[PATCH v1 5/5] test: Add test case for FIT image load address overlap detection

[Aristo Chen]

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 at 1 and fdt at 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 at canonical.com>
---
 test/py/tests/test_fit_mkimage_validate.py | 65 ++++++++++++++++++++++
 1 file changed, 65 insertions(+)

diff --git a/test/py/tests/test_fit_mkimage_validate.py b/test/py/tests/test_fit_mkimage_validate.py
index ef974c8c762..51f7f64b257 100644
--- a/test/py/tests/test_fit_mkimage_validate.py
+++ b/test/py/tests/test_fit_mkimage_validate.py
@@ -101,3 +101,68 @@ 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 at 1 {
+            description = "Test Kernel";
+            data = /incbin/("kernel.bin");
+            type = "kernel";
+            arch = "sandbox";
+            os = "linux";
+            compression = "none";
+            load = <0x40000>;
+            entry = <0x40000>;
+        };
+        fdt at 1 {
+            description = "Test FDT";
+            data = /incbin/("test.dtb");
+            type = "flat_dt";
+            arch = "sandbox";
+            os = "linux";
+            compression = "none";
+            load = <0x40000>;
+            entry = <0x40000>;
+        };
+    };
+
+    configurations {
+        default = "conf at 1";
+        conf at 1 {
+            kernel = "kernel at 1";
+            fdt = "fdt at 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 at 1" in result.stderr and "fdt at 1" in result.stderr
-- 
2.43.0