diff --git a/README b/README
index 14ace83..8f3921a 100644
--- a/README
+++ b/README
@@ -13,3 +13,15 @@
 meson build/ && ninja -C build
 ```
 
+## Unit test
+
+* Run it in OpenBMC CI, refer to [local-ci-build.md][1]
+* Run it in [OE SDK][2], run below commands in a x86-64 SDK env:
+   ```
+   meson -Doe-sdk=enabled -Dtests=enabled build/
+   ninja -C build/ test  # Meson skips running the case due to it thinks it's cross compiling
+   ./build/test/utest  # Manually run the test
+   ```
+
+[1]: https://github.com/openbmc/docs/blob/master/local-ci-build.md
+[2]: https://github.com/openbmc/docs/blob/master/cheatsheet.md#building-the-openbmc-sdk
diff --git a/meson.build b/meson.build
index bc5e1b8..569eab9 100644
--- a/meson.build
+++ b/meson.build
@@ -15,4 +15,33 @@
                copy: true,
                install_dir: servicedir)
 
+# Common configurations for src and test
+cdata = configuration_data()
+cdata.set_quoted('VERSION_IFACE', 'xyz.openbmc_project.Software.Version')
+cdata.set_quoted('FILEPATH_IFACE', 'xyz.openbmc_project.Common.FilePath')
+cdata.set_quoted('BUSNAME_UPDATER', 'xyz.openbmc_project.Software.Psu.Updater')
+cdata.set_quoted('PSU_INVENTORY_IFACE', 'xyz.openbmc_project.Inventory.Item.PowerSupply')
+cdata.set_quoted('ACTIVATION_FWD_ASSOCIATION', 'inventory')
+cdata.set_quoted('ACTIVATION_REV_ASSOCIATION', 'activation')
+cdata.set_quoted('ACTIVE_FWD_ASSOCIATION', 'active')
+cdata.set_quoted('ACTIVE_REV_ASSOCIATION', 'software_version')
+cdata.set_quoted('FUNCTIONAL_FWD_ASSOCIATION', 'functional')
+cdata.set_quoted('FUNCTIONAL_REV_ASSOCIATION', 'software_version')
+
+cdata.set_quoted('SOFTWARE_OBJPATH', get_option('SOFTWARE_OBJPATH'))
+cdata.set_quoted('MANIFEST_FILE', get_option('MANIFEST_FILE'))
+cdata.set_quoted('PSU_INVENTORY_PATH_BASE', get_option('PSU_INVENTORY_PATH_BASE'))
+
+phosphor_dbus_interfaces = dependency('phosphor-dbus-interfaces')
+phosphor_logging = dependency('phosphor-logging')
+sdbusplus = dependency('sdbusplus')
+
+add_project_link_arguments(['-lstdc++fs'], language: 'cpp')
+
 subdir('src')
+
+build_tests = get_option('tests')
+
+if not build_tests.disabled()
+  subdir('test')
+endif
diff --git a/meson_options.txt b/meson_options.txt
index b878b69..e5297cf 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -1,3 +1,6 @@
+option('tests', type: 'feature', description: 'Build tests')
+option('oe-sdk', type: 'feature', description: 'Enable OE SDK')
+
 option('MANIFEST_FILE',
        type: 'string',
        value: 'MANIFEST',
@@ -8,7 +11,7 @@
        value: '/xyz/openbmc_project/software',
        description: 'The software manager Dbus root')
 
-option('PSU_INVENTORY_PATH',
+option('PSU_INVENTORY_PATH_BASE',
        type: 'string',
-       value: '/xyz/openbmc_project/inventory/system/chassis',
-       description: 'The PSU inventory path')
+       value: '/xyz/openbmc_project/inventory/system',
+       description: 'The base path for PSU inventory')
diff --git a/src/item_updater.cpp b/src/item_updater.cpp
index cfbadb0..b670735 100644
--- a/src/item_updater.cpp
+++ b/src/item_updater.cpp
@@ -92,7 +92,7 @@
 
         associations.emplace_back(std::make_tuple(ACTIVATION_FWD_ASSOCIATION,
                                                   ACTIVATION_REV_ASSOCIATION,
-                                                  PSU_INVENTORY_PATH));
+                                                  PSU_INVENTORY_PATH_BASE));
 
         fs::path manifestPath(filePath);
         manifestPath /= MANIFEST_FILE;
diff --git a/src/item_updater.hpp b/src/item_updater.hpp
index 96006f4..aacd77f 100644
--- a/src/item_updater.hpp
+++ b/src/item_updater.hpp
@@ -4,8 +4,10 @@
 
 #include "activation.hpp"
 #include "types.hpp"
+#include "utils.hpp"
 #include "version.hpp"
 
+#include <phosphor-logging/log.hpp>
 #include <sdbusplus/server.hpp>
 #include <xyz/openbmc_project/Association/Definitions/server.hpp>
 #include <xyz/openbmc_project/Collection/DeleteAll/server.hpp>
@@ -43,6 +45,13 @@
                      std::bind(std::mem_fn(&ItemUpdater::createActivation),
                                this, std::placeholders::_1))
     {
+        // TODO: create psu inventory objects based on the paths
+        using namespace phosphor::logging;
+        auto paths = utils::getPSUInventoryPath(bus);
+        for (const auto& p : paths)
+        {
+            log<level::INFO>("PSU path", entry("PATH=%s", p.c_str()));
+        }
     }
 
     /** @brief Deletes version
diff --git a/src/meson.build b/src/meson.build
index 95b1a5a..4e2e126 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -1,28 +1,7 @@
-phosphor_dbus_interfaces = dependency('phosphor-dbus-interfaces')
-phosphor_logging = dependency('phosphor-logging')
-sdbusplus = dependency('sdbusplus')
-
-add_project_link_arguments(['-lstdc++fs'], language: 'cpp')
-
-cdata = configuration_data()
-cdata.set_quoted('VERSION_IFACE', 'xyz.openbmc_project.Software.Version')
-cdata.set_quoted('FILEPATH_IFACE', 'xyz.openbmc_project.Common.FilePath')
-cdata.set_quoted('BUSNAME_UPDATER', 'xyz.openbmc_project.Software.Psu.Updater')
-cdata.set_quoted('ACTIVATION_FWD_ASSOCIATION', 'inventory')
-cdata.set_quoted('ACTIVATION_REV_ASSOCIATION', 'activation')
-cdata.set_quoted('ACTIVE_FWD_ASSOCIATION', 'active')
-cdata.set_quoted('ACTIVE_REV_ASSOCIATION', 'software_version')
-cdata.set_quoted('FUNCTIONAL_FWD_ASSOCIATION', 'functional')
-cdata.set_quoted('FUNCTIONAL_REV_ASSOCIATION', 'software_version')
-
-cdata.set_quoted('SOFTWARE_OBJPATH', get_option('SOFTWARE_OBJPATH'))
-cdata.set_quoted('MANIFEST_FILE', get_option('MANIFEST_FILE'))
-cdata.set_quoted('PSU_INVENTORY_PATH', get_option('PSU_INVENTORY_PATH'))
-
 configure_file(output: 'config.h',
   configuration: cdata,
 )
-configuration_inc = include_directories('.')
+psu_inc = include_directories('.')
 
 executable(
   'phosphor-psu-code-manager',
@@ -30,7 +9,8 @@
   'item_updater.cpp',
   'main.cpp',
   'version.cpp',
-  include_directories: configuration_inc,
+  'utils.cpp',
+  include_directories: psu_inc,
   dependencies: [
     phosphor_logging,
     phosphor_dbus_interfaces,
diff --git a/src/utils.cpp b/src/utils.cpp
new file mode 100644
index 0000000..deb5eee
--- /dev/null
+++ b/src/utils.cpp
@@ -0,0 +1,31 @@
+#include "config.h"
+
+#include "utils.hpp"
+
+#include <fstream>
+
+namespace utils
+{
+
+namespace // anonymous
+{
+constexpr auto MAPPER_BUSNAME = "xyz.openbmc_project.ObjectMapper";
+constexpr auto MAPPER_PATH = "/xyz/openbmc_project/object_mapper";
+constexpr auto MAPPER_INTERFACE = "xyz.openbmc_project.ObjectMapper";
+} // namespace
+
+std::vector<std::string> getPSUInventoryPath(sdbusplus::bus::bus& bus)
+{
+    std::vector<std::string> paths;
+    auto method = bus.new_method_call(MAPPER_BUSNAME, MAPPER_PATH,
+                                      MAPPER_INTERFACE, "GetSubTreePaths");
+    method.append(PSU_INVENTORY_PATH_BASE);
+    method.append(0); // Depth 0 to search all
+    method.append(std::vector<std::string>({PSU_INVENTORY_IFACE}));
+    auto reply = bus.call(method);
+
+    reply.read(paths);
+    return paths;
+}
+
+} // namespace utils
diff --git a/src/utils.hpp b/src/utils.hpp
new file mode 100644
index 0000000..5203509
--- /dev/null
+++ b/src/utils.hpp
@@ -0,0 +1,15 @@
+#pragma once
+
+#include <sdbusplus/bus.hpp>
+#include <string>
+#include <vector>
+
+namespace utils
+{
+
+/**
+ * @brief Get PSU inventory object path from DBus
+ */
+std::vector<std::string> getPSUInventoryPath(sdbusplus::bus::bus& bus);
+
+} // namespace utils
diff --git a/test/meson.build b/test/meson.build
new file mode 100644
index 0000000..4d644cf
--- /dev/null
+++ b/test/meson.build
@@ -0,0 +1,39 @@
+oe_sdk = get_option('oe-sdk')
+if oe_sdk.enabled()
+  # Setup OE SYSROOT
+  OECORE_TARGET_SYSROOT = run_command('sh', '-c', 'echo $OECORE_TARGET_SYSROOT').stdout().strip()
+  if OECORE_TARGET_SYSROOT == ''
+      error('Unable to get $OECORE_TARGET_SYSROOT, check your environment.')
+  endif
+  message('OE_SYSROOT: ' + OECORE_TARGET_SYSROOT)
+  rpath = ':'.join([OECORE_TARGET_SYSROOT + '/lib', OECORE_TARGET_SYSROOT + '/usr/lib'])
+  ld_so = run_command('sh', '-c', 'find ' + OECORE_TARGET_SYSROOT + '/lib/ld-*.so | sort -r -n | head -n1').stdout().strip()
+  dynamic_linker = ['-Wl,-dynamic-linker,' + ld_so]
+else
+  dynamic_linker = []
+endif
+
+gtest = dependency('gtest', main: true, disabler: true, required: build_tests)
+gmock = dependency('gmock', disabler: true, required: build_tests)
+
+configure_file(output: 'config.h',
+  configuration: cdata,
+)
+test_inc = include_directories('.')
+
+utest = executable(
+  'utest',
+  '../src/utils.cpp',
+  'test_utils.cpp',
+  include_directories: [psu_inc, test_inc],
+  link_args: dynamic_linker,
+  build_rpath: oe_sdk.enabled() ? rpath : '',
+  dependencies: [
+    gtest,
+    gmock,
+    phosphor_logging,
+    phosphor_dbus_interfaces,
+    sdbusplus,
+  ])
+
+test('all', utest)
diff --git a/test/test_utils.cpp b/test/test_utils.cpp
new file mode 100644
index 0000000..08eecf7
--- /dev/null
+++ b/test/test_utils.cpp
@@ -0,0 +1,62 @@
+#include "utils.hpp"
+
+#include <sdbusplus/test/sdbus_mock.hpp>
+
+#include <gmock/gmock.h>
+#include <gtest/gtest.h>
+
+using ::testing::_;
+using ::testing::Invoke;
+using ::testing::IsNull;
+using ::testing::Return;
+using ::testing::StrEq;
+
+TEST(Utils, GetPSUInventoryPath)
+{
+    sdbusplus::SdBusMock sdbusMock;
+    auto bus = sdbusplus::get_mocked_new(&sdbusMock);
+
+    EXPECT_CALL(sdbusMock, sd_bus_message_new_method_call(
+                               _, _, _, _, _, StrEq("GetSubTreePaths")));
+
+    EXPECT_CALL(sdbusMock, sd_bus_message_ref(IsNull()))
+        .WillOnce(Return(nullptr));
+    sdbusplus::message::message msg(nullptr, &sdbusMock);
+
+    const char* path0 = "/com/example/chassis/powersupply0";
+    const char* path1 = "/com/example/chassis/powersupply1";
+
+    // std::vector
+    EXPECT_CALL(sdbusMock,
+                sd_bus_message_enter_container(IsNull(), 'a', StrEq("s")))
+        .WillOnce(Return(1));
+
+    // while !at_end()
+    EXPECT_CALL(sdbusMock, sd_bus_message_at_end(IsNull(), 0))
+        .WillOnce(Return(0))
+        .WillOnce(Return(0))
+        .WillOnce(Return(1)); // So it exits the loop after reading two strings.
+
+    // std::string
+    EXPECT_CALL(sdbusMock, sd_bus_message_read_basic(IsNull(), 's', _))
+        .WillOnce(Invoke([&](sd_bus_message*, char, void* p) {
+            const char** s = static_cast<const char**>(p);
+            // Read the first parameter, the string.
+            *s = path0;
+            return 0;
+        }))
+        .WillOnce(Invoke([&](sd_bus_message*, char, void* p) {
+            const char** s = static_cast<const char**>(p);
+            // Read the first parameter, the string.
+            *s = path1;
+            return 0;
+        }));
+
+    EXPECT_CALL(sdbusMock, sd_bus_message_exit_container(IsNull()))
+        .WillOnce(Return(0)); /* end of std::vector */
+
+    auto ret = utils::getPSUInventoryPath(bus);
+    EXPECT_EQ(2u, ret.size());
+    EXPECT_EQ(path0, ret[0]);
+    EXPECT_EQ(path1, ret[1]);
+}