10 files changed, 20 insertions, 40 deletions

diff --git a/src/core/loader/loader.cpp b/src/core/loader/loader.cpp
index f24474ed8..07c65dc1a 100644
--- a/src/core/loader/loader.cpp
+++ b/src/core/loader/loader.cpp
@@ -135,7 +135,7 @@ constexpr std::array<const char*, 66> RESULT_MESSAGES{
     "The titlekey and/or titlekek is incorrect or the section header is invalid.",
     "The XCI file is missing a Program-type NCA.",
     "The NCA file is not an application.",
-    "The ExeFS partition could not be found.",
+    "The Program-type NCA contains no executable. An update may be required.",
     "The XCI file has a bad header.",
     "The XCI file is missing a partition.",
     "The file could not be found or does not exist.",
@@ -169,7 +169,7 @@ constexpr std::array<const char*, 66> RESULT_MESSAGES{
     "The BKTR-type NCA has a bad Subsection block.",
     "The BKTR-type NCA has a bad Relocation bucket.",
     "The BKTR-type NCA has a bad Subsection bucket.",
-    "The BKTR-type NCA is missing the base RomFS.",
+    "Game updates cannot be loaded directly. Load the base game instead.",
     "The NSP or XCI does not contain an update in addition to the base game.",
     "The KIP file has a bad header.",
     "The KIP BLZ decompression of the section failed unexpectedly.",
diff --git a/src/core/loader/loader.h b/src/core/loader/loader.h
index 7a2a52fd4..721eb8e8c 100644
--- a/src/core/loader/loader.h
+++ b/src/core/loader/loader.h
@@ -79,8 +79,6 @@ enum class ResultStatus : u16 {
     ErrorBadPFSHeader,
     ErrorIncorrectPFSFileSize,
     ErrorBadNCAHeader,
-    ErrorCompressedNCA,
-    ErrorSparseNCA,
     ErrorMissingProductionKeyFile,
     ErrorMissingHeaderKey,
     ErrorIncorrectHeaderKey,
@@ -276,16 +274,6 @@ public:
     }
 
     /**
-     * Gets the difference between the start of the IVFC header and the start of level 6 (RomFS)
-     * data. Needed for BKTR patching.
-     *
-     * @return IVFC offset for RomFS.
-     */
-    virtual u64 ReadRomFSIVFCOffset() const {
-        return 0;
-    }
-
-    /**
      * Get the title of the application
      *
      * @param[out] title Reference to store the application title into
diff --git a/src/core/loader/nax.cpp b/src/core/loader/nax.cpp
index cf35b1249..3b7b005ff 100644
--- a/src/core/loader/nax.cpp
+++ b/src/core/loader/nax.cpp
@@ -76,10 +76,6 @@ ResultStatus AppLoader_NAX::ReadRomFS(FileSys::VirtualFile& dir) {
     return nca_loader->ReadRomFS(dir);
 }
 
-u64 AppLoader_NAX::ReadRomFSIVFCOffset() const {
-    return nca_loader->ReadRomFSIVFCOffset();
-}
-
 ResultStatus AppLoader_NAX::ReadProgramId(u64& out_program_id) {
     return nca_loader->ReadProgramId(out_program_id);
 }
diff --git a/src/core/loader/nax.h b/src/core/loader/nax.h
index d7f70db43..81df2bbcd 100644
--- a/src/core/loader/nax.h
+++ b/src/core/loader/nax.h
@@ -39,7 +39,6 @@ public:
     LoadResult Load(Kernel::KProcess& process, Core::System& system) override;
 
     ResultStatus ReadRomFS(FileSys::VirtualFile& dir) override;
-    u64 ReadRomFSIVFCOffset() const override;
     ResultStatus ReadProgramId(u64& out_program_id) override;
 
     ResultStatus ReadBanner(std::vector<u8>& buffer) override;
diff --git a/src/core/loader/nca.cpp b/src/core/loader/nca.cpp
index 513af194d..09d40e695 100644
--- a/src/core/loader/nca.cpp
+++ b/src/core/loader/nca.cpp
@@ -5,6 +5,8 @@
 
 #include "core/core.h"
 #include "core/file_sys/content_archive.h"
+#include "core/file_sys/nca_metadata.h"
+#include "core/file_sys/registered_cache.h"
 #include "core/file_sys/romfs_factory.h"
 #include "core/hle/kernel/k_process.h"
 #include "core/hle/service/filesystem/filesystem.h"
@@ -43,9 +45,23 @@ AppLoader_NCA::LoadResult AppLoader_NCA::Load(Kernel::KProcess& process, Core::S
         return {ResultStatus::ErrorNCANotProgram, {}};
     }
 
-    const auto exefs = nca->GetExeFS();
+    auto exefs = nca->GetExeFS();
     if (exefs == nullptr) {
-        return {ResultStatus::ErrorNoExeFS, {}};
+        LOG_INFO(Loader, "No ExeFS found in NCA, looking for ExeFS from update");
+
+        // This NCA may be a sparse base of an installed title.
+        // Try to fetch the ExeFS from the installed update.
+        const auto& installed = system.GetContentProvider();
+        const auto update_nca = installed.GetEntry(FileSys::GetUpdateTitleID(nca->GetTitleId()),
+                                                   FileSys::ContentRecordType::Program);
+
+        if (update_nca) {
+            exefs = update_nca->GetExeFS();
+        }
+
+        if (exefs == nullptr) {
+            return {ResultStatus::ErrorNoExeFS, {}};
+        }
     }
 
     directory_loader = std::make_unique<AppLoader_DeconstructedRomDirectory>(exefs, true);
@@ -77,14 +93,6 @@ ResultStatus AppLoader_NCA::ReadRomFS(FileSys::VirtualFile& dir) {
     return ResultStatus::Success;
 }
 
-u64 AppLoader_NCA::ReadRomFSIVFCOffset() const {
-    if (nca == nullptr) {
-        return 0;
-    }
-
-    return nca->GetBaseIVFCOffset();
-}
-
 ResultStatus AppLoader_NCA::ReadProgramId(u64& out_program_id) {
     if (nca == nullptr || nca->GetStatus() != ResultStatus::Success) {
         return ResultStatus::ErrorNotInitialized;
diff --git a/src/core/loader/nca.h b/src/core/loader/nca.h
index d22d9146e..cf356ce63 100644
--- a/src/core/loader/nca.h
+++ b/src/core/loader/nca.h
@@ -40,7 +40,6 @@ public:
     LoadResult Load(Kernel::KProcess& process, Core::System& system) override;
 
     ResultStatus ReadRomFS(FileSys::VirtualFile& dir) override;
-    u64 ReadRomFSIVFCOffset() const override;
     ResultStatus ReadProgramId(u64& out_program_id) override;
 
     ResultStatus ReadBanner(std::vector<u8>& buffer) override;
diff --git a/src/core/loader/nsp.cpp b/src/core/loader/nsp.cpp
index 80663e0e0..f9b2549a3 100644
--- a/src/core/loader/nsp.cpp
+++ b/src/core/loader/nsp.cpp
@@ -121,10 +121,6 @@ ResultStatus AppLoader_NSP::ReadRomFS(FileSys::VirtualFile& out_file) {
     return secondary_loader->ReadRomFS(out_file);
 }
 
-u64 AppLoader_NSP::ReadRomFSIVFCOffset() const {
-    return secondary_loader->ReadRomFSIVFCOffset();
-}
-
 ResultStatus AppLoader_NSP::ReadUpdateRaw(FileSys::VirtualFile& out_file) {
     if (nsp->IsExtractedType()) {
         return ResultStatus::ErrorNoPackedUpdate;
diff --git a/src/core/loader/nsp.h b/src/core/loader/nsp.h
index 003cc345c..79df4586a 100644
--- a/src/core/loader/nsp.h
+++ b/src/core/loader/nsp.h
@@ -46,7 +46,6 @@ public:
     LoadResult Load(Kernel::KProcess& process, Core::System& system) override;
 
     ResultStatus ReadRomFS(FileSys::VirtualFile& out_file) override;
-    u64 ReadRomFSIVFCOffset() const override;
     ResultStatus ReadUpdateRaw(FileSys::VirtualFile& out_file) override;
     ResultStatus ReadProgramId(u64& out_program_id) override;
     ResultStatus ReadProgramIds(std::vector<u64>& out_program_ids) override;
diff --git a/src/core/loader/xci.cpp b/src/core/loader/xci.cpp
index c7b1b3815..3a76bc788 100644
--- a/src/core/loader/xci.cpp
+++ b/src/core/loader/xci.cpp
@@ -89,10 +89,6 @@ ResultStatus AppLoader_XCI::ReadRomFS(FileSys::VirtualFile& out_file) {
     return nca_loader->ReadRomFS(out_file);
 }
 
-u64 AppLoader_XCI::ReadRomFSIVFCOffset() const {
-    return nca_loader->ReadRomFSIVFCOffset();
-}
-
 ResultStatus AppLoader_XCI::ReadUpdateRaw(FileSys::VirtualFile& out_file) {
     u64 program_id{};
     nca_loader->ReadProgramId(program_id);
diff --git a/src/core/loader/xci.h b/src/core/loader/xci.h
index 2affb6c6e..ff05e6f62 100644
--- a/src/core/loader/xci.h
+++ b/src/core/loader/xci.h
@@ -46,7 +46,6 @@ public:
     LoadResult Load(Kernel::KProcess& process, Core::System& system) override;
 
     ResultStatus ReadRomFS(FileSys::VirtualFile& out_file) override;
-    u64 ReadRomFSIVFCOffset() const override;
     ResultStatus ReadUpdateRaw(FileSys::VirtualFile& out_file) override;
     ResultStatus ReadProgramId(u64& out_program_id) override;
     ResultStatus ReadProgramIds(std::vector<u64>& out_program_ids) override;