Kernel/Loader: Grab the system mode from the NCCH ExHeader.

3dsx and elf files default to system mode 2 (96MB allocated to the application).

This allows Home Menu to boot without modifications.
Closes #1849

7 files changed, 34 insertions, 9 deletions

diff --git a/src/core/hle/kernel/kernel.cpp b/src/core/hle/kernel/kernel.cpp
index 9e1795927..0c8752670 100644
--- a/src/core/hle/kernel/kernel.cpp
+++ b/src/core/hle/kernel/kernel.cpp
@@ -124,13 +124,11 @@ void HandleTable::Clear() {
 }
 
 /// Initialize the kernel
-void Init() {
+void Init(u32 system_mode) {
     ConfigMem::Init();
     SharedPage::Init();
 
-    // TODO(yuriks): The memory type parameter needs to be determined by the ExHeader field instead
-    // For now it defaults to the one with a largest allocation to the app
-    Kernel::MemoryInit(2); // Allocates 96MB to the application
+    Kernel::MemoryInit(system_mode);
 
     Kernel::ResourceLimitsInit();
     Kernel::ThreadingInit();
diff --git a/src/core/hle/kernel/kernel.h b/src/core/hle/kernel/kernel.h
index 6b8dbecff..231cf7b75 100644
--- a/src/core/hle/kernel/kernel.h
+++ b/src/core/hle/kernel/kernel.h
@@ -286,8 +286,8 @@ private:
 
 extern HandleTable g_handle_table;
 
-/// Initialize the kernel
-void Init();
+/// Initialize the kernel with the specified system mode.
+void Init(u32 system_mode);
 
 /// Shutdown the kernel
 void Shutdown();
diff --git a/src/core/loader/loader.h b/src/core/loader/loader.h
index 9652d7ac5..e62f77b9c 100644
--- a/src/core/loader/loader.h
+++ b/src/core/loader/loader.h
@@ -96,6 +96,17 @@ public:
     virtual ResultStatus Load() = 0;
 
     /**
+     * Loads the system mode that this application needs.
+     * This function defaults to 2 (96MB allocated to the application) if it can't read the information.
+     * @param system_mode Out variable where the system mode will be stored.
+     * @returns ResultStatus result of the operation
+     */
+    virtual ResultStatus LoadKernelSystemMode(u32& system_mode) {
+        system_mode = 2; // 96MB allocated to the application.
+        return ResultStatus::Success;
+    }
+
+    /**
      * Get the code (typically .code section) of the application
      * @param buffer Reference to buffer to store data
      * @return ResultStatus result of function
diff --git a/src/core/loader/ncch.cpp b/src/core/loader/ncch.cpp
index fadd7b16b..6fbaf4036 100644
--- a/src/core/loader/ncch.cpp
+++ b/src/core/loader/ncch.cpp
@@ -117,6 +117,14 @@ FileType AppLoader_NCCH::IdentifyType(FileUtil::IOFile& file) {
     return FileType::Error;
 }
 
+ResultStatus AppLoader_NCCH::LoadKernelSystemMode(u32& memory_type) {
+    ResultStatus result = LoadExeFS();
+    if (result != ResultStatus::Success)
+        return result;
+    memory_type = exheader_header.arm11_system_local_caps.system_mode;
+    return ResultStatus::Success;
+}
+
 ResultStatus AppLoader_NCCH::LoadExec() {
     using Kernel::SharedPtr;
     using Kernel::CodeSet;
@@ -277,6 +285,7 @@ ResultStatus AppLoader_NCCH::LoadExeFS() {
     LOG_DEBUG(Loader, "Core version:                %d", core_version);
     LOG_DEBUG(Loader, "Thread priority:             0x%X", priority);
     LOG_DEBUG(Loader, "Resource limit category:     %d", resource_limit_category);
+    LOG_DEBUG(Loader, "System Mode:                 %d", exheader_header.arm11_system_local_caps.system_mode);
 
     if (exheader_header.arm11_system_local_caps.program_id != ncch_header.program_id) {
         LOG_ERROR(Loader, "ExHeader Program ID mismatch: the ROM is probably encrypted.");
diff --git a/src/core/loader/ncch.h b/src/core/loader/ncch.h
index f8718d063..63947c28e 100644
--- a/src/core/loader/ncch.h
+++ b/src/core/loader/ncch.h
@@ -186,6 +186,13 @@ public:
     ResultStatus Load() override;
 
     /**
+     * Loads the Exheader and returns the system mode for this application.
+     * @param system_mode Out variable where the system mode will be stored.
+     * @return ResultStatus result of the operation
+     */
+    ResultStatus LoadKernelSystemMode(u32& system_mode);
+
+    /**
      * Get the code (typically .code section) of the application
      * @param buffer Reference to buffer to store data
      * @return ResultStatus result of function
diff --git a/src/core/system.cpp b/src/core/system.cpp
index 7d54811a0..a5f763805 100644
--- a/src/core/system.cpp
+++ b/src/core/system.cpp
@@ -17,12 +17,12 @@ namespace System {
 
 static bool is_powered_on{false};
 
-Result Init(EmuWindow* emu_window) {
+Result Init(EmuWindow* emu_window, u32 system_mode) {
     Core::Init();
     CoreTiming::Init();
     Memory::Init();
     HW::Init();
-    Kernel::Init();
+    Kernel::Init(system_mode);
     HLE::Init();
     if (!VideoCore::Init(emu_window)) {
         return Result::ErrorInitVideoCore;
diff --git a/src/core/system.h b/src/core/system.h
index 6d672b1b5..b41fc088a 100644
--- a/src/core/system.h
+++ b/src/core/system.h
@@ -15,7 +15,7 @@ enum class Result {
     ErrorInitVideoCore, ///< Something went wrong during video core init
 };
 
-Result Init(EmuWindow* emu_window);
+Result Init(EmuWindow* emu_window, u32 system_mode);
 bool IsPoweredOn();
 void Shutdown();
 }