9 files changed, 150 insertions, 47 deletions

diff --git a/src/common/common_paths.h b/src/common/common_paths.h
index a86889756..966402a3d 100644
--- a/src/common/common_paths.h
+++ b/src/common/common_paths.h
@@ -42,6 +42,7 @@
 #define SDMC_DIR          "sdmc"
 #define SAVEDATA_DIR      "savedata"
 #define SYSDATA_DIR       "sysdata"
+#define SYSSAVEDATA_DIR   "syssavedata"
 #define SHADERCACHE_DIR   "shader_cache"
 #define STATESAVES_DIR    "state_saves"
 #define SCREENSHOTS_DIR   "screenShots"
diff --git a/src/common/file_util.cpp b/src/common/file_util.cpp
index 42cdf3262..20c680571 100644
--- a/src/common/file_util.cpp
+++ b/src/common/file_util.cpp
@@ -678,6 +678,7 @@ const std::string& GetUserPath(const unsigned int DirIDX, const std::string &new
         paths[D_SDMC_IDX]           = paths[D_USER_IDX] + SDMC_DIR DIR_SEP;
         paths[D_SAVEDATA_IDX]       = paths[D_USER_IDX] + SAVEDATA_DIR DIR_SEP;
         paths[D_SYSDATA_IDX]        = paths[D_USER_IDX] + SYSDATA_DIR DIR_SEP;
+        paths[D_SYSSAVEDATA_IDX]    = paths[D_USER_IDX] + SYSSAVEDATA_DIR DIR_SEP;
         paths[D_SHADERCACHE_IDX]    = paths[D_USER_IDX] + SHADERCACHE_DIR DIR_SEP;
         paths[D_SHADERS_IDX]        = paths[D_USER_IDX] + SHADERS_DIR DIR_SEP;
         paths[D_STATESAVES_IDX]     = paths[D_USER_IDX] + STATESAVES_DIR DIR_SEP;
@@ -720,6 +721,7 @@ const std::string& GetUserPath(const unsigned int DirIDX, const std::string &new
             paths[D_CACHE_IDX]          = paths[D_USER_IDX] + CACHE_DIR DIR_SEP;
             paths[D_SDMC_IDX]           = paths[D_USER_IDX] + SDMC_DIR DIR_SEP;
             paths[D_SAVEDATA_IDX]       = paths[D_USER_IDX] + SAVEDATA_DIR DIR_SEP;
+            paths[D_SYSSAVEDATA_IDX]    = paths[D_USER_IDX] + SYSSAVEDATA_DIR DIR_SEP;
             paths[D_SHADERCACHE_IDX]    = paths[D_USER_IDX] + SHADERCACHE_DIR DIR_SEP;
             paths[D_SHADERS_IDX]        = paths[D_USER_IDX] + SHADERS_DIR DIR_SEP;
             paths[D_STATESAVES_IDX]     = paths[D_USER_IDX] + STATESAVES_DIR DIR_SEP;
diff --git a/src/common/file_util.h b/src/common/file_util.h
index e691b6139..b1a60fb81 100644
--- a/src/common/file_util.h
+++ b/src/common/file_util.h
@@ -29,6 +29,7 @@ enum {
     D_SDMC_IDX,
     D_SAVEDATA_IDX,
     D_SYSDATA_IDX,
+    D_SYSSAVEDATA_IDX,
     D_HIRESTEXTURES_IDX,
     D_DUMP_IDX,
     D_DUMPFRAMES_IDX,
diff --git a/src/core/CMakeLists.txt b/src/core/CMakeLists.txt
index f71232c1a..3381524e3 100644
--- a/src/core/CMakeLists.txt
+++ b/src/core/CMakeLists.txt
@@ -20,6 +20,7 @@ set(SRCS
             file_sys/archive_romfs.cpp
             file_sys/archive_savedata.cpp
             file_sys/archive_sdmc.cpp
+            file_sys/archive_systemsavedata.cpp
             file_sys/disk_archive.cpp
             file_sys/file_romfs.cpp
             file_sys/directory_romfs.cpp
@@ -101,6 +102,7 @@ set(HEADERS
             file_sys/archive_romfs.h
             file_sys/archive_savedata.h
             file_sys/archive_sdmc.h
+            file_sys/archive_systemsavedata.h
             file_sys/disk_archive.h
             file_sys/file_backend.h
             file_sys/file_romfs.h
diff --git a/src/core/arm/interpreter/armemu.cpp b/src/core/arm/interpreter/armemu.cpp
index 3b1a36bdd..07d205755 100644
--- a/src/core/arm/interpreter/armemu.cpp
+++ b/src/core/arm/interpreter/armemu.cpp
@@ -5827,8 +5827,10 @@ L_stm_s_takeabort:
         case 0x3f:
             printf ("Unhandled v6 insn: rbit\n");
             break;
-        case 0x61:
-            if ((instr & 0xFF0) == 0xf70) { //ssub16
+        case 0x61: // SSUB16, SADD16, SSAX, and SASX
+            if ((instr & 0xFF0) == 0xf70 || (instr & 0xFF0) == 0xf10 ||
+                (instr & 0xFF0) == 0xf50 || (instr & 0xFF0) == 0xf30)
+            {
                 const u8 rd_idx = BITS(12, 15);
                 const u8 rm_idx = BITS(0, 3);
                 const u8 rn_idx = BITS(16, 19);
@@ -5836,40 +5838,52 @@ L_stm_s_takeabort:
                 const s16 rn_hi = ((state->Reg[rn_idx] >> 16) & 0xFFFF);
                 const s16 rm_lo = (state->Reg[rm_idx] & 0xFFFF);
                 const s16 rm_hi = ((state->Reg[rm_idx] >> 16) & 0xFFFF);
-                state->Reg[rd_idx] = ((rn_lo - rm_lo) & 0xFFFF) | (((rn_hi - rm_hi) & 0xFFFF) << 16);
-                return 1;
-            } else if ((instr & 0xFF0) == 0xf10) { //sadd16
-                const u8 rd_idx = BITS(12, 15);
-                const u8 rm_idx = BITS(0, 3);
-                const u8 rn_idx = BITS(16, 19);
-                const s16 rm_lo = (state->Reg[rm_idx] & 0xFFFF);
-                const s16 rm_hi = ((state->Reg[rm_idx] >> 16) & 0xFFFF);
-                const s16 rn_lo = (state->Reg[rn_idx] & 0xFFFF);
-                const s16 rn_hi = ((state->Reg[rn_idx] >> 16) & 0xFFFF);
 
-                state->Reg[rd_idx] = ((rn_lo + rm_lo) & 0xFFFF) | (((rn_hi + rm_hi) & 0xFFFF) << 16);
-                return 1;
-            } else if ((instr & 0xFF0) == 0xf50) { //ssax
-                u8 tar = BITS(12, 15);
-                u8 src1 = BITS(16, 19);
-                u8 src2 = BITS(0, 3);
-                s16 a1 = (state->Reg[src1] & 0xFFFF);
-                s16 a2 = ((state->Reg[src1] >> 0x10) & 0xFFFF);
-                s16 b1 = (state->Reg[src2] & 0xFFFF);
-                s16 b2 = ((state->Reg[src2] >> 0x10) & 0xFFFF);
-                                state->Reg[tar] = ((a1 + b2) & 0xFFFF) | (((a2 - b1) & 0xFFFF) << 0x10);
-                return 1;
-            } else if ((instr & 0xFF0) == 0xf30) { //sasx
-                u8 tar = BITS(12, 15);
-                u8 src1 = BITS(16, 19);
-                u8 src2 = BITS(0, 3);
-                s16 a1 = (state->Reg[src1] & 0xFFFF);
-                s16 a2 = ((state->Reg[src1] >> 0x10) & 0xFFFF);
-                s16 b1 = (state->Reg[src2] & 0xFFFF);
-                s16 b2 = ((state->Reg[src2] >> 0x10) & 0xFFFF);
-                                state->Reg[tar] = ((a1 - b2) & 0xFFFF) | (((a2 + b1) & 0xFFFF) << 0x10);
+                s32 lo_result;
+                s32 hi_result;
+
+                // SSUB16
+                if ((instr & 0xFF0) == 0xf70) {
+                    lo_result = (rn_lo - rm_lo);
+                    hi_result = (rn_hi - rm_hi);
+                }
+                // SADD16
+                else if ((instr & 0xFF0) == 0xf10) {
+                    lo_result = (rn_lo + rm_lo);
+                    hi_result = (rn_hi + rm_hi);
+                }
+                // SSAX
+                else if ((instr & 0xFF0) == 0xf50) {
+                    lo_result = (rn_lo + rm_hi);
+                    hi_result = (rn_hi - rm_lo);
+                }
+                // SASX
+                else {
+                    lo_result = (rn_lo - rm_hi);
+                    hi_result = (rn_hi + rm_lo);
+                }
+
+                state->Reg[rd_idx] = (lo_result & 0xFFFF) | ((hi_result & 0xFFFF) << 16);
+
+                if (lo_result >= 0) {
+                    state->Cpsr |= (1 << 16);
+                    state->Cpsr |= (1 << 17);
+                } else {
+                    state->Cpsr &= ~(1 << 16);
+                    state->Cpsr &= ~(1 << 17);
+                }
+
+                if (hi_result >= 0) {
+                    state->Cpsr |= (1 << 18);
+                    state->Cpsr |= (1 << 19);
+                } else {
+                    state->Cpsr &= ~(1 << 18);
+                    state->Cpsr &= ~(1 << 19);
+                }
                 return 1;
-            } else printf ("Unhandled v6 insn: sadd/ssub/ssax/sasx\n");
+            } else {
+                printf("Unhandled v6 insn: %08x", BITS(20, 27));
+            }
             break;
         case 0x62: // QSUB16 and QADD16
             if ((instr & 0xFF0) == 0xf70 || (instr & 0xFF0) == 0xf10) {
@@ -6203,18 +6217,27 @@ L_stm_s_takeabort:
                                         //ichfly
                                         //USAT16
                                 {
-                                        u8 tar = BITS(12, 15);
-                                        u8 src = BITS(0, 3);
-                                        u8 val = BITS(16, 19);
-                                        s16 a1 = (state->Reg[src]);
-                                        s16 a2 = (state->Reg[src] >> 0x10);
-                                        s16 max = 0xFFFF >> (16 - val);
-                                        if (max < a1) a1 = max;
-                                        if (max < a2) a2 = max;
-                                        u32 temp2 = ((u32)(a2)) << 0x10;
-                                        state->Reg[tar] = (a1 & 0xFFFF) | (temp2);
+                                        const u8 rd_idx = BITS(12, 15);
+                                        const u8 rn_idx = BITS(0, 3);
+                                        const u8 num_bits = BITS(16, 19);
+                                        const s16 max = 0xFFFF >> (16 - num_bits);
+                                        s16 rn_lo = (state->Reg[rn_idx]);
+                                        s16 rn_hi = (state->Reg[rn_idx] >> 16);
+                                        
+                                        if (max < rn_lo)
+                                                rn_lo = max;
+                                        else if (rn_lo < 0)
+                                                rn_lo = 0;
+
+                                        if (max < rn_hi)
+                                                rn_hi = max;
+                                        else if (rn_hi < 0)
+                                                rn_hi = 0;
+                                        
+                                        state->Reg[rd_idx] = (rn_lo & 0xFFFF) | ((rn_hi << 16) & 0xFFFF);
+                                        return 1;
                                 }
-                                return 1;
+
                                 default:
                                         break;
                         }
diff --git a/src/core/file_sys/archive_savedata.h b/src/core/file_sys/archive_savedata.h
index b3e561130..d394ad37e 100644
--- a/src/core/file_sys/archive_savedata.h
+++ b/src/core/file_sys/archive_savedata.h
@@ -21,8 +21,7 @@ public:
 
     /**
      * Initialize the archive.
-     * @return CreateSaveDataResult AlreadyExists if the SaveData folder already exists,
-     * Success if it was created properly and Failure if there was any error
+     * @return true if it initialized successfully
      */
     bool Initialize();
 
diff --git a/src/core/file_sys/archive_systemsavedata.cpp b/src/core/file_sys/archive_systemsavedata.cpp
new file mode 100644
index 000000000..dc2c23b41
--- /dev/null
+++ b/src/core/file_sys/archive_systemsavedata.cpp
@@ -0,0 +1,33 @@
+// Copyright 2014 Citra Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#include <sys/stat.h>
+
+#include "common/common_types.h"
+#include "common/file_util.h"
+
+#include "core/file_sys/archive_systemsavedata.h"
+#include "core/file_sys/disk_archive.h"
+#include "core/settings.h"
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+// FileSys namespace
+
+namespace FileSys {
+
+Archive_SystemSaveData::Archive_SystemSaveData(const std::string& mount_point)
+        : DiskArchive(mount_point) {
+    LOG_INFO(Service_FS, "Directory %s set as SystemSaveData.", this->mount_point.c_str());
+}
+
+bool Archive_SystemSaveData::Initialize() {
+    if (!FileUtil::CreateFullPath(mount_point)) {
+        LOG_ERROR(Service_FS, "Unable to create SystemSaveData path.");
+        return false;
+    }
+
+    return true;
+}
+
+} // namespace FileSys
diff --git a/src/core/file_sys/archive_systemsavedata.h b/src/core/file_sys/archive_systemsavedata.h
new file mode 100644
index 000000000..360ed1e13
--- /dev/null
+++ b/src/core/file_sys/archive_systemsavedata.h
@@ -0,0 +1,33 @@
+// Copyright 2014 Citra Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include "common/common_types.h"
+
+#include "core/file_sys/disk_archive.h"
+#include "core/loader/loader.h"
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+// FileSys namespace
+
+namespace FileSys {
+
+/// File system interface to the SystemSaveData archive
+/// TODO(Subv): This archive should point to a location in the NAND, 
+/// specifically nand:/data/<ID0>/sysdata/<SaveID-Low>/<SaveID-High>
+class Archive_SystemSaveData final : public DiskArchive {
+public:
+    Archive_SystemSaveData(const std::string& mount_point);
+
+    /**
+     * Initialize the archive.
+     * @return true if it initialized successfully
+     */
+    bool Initialize();
+
+    std::string GetName() const override { return "SystemSaveData"; }
+};
+
+} // namespace FileSys
diff --git a/src/core/hle/service/fs/archive.cpp b/src/core/hle/service/fs/archive.cpp
index 9c3834733..5ab82729c 100644
--- a/src/core/hle/service/fs/archive.cpp
+++ b/src/core/hle/service/fs/archive.cpp
@@ -419,6 +419,15 @@ void ArchiveInit() {
         CreateArchive(std::move(sdmc_archive), ArchiveIdCode::SDMC);
     else
         LOG_ERROR(Service_FS, "Can't instantiate SDMC archive with path %s", sdmc_directory.c_str());
+
+    std::string systemsavedata_directory = FileUtil::GetUserPath(D_SYSSAVEDATA_IDX);
+    auto systemsavedata_archive = std::make_unique<FileSys::Archive_SDMC>(systemsavedata_directory);
+    if (systemsavedata_archive->Initialize()) {
+        CreateArchive(std::move(systemsavedata_archive), ArchiveIdCode::SystemSaveData);
+    } else {
+        LOG_ERROR(Service_FS, "Can't instantiate SystemSaveData archive with path %s",
+            systemsavedata_directory.c_str());
+    }
 }
 
 /// Shutdown archives