5 files changed, 116 insertions, 0 deletions

diff --git a/src/core/CMakeLists.txt b/src/core/CMakeLists.txt
index b67226d8d..d248b454c 100644
--- a/src/core/CMakeLists.txt
+++ b/src/core/CMakeLists.txt
@@ -69,6 +69,7 @@ set(SRCS
             hle/service/y2r_u.cpp
             hle/config_mem.cpp
             hle/hle.cpp
+            hle/shared_page.cpp
             hle/svc.cpp
             hw/gpu.cpp
             hw/hw.cpp
@@ -163,6 +164,7 @@ set(HEADERS
             hle/result.h
             hle/function_wrappers.h
             hle/hle.h
+            hle/shared_page.h
             hle/svc.h
             hw/gpu.h
             hw/hw.h
diff --git a/src/core/hle/hle.cpp b/src/core/hle/hle.cpp
index 33ac12507..f76048d14 100644
--- a/src/core/hle/hle.cpp
+++ b/src/core/hle/hle.cpp
@@ -6,6 +6,7 @@
 
 #include "core/mem_map.h"
 #include "core/hle/hle.h"
+#include "core/hle/shared_page.h"
 #include "core/hle/kernel/thread.h"
 #include "core/hle/service/service.h"
 #include "core/hle/service/fs/archive.h"
@@ -71,6 +72,8 @@ void Init() {
 
     RegisterAllModules();
 
+    SharedPage::Init();
+
     LOG_DEBUG(Kernel, "initialized OK");
 }
 
diff --git a/src/core/hle/shared_page.cpp b/src/core/hle/shared_page.cpp
new file mode 100644
index 000000000..6033a53b4
--- /dev/null
+++ b/src/core/hle/shared_page.cpp
@@ -0,0 +1,80 @@
+// Copyright 2015 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include "common/common_types.h"
+#include "common/log.h"
+
+#include "core/core.h"
+#include "core/mem_map.h"
+#include "core/hle/config_mem.h"
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
+namespace SharedPage {
+
+// helper macro to properly align structure members.
+// Calling INSERT_PADDING_BYTES will add a new member variable with a name like "pad121",
+// depending on the current source line to make sure variable names are unique.
+#define INSERT_PADDING_BYTES_HELPER1(x, y) x ## y
+#define INSERT_PADDING_BYTES_HELPER2(x, y) INSERT_PADDING_BYTES_HELPER1(x, y)
+#define INSERT_PADDING_BYTES(num_words) u8 INSERT_PADDING_BYTES_HELPER2(pad, __LINE__)[(num_words)]
+
+// see http://3dbrew.org/wiki/Configuration_Memory#Shared_Memory_Page_For_ARM11_Processes
+
+#pragma pack(1)
+struct DateTime {
+    u64     date_time;      // 0x0
+    u64     update_tick;    // 0x8
+    INSERT_PADDING_BYTES(0x20 - 0x10); // 0x10
+};
+
+struct SharedPageDef {
+    // most of these names are taken from the 3dbrew page linked above.
+    u32    date_time_selector;  // 0x0
+    u8     running_hw;          // 0x4
+    u8     mcu_hw_info;         // 0x5: don't know what the acronyms mean
+    INSERT_PADDING_BYTES(0x20 - 0x6); // 0x6
+    DateTime date_time_0;       // 0x20
+    DateTime date_time_1;       // 0x40
+    u8      wifi_macaddr[6];    // 0x60
+    u8      wifi_unknown1;      // 0x66: 3dbrew says these are "Likely wifi hardware related"
+    u8      wifi_unknown2;      // 0x67
+    INSERT_PADDING_BYTES(0x80 - 0x68); // 0x68
+    float   sliderstate_3d;     // 0x80
+    u8      ledstate_3d;        // 0x84
+    INSERT_PADDING_BYTES(0xA0 - 0x85); // 0x85
+    u64     menu_title_id;      // 0xA0
+    u64     active_menu_title_id; // 0xA8
+    INSERT_PADDING_BYTES(0x1000 - 0xB0); // 0xB0
+};
+#pragma pack()
+
+static_assert(sizeof(DateTime) == 0x20, "Datetime size is wrong");
+static_assert(sizeof(SharedPageDef) == Memory::SHARED_PAGE_SIZE, "Shared page structure size is wrong");
+
+static SharedPageDef shared_page;
+
+template <typename T>
+inline void Read(T &var, const u32 addr) {
+    u32 offset = addr - Memory::SHARED_PAGE_VADDR;
+    var = *(reinterpret_cast<T*>(((uintptr_t)&shared_page) + offset));
+}
+
+// Explicitly instantiate template functions because we aren't defining this in the header:
+template void Read<u64>(u64 &var, const u32 addr);
+template void Read<u32>(u32 &var, const u32 addr);
+template void Read<u16>(u16 &var, const u32 addr);
+template void Read<u8>(u8 &var, const u32 addr);
+
+void Set3DSlider(float amount) {
+    shared_page.sliderstate_3d = amount;
+    shared_page.ledstate_3d = (amount == 0.0f); // off when non-zero
+}
+
+void Init() {
+    shared_page.running_hw = 0x1; // product
+    Set3DSlider(0.0f);
+}
+
+} // namespace
diff --git a/src/core/hle/shared_page.h b/src/core/hle/shared_page.h
new file mode 100644
index 000000000..8f93545ec
--- /dev/null
+++ b/src/core/hle/shared_page.h
@@ -0,0 +1,26 @@
+// Copyright 2015 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+/**
+ * The shared page stores various runtime configuration settings. This memory page is
+ * read-only for user processes (there is a bit in the header that grants the process
+ * write access, according to 3dbrew; this is not emulated)
+ */
+
+#include "common/common_types.h"
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+
+namespace SharedPage {
+
+template <typename T>
+void Read(T &var, const u32 addr);
+
+void Set3DSlider(float amount);
+
+void Init();
+
+} // namespace
diff --git a/src/core/mem_map_funcs.cpp b/src/core/mem_map_funcs.cpp
index 97ef1c5a3..0e3b81b28 100644
--- a/src/core/mem_map_funcs.cpp
+++ b/src/core/mem_map_funcs.cpp
@@ -9,6 +9,7 @@
 #include "core/mem_map.h"
 #include "core/hw/hw.h"
 #include "hle/config_mem.h"
+#include "hle/shared_page.h"
 
 namespace Memory {
 
@@ -82,6 +83,10 @@ inline void Read(T &var, const VAddr vaddr) {
     } else if ((vaddr >= CONFIG_MEMORY_VADDR)  && (vaddr < CONFIG_MEMORY_VADDR_END)) {
         ConfigMem::Read<T>(var, vaddr);
 
+    // Shared page
+    } else if ((vaddr >= SHARED_PAGE_VADDR)  && (vaddr < SHARED_PAGE_VADDR_END)) {
+        SharedPage::Read<T>(var, vaddr);
+
     // DSP memory
     } else if ((vaddr >= DSP_MEMORY_VADDR)  && (vaddr < DSP_MEMORY_VADDR_END)) {
         var = *((const T*)&g_dsp_mem[vaddr - DSP_MEMORY_VADDR]);