card_image: Implement system update commands in XCI

src/core/file_sys/card_image.cpp

@@ -172,6 +172,40 @@ u64 XCI::GetProgramTitleID() const {
     return secure_partition->GetProgramTitleID();
 }
 
+u32 XCI::GetSystemUpdateVersion() {
+    const auto update = GetPartition(XCIPartition::Update);
+    if (update == nullptr)
+        return 0;
+
+    for (const auto& file : update->GetFiles()) {
+        NCA nca{file, nullptr, 0, keys};
+
+        if (nca.GetStatus() != Loader::ResultStatus::Success)
+            continue;
+
+        if (nca.GetType() == NCAContentType::Meta && nca.GetTitleId() == 0x0100000000000816) {
+            const auto dir = nca.GetSubdirectories()[0];
+            const auto cnmt = dir->GetFile("SystemUpdate_0100000000000816.cnmt");
+            if (cnmt == nullptr)
+                continue;
+
+            CNMT cnmt_data{cnmt};
+
+            const auto metas = cnmt_data.GetMetaRecords();
+            if (metas.empty())
+                continue;
+
+            return metas[0].title_version;
+        }
+    }
+
+    return 0;
+}
+
+u64 XCI::GetSystemUpdateTitleID() const {
+    return 0x0100000000000816;
+}
+
 bool XCI::HasProgramNCA() const {
     return program != nullptr;
 }