commit bb9c622d16d8bf6f2f6f98551d19ebd75e20a5ed
author Gobinath Krishnamoorthy <gobinathk@google.com> Thu Nov 03 20:08:01 2022 +0000
committer Zhikui Ren <zhikui.ren@intel.com> Sun Nov 13 17:26:47 2022 +0000
tree 06bc59a54901790d8788bbb28cf4189aea1669f2
parent 744b35aad0051084c7b71fee8898d1e496345270

Use mobo's object system iface to find mobo path.

This change use system interface to find the inventory object path
of the root board in the system. This replaces the `ReScan`
method to get the root object path. The `ReScan` implementation in
EntityManager never upstreamed and that CL was abandoned.
CL: https://gerrit.openbmc.org/c/openbmc/entity-manager/+/46128

TESTED:

busctl get-property xyz.openbmc_project.Smbios.MDR_V2 \
> /xyz/openbmc_project/inventory/system/chassis/motherboard/cpu0 \
> xyz.openbmc_project.Association.Definitions Associations
a(sss) 1 "chassis" "processors" "/xyz/openbmc_project/inventory/system/board/motherboard"

busctl get-property xyz.openbmc_project.Smbios.MDR_V2 \
> /xyz/openbmc_project/inventory/system/chassis/motherboard/cpu1 \
> xyz.openbmc_project.Association.Definitions Associations
a(sss) 1 "chassis" "processors" "/xyz/openbmc_project/inventory/system/board/motherboard"

busctl  --verbose get-property xyz.openbmc_project.ObjectMapper \
/xyz/openbmc_project/inventory/system/board/motherboard/processors \
xyz.openbmc_project.Association endpoints
ARRAY "s" {
        STRING "/xyz/openbmc_project/inventory/system/chassis/motherboard/cpu0";
        STRING "/xyz/openbmc_project/inventory/system/chassis/motherboard/cpu1";
};

Signed-off-by: Gobinath Krishnamoorthy <gobinathk@google.com>
Change-Id: Idc6f8c58324c7618a2c4c5a2c4079599c7c29cf4

include/mdrv2.hpp

diff --git a/include/mdrv2.hpp b/include/mdrv2.hpp
index ddde0ef..994598c 100644
--- a/include/mdrv2.hpp
+++ b/include/mdrv2.hpp
@@ -49,6 +49,14 @@
 static constexpr const char* smbiosPath = "/xyz/openbmc_project/Smbios";
 static constexpr const char* smbiosInterfaceName =
     "xyz.openbmc_project.Smbios.GetRecordType";
+static constexpr const char* mapperBusName = "xyz.openbmc_project.ObjectMapper";
+static constexpr const char* mapperPath = "/xyz/openbmc_project/object_mapper";
+static constexpr const char* mapperInterface =
+    "xyz.openbmc_project.ObjectMapper";
+static constexpr const char* systemInterfacePath =
+    "/xyz/openbmc_project/inventory/system";
+static constexpr const char* systemInterface =
+    "xyz.openbmc_project.Inventory.Item.System";
 constexpr const int limitEntryLen = 0xff;
 
 class MDR_V2 :

src/mdrv2.cpp

diff --git a/src/mdrv2.cpp b/src/mdrv2.cpp
index 3949630..f8e2654 100644
--- a/src/mdrv2.cpp
+++ b/src/mdrv2.cpp
@@ -395,14 +395,25 @@
 void MDR_V2::systemInfoUpdate()
 {
     std::string motherboardPath;
-    sdbusplus::message_t method =
-        bus.new_method_call("xyz.openbmc_project.EntityManager",
-                            "/xyz/openbmc_project/EntityManager",
-                            "xyz.openbmc_project.EntityManager", "ReScan");
+    auto method = bus.new_method_call(mapperBusName, mapperPath,
+                                      mapperInterface, "GetSubTreePaths");
+    method.append(systemInterfacePath);
+    method.append(0);
+    method.append(std::vector<std::string>({systemInterface}));
     try
     {
+        std::vector<std::string> paths;
         sdbusplus::message_t reply = bus.call(method);
-        reply.read(motherboardPath);
+        reply.read(paths);
+        if (paths.size() < 1)
+        {
+            phosphor::logging::log<phosphor::logging::level::ERR>(
+                "Failed to get system motherboard dbus path.");
+        }
+        else
+        {
+            motherboardPath = std::move(paths[0]);
+        }
     }
     catch (const sdbusplus::exception_t& e)
     {