-v1/;
+
+/ {
+    images {
+        kernel@1 {
+            description = "Test Kernel";
+            data = /incbin/("kernel.bin");
+            type = "kernel";
+            arch = "sandbox";
+            os = "linux";
+            compression = "none";
+            load = <0x40000>;
+            entry = <0x40000>;
+        };
+        fdt@1 {
+            description = "Test FDT";
+            data = /incbin/("test.dtb");
+            type = "flat_dt";
+            arch = "sandbox";
+            os = "linux";
+            compression = "none";
+            load = <0x40000>;
+            entry = <0x40000>;
+        };
+    };
+
+    configurations {
+        default = "conf@1";
+        conf@1 {
+            kernel = "kernel@1";
+            fdt = "fdt@1";
+        };
+    };
+};
+'''
+
+    with open(its_fname, 'w') as f:
+        f.write(its_text)
+
+    mkimage = os.path.join(ubman.config.build_dir, 'tools/mkimage')
+    cmd = [mkimage, '-f', its_fname, itb_fname]
+
+    result = subprocess.run(cmd, capture_output=True, text=True)
+
+    assert result.returncode != 0, "mkimage should fail due to memory overlap"
+    assert "Error: Overlap detected:" in result.stderr
+    # Check that it identifies the specific overlapping components
+    assert "kernel@1" in result.stderr and "fdt@1" in result.stderr