8 files changed, 321 insertions, 23 deletions

diff --git a/src/core/CMakeLists.txt b/src/core/CMakeLists.txt
index b80efe192..360f407f3 100644
--- a/src/core/CMakeLists.txt
+++ b/src/core/CMakeLists.txt
@@ -60,6 +60,7 @@ set(SRCS
             hle/kernel/timer.cpp
             hle/kernel/vm_manager.cpp
             hle/kernel/wait_object.cpp
+            hle/romfs.cpp
             hle/service/ac/ac.cpp
             hle/service/ac/ac_i.cpp
             hle/service/ac/ac_u.cpp
@@ -258,6 +259,7 @@ set(HEADERS
             hle/kernel/vm_manager.h
             hle/kernel/wait_object.h
             hle/result.h
+            hle/romfs.h
             hle/service/ac/ac.h
             hle/service/ac/ac_i.h
             hle/service/ac/ac_u.h
diff --git a/src/core/hle/romfs.cpp b/src/core/hle/romfs.cpp
new file mode 100644
index 000000000..3157df71d
--- /dev/null
+++ b/src/core/hle/romfs.cpp
@@ -0,0 +1,102 @@
+// Copyright 2017 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <cstring>
+#include "common/swap.h"
+#include "core/hle/romfs.h"
+
+namespace RomFS {
+
+struct Header {
+    u32_le header_length;
+    u32_le dir_hash_table_offset;
+    u32_le dir_hash_table_length;
+    u32_le dir_table_offset;
+    u32_le dir_table_length;
+    u32_le file_hash_table_offset;
+    u32_le file_hash_table_length;
+    u32_le file_table_offset;
+    u32_le file_table_length;
+    u32_le data_offset;
+};
+
+static_assert(sizeof(Header) == 0x28, "Header has incorrect size");
+
+struct DirectoryMetadata {
+    u32_le parent_dir_offset;
+    u32_le next_dir_offset;
+    u32_le first_child_dir_offset;
+    u32_le first_file_offset;
+    u32_le same_hash_next_dir_offset;
+    u32_le name_length; // in bytes
+    // followed by directory name
+};
+
+static_assert(sizeof(DirectoryMetadata) == 0x18, "DirectoryMetadata has incorrect size");
+
+struct FileMetadata {
+    u32_le parent_dir_offset;
+    u32_le next_file_offset;
+    u64_le data_offset;
+    u64_le data_length;
+    u32_le same_hash_next_file_offset;
+    u32_le name_length; // in bytes
+    // followed by file name
+};
+
+static_assert(sizeof(FileMetadata) == 0x20, "FileMetadata has incorrect size");
+
+static bool MatchName(const u8* buffer, u32 name_length, const std::u16string& name) {
+    std::vector<char16_t> name_buffer(name_length / sizeof(char16_t));
+    std::memcpy(name_buffer.data(), buffer, name_length);
+    return name == std::u16string(name_buffer.begin(), name_buffer.end());
+}
+
+const u8* GetFilePointer(const u8* romfs, const std::vector<std::u16string>& path) {
+    constexpr u32 INVALID_FIELD = 0xFFFFFFFF;
+
+    // Split path into directory names and file name
+    std::vector<std::u16string> dir_names = path;
+    dir_names.pop_back();
+    const std::u16string& file_name = path.back();
+
+    Header header;
+    std::memcpy(&header, romfs, sizeof(header));
+
+    // Find directories of each level
+    DirectoryMetadata dir;
+    const u8* current_dir = romfs + header.dir_table_offset;
+    std::memcpy(&dir, current_dir, sizeof(dir));
+    for (const std::u16string& dir_name : dir_names) {
+        u32 child_dir_offset;
+        child_dir_offset = dir.first_child_dir_offset;
+        while (true) {
+            if (child_dir_offset == INVALID_FIELD) {
+                return nullptr;
+            }
+            const u8* current_child_dir = romfs + header.dir_table_offset + child_dir_offset;
+            std::memcpy(&dir, current_child_dir, sizeof(dir));
+            if (MatchName(current_child_dir + sizeof(dir), dir.name_length, dir_name)) {
+                current_dir = current_child_dir;
+                break;
+            }
+            child_dir_offset = dir.next_dir_offset;
+        }
+    }
+
+    // Find the file
+    FileMetadata file;
+    u32 file_offset = dir.first_file_offset;
+    while (file_offset != INVALID_FIELD) {
+        const u8* current_file = romfs + header.file_table_offset + file_offset;
+        std::memcpy(&file, current_file, sizeof(file));
+        if (MatchName(current_file + sizeof(file), file.name_length, file_name)) {
+            return romfs + header.data_offset + file.data_offset;
+        }
+        file_offset = file.next_file_offset;
+    }
+    return nullptr;
+}
+
+} // namespace RomFS
diff --git a/src/core/hle/romfs.h b/src/core/hle/romfs.h
new file mode 100644
index 000000000..ee9f29760
--- /dev/null
+++ b/src/core/hle/romfs.h
@@ -0,0 +1,22 @@
+// Copyright 2017 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <string>
+#include <vector>
+#include "common/common_types.h"
+
+namespace RomFS {
+
+/**
+ * Gets the pointer to a file in a RomFS image.
+ * @param romfs The pointer to the RomFS image
+ * @param path A vector containing the directory names and file name of the path to the file
+ * @return the pointer to the file
+ * @todo reimplement this with a full RomFS manager
+ */
+const u8* GetFilePointer(const u8* romfs, const std::vector<std::u16string>& path);
+
+} // namespace RomFS
diff --git a/src/core/hle/service/apt/apt.cpp b/src/core/hle/service/apt/apt.cpp
index 25e7b777d..df4b5cc3f 100644
--- a/src/core/hle/service/apt/apt.cpp
+++ b/src/core/hle/service/apt/apt.cpp
@@ -6,11 +6,13 @@
 #include "common/file_util.h"
 #include "common/logging/log.h"
 #include "core/core.h"
+#include "core/file_sys/file_backend.h"
 #include "core/hle/applets/applet.h"
 #include "core/hle/kernel/event.h"
 #include "core/hle/kernel/mutex.h"
 #include "core/hle/kernel/process.h"
 #include "core/hle/kernel/shared_memory.h"
+#include "core/hle/romfs.h"
 #include "core/hle/service/apt/apt.h"
 #include "core/hle/service/apt/apt_a.h"
 #include "core/hle/service/apt/apt_s.h"
@@ -27,6 +29,7 @@ namespace APT {
 
 /// Handle to shared memory region designated to for shared system font
 static Kernel::SharedPtr<Kernel::SharedMemory> shared_font_mem;
+static bool shared_font_loaded = false;
 static bool shared_font_relocated = false;
 
 static Kernel::SharedPtr<Kernel::Mutex> lock;
@@ -71,7 +74,7 @@ void Initialize(Service::Interface* self) {
 void GetSharedFont(Service::Interface* self) {
     IPC::RequestParser rp(Kernel::GetCommandBuffer(), 0x44, 0, 0); // 0x00440000
     IPC::RequestBuilder rb = rp.MakeBuilder(2, 2);
-    if (!shared_font_mem) {
+    if (!shared_font_loaded) {
         LOG_ERROR(Service_APT, "shared font file missing - go dump it from your 3ds");
         rb.Push<u32>(-1); // TODO: Find the right error code
         rb.Skip(1 + 2, true);
@@ -644,36 +647,146 @@ void CheckNew3DS(Service::Interface* self) {
     LOG_WARNING(Service_APT, "(STUBBED) called");
 }
 
-void Init() {
-    AddService(new APT_A_Interface);
-    AddService(new APT_S_Interface);
-    AddService(new APT_U_Interface);
-
-    HLE::Applets::Init();
-
-    // Load the shared system font (if available).
+static u32 DecompressLZ11(const u8* in, u8* out) {
+    u32_le decompressed_size;
+    memcpy(&decompressed_size, in, sizeof(u32));
+    in += 4;
+
+    u8 type = decompressed_size & 0xFF;
+    ASSERT(type == 0x11);
+    decompressed_size >>= 8;
+
+    u32 current_out_size = 0;
+    u8 flags = 0, mask = 1;
+    while (current_out_size < decompressed_size) {
+        if (mask == 1) {
+            flags = *(in++);
+            mask = 0x80;
+        } else {
+            mask >>= 1;
+        }
+
+        if (flags & mask) {
+            u8 byte1 = *(in++);
+            u32 length = byte1 >> 4;
+            u32 offset;
+            if (length == 0) {
+                u8 byte2 = *(in++);
+                u8 byte3 = *(in++);
+                length = (((byte1 & 0x0F) << 4) | (byte2 >> 4)) + 0x11;
+                offset = (((byte2 & 0x0F) << 8) | byte3) + 0x1;
+            } else if (length == 1) {
+                u8 byte2 = *(in++);
+                u8 byte3 = *(in++);
+                u8 byte4 = *(in++);
+                length = (((byte1 & 0x0F) << 12) | (byte2 << 4) | (byte3 >> 4)) + 0x111;
+                offset = (((byte3 & 0x0F) << 8) | byte4) + 0x1;
+            } else {
+                u8 byte2 = *(in++);
+                length = (byte1 >> 4) + 0x1;
+                offset = (((byte1 & 0x0F) << 8) | byte2) + 0x1;
+            }
+
+            for (u32 i = 0; i < length; i++) {
+                *out = *(out - offset);
+                ++out;
+            }
+
+            current_out_size += length;
+        } else {
+            *(out++) = *(in++);
+            current_out_size++;
+        }
+    }
+    return decompressed_size;
+}
+
+static bool LoadSharedFont() {
+    // TODO (wwylele): load different font archive for region CHN/KOR/TWN
+    const u64_le shared_font_archive_id_low = 0x0004009b00014002;
+    const u64_le shared_font_archive_id_high = 0x00000001ffffff00;
+    std::vector<u8> shared_font_archive_id(16);
+    std::memcpy(&shared_font_archive_id[0], &shared_font_archive_id_low, sizeof(u64));
+    std::memcpy(&shared_font_archive_id[8], &shared_font_archive_id_high, sizeof(u64));
+    FileSys::Path archive_path(shared_font_archive_id);
+    auto archive_result = Service::FS::OpenArchive(Service::FS::ArchiveIdCode::NCCH, archive_path);
+    if (archive_result.Failed())
+        return false;
+
+    std::vector<u8> romfs_path(20, 0); // 20-byte all zero path for opening RomFS
+    FileSys::Path file_path(romfs_path);
+    FileSys::Mode open_mode = {};
+    open_mode.read_flag.Assign(1);
+    auto file_result = Service::FS::OpenFileFromArchive(*archive_result, file_path, open_mode);
+    if (file_result.Failed())
+        return false;
+
+    auto romfs = std::move(file_result).Unwrap();
+    std::vector<u8> romfs_buffer(romfs->backend->GetSize());
+    romfs->backend->Read(0, romfs_buffer.size(), romfs_buffer.data());
+    romfs->backend->Close();
+
+    const u8* font_file = RomFS::GetFilePointer(romfs_buffer.data(), {u"cbf_std.bcfnt.lz"});
+    if (font_file == nullptr)
+        return false;
+
+    struct {
+        u32_le status;
+        u32_le region;
+        u32_le decompressed_size;
+        INSERT_PADDING_WORDS(0x1D);
+    } shared_font_header{};
+    static_assert(sizeof(shared_font_header) == 0x80, "shared_font_header has incorrect size");
+
+    shared_font_header.status = 2; // successfully loaded
+    shared_font_header.region = 1; // region JPN/EUR/USA
+    shared_font_header.decompressed_size =
+        DecompressLZ11(font_file, shared_font_mem->GetPointer(0x80));
+    std::memcpy(shared_font_mem->GetPointer(), &shared_font_header, sizeof(shared_font_header));
+    *shared_font_mem->GetPointer(0x83) = 'U'; // Change the magic from "CFNT" to "CFNU"
+
+    return true;
+}
+
+static bool LoadLegacySharedFont() {
+    // This is the legacy method to load shared font.
     // The expected format is a decrypted, uncompressed BCFNT file with the 0x80 byte header
     // generated by the APT:U service. The best way to get is by dumping it from RAM. We've provided
     // a homebrew app to do this: https://github.com/citra-emu/3dsutils. Put the resulting file
     // "shared_font.bin" in the Citra "sysdata" directory.
-
     std::string filepath = FileUtil::GetUserPath(D_SYSDATA_IDX) + SHARED_FONT;
 
     FileUtil::CreateFullPath(filepath); // Create path if not already created
     FileUtil::IOFile file(filepath, "rb");
-
     if (file.IsOpen()) {
-        // Create shared font memory object
-        using Kernel::MemoryPermission;
-        shared_font_mem =
-            Kernel::SharedMemory::Create(nullptr, 0x332000, // 3272 KB
-                                         MemoryPermission::ReadWrite, MemoryPermission::Read, 0,
-                                         Kernel::MemoryRegion::SYSTEM, "APT:SharedFont");
-        // Read shared font data
         file.ReadBytes(shared_font_mem->GetPointer(), file.GetSize());
+        return true;
+    }
+
+    return false;
+}
+
+void Init() {
+    AddService(new APT_A_Interface);
+    AddService(new APT_S_Interface);
+    AddService(new APT_U_Interface);
+
+    HLE::Applets::Init();
+
+    using Kernel::MemoryPermission;
+    shared_font_mem =
+        Kernel::SharedMemory::Create(nullptr, 0x332000, // 3272 KB
+                                     MemoryPermission::ReadWrite, MemoryPermission::Read, 0,
+                                     Kernel::MemoryRegion::SYSTEM, "APT:SharedFont");
+
+    if (LoadSharedFont()) {
+        shared_font_loaded = true;
+    } else if (LoadLegacySharedFont()) {
+        LOG_WARNING(Service_APT, "Loaded shared font by legacy method");
+        shared_font_loaded = true;
     } else {
-        LOG_WARNING(Service_APT, "Unable to load shared font: %s", filepath.c_str());
-        shared_font_mem = nullptr;
+        LOG_WARNING(Service_APT, "Unable to load shared font");
+        shared_font_loaded = false;
     }
 
     lock = Kernel::Mutex::Create(false, "APT_U:Lock");
@@ -693,6 +806,7 @@ void Init() {
 
 void Shutdown() {
     shared_font_mem = nullptr;
+    shared_font_loaded = false;
     shared_font_relocated = false;
     lock = nullptr;
     notification_event = nullptr;
diff --git a/src/core/hle/service/apt/bcfnt/bcfnt.cpp b/src/core/hle/service/apt/bcfnt/bcfnt.cpp
index 57eb39d75..6d2474702 100644
--- a/src/core/hle/service/apt/bcfnt/bcfnt.cpp
+++ b/src/core/hle/service/apt/bcfnt/bcfnt.cpp
@@ -78,7 +78,8 @@ void RelocateSharedFont(Kernel::SharedPtr<Kernel::SharedMemory> shared_font, VAd
             memcpy(&cmap, data, sizeof(cmap));
 
             // Relocate the offsets in the CMAP section
-            cmap.next_cmap_offset += offset;
+            if (cmap.next_cmap_offset != 0)
+                cmap.next_cmap_offset += offset;
 
             memcpy(data, &cmap, sizeof(cmap));
         } else if (memcmp(section_header.magic, "CWDH", 4) == 0) {
@@ -86,7 +87,8 @@ void RelocateSharedFont(Kernel::SharedPtr<Kernel::SharedMemory> shared_font, VAd
             memcpy(&cwdh, data, sizeof(cwdh));
 
             // Relocate the offsets in the CWDH section
-            cwdh.next_cwdh_offset += offset;
+            if (cwdh.next_cwdh_offset != 0)
+                cwdh.next_cwdh_offset += offset;
 
             memcpy(data, &cwdh, sizeof(cwdh));
         } else if (memcmp(section_header.magic, "TGLP", 4) == 0) {
diff --git a/src/core/hle/service/frd/frd.cpp b/src/core/hle/service/frd/frd.cpp
index 76ecda8b7..7ad7798da 100644
--- a/src/core/hle/service/frd/frd.cpp
+++ b/src/core/hle/service/frd/frd.cpp
@@ -6,6 +6,7 @@
 #include "common/logging/log.h"
 #include "common/string_util.h"
 #include "core/hle/ipc.h"
+#include "core/hle/ipc_helpers.h"
 #include "core/hle/result.h"
 #include "core/hle/service/frd/frd.h"
 #include "core/hle/service/frd/frd_a.h"
@@ -105,6 +106,48 @@ void GetMyScreenName(Service::Interface* self) {
     LOG_WARNING(Service_FRD, "(STUBBED) called");
 }
 
+void UnscrambleLocalFriendCode(Service::Interface* self) {
+    const size_t scrambled_friend_code_size = 12;
+    const size_t friend_code_size = 8;
+
+    IPC::RequestParser rp(Kernel::GetCommandBuffer(), 0x1C, 1, 2);
+    const u32 friend_code_count = rp.Pop<u32>();
+    size_t in_buffer_size;
+    const VAddr scrambled_friend_codes = rp.PopStaticBuffer(&in_buffer_size, false);
+    ASSERT_MSG(in_buffer_size == (friend_code_count * scrambled_friend_code_size),
+               "Wrong input buffer size");
+
+    size_t out_buffer_size;
+    VAddr unscrambled_friend_codes = rp.PeekStaticBuffer(0, &out_buffer_size);
+    ASSERT_MSG(out_buffer_size == (friend_code_count * friend_code_size),
+               "Wrong output buffer size");
+
+    for (u32 current = 0; current < friend_code_count; ++current) {
+        // TODO(B3N30): Unscramble the codes and compare them against the friend list
+        //              Only write 0 if the code isn't in friend list, otherwise write the
+        //              unscrambled one
+        //
+        // Code for unscrambling (should be compared to HW):
+        // std::array<u16, 6> scambled_friend_code;
+        // Memory::ReadBlock(scrambled_friend_codes+(current*scrambled_friend_code_size),
+        // scambled_friend_code.data(), scrambled_friend_code_size); std::array<u16, 4>
+        // unscrambled_friend_code; unscrambled_friend_code[0] = scambled_friend_code[0] ^
+        // scambled_friend_code[5]; unscrambled_friend_code[1] = scambled_friend_code[1] ^
+        // scambled_friend_code[5]; unscrambled_friend_code[2] = scambled_friend_code[2] ^
+        // scambled_friend_code[5]; unscrambled_friend_code[3] = scambled_friend_code[3] ^
+        // scambled_friend_code[5];
+
+        u64 result = 0ull;
+        Memory::WriteBlock(unscrambled_friend_codes + (current * sizeof(result)), &result,
+                           sizeof(result));
+    }
+
+    LOG_WARNING(Service_FRD, "(STUBBED) called");
+    IPC::RequestBuilder rb = rp.MakeBuilder(1, 2);
+    rb.Push(RESULT_SUCCESS);
+    rb.PushStaticBuffer(unscrambled_friend_codes, out_buffer_size, 0);
+}
+
 void SetClientSdkVersion(Service::Interface* self) {
     u32* cmd_buff = Kernel::GetCommandBuffer();
 
diff --git a/src/core/hle/service/frd/frd.h b/src/core/hle/service/frd/frd.h
index e61940ea0..66a87c8cd 100644
--- a/src/core/hle/service/frd/frd.h
+++ b/src/core/hle/service/frd/frd.h
@@ -96,6 +96,19 @@ void GetMyFriendKey(Service::Interface* self);
 void GetMyScreenName(Service::Interface* self);
 
 /**
+ * FRD::UnscrambleLocalFriendCode service function
+ *  Inputs:
+ *      1 : Friend code count
+ *      2 : ((count * 12) << 14) | 0x402
+ *      3 : Pointer to encoded friend codes. Each is 12 bytes large
+ *      64 : ((count * 8) << 14) | 2
+ *      65 : Pointer to write decoded local friend codes to. Each is 8 bytes large.
+ *  Outputs:
+ *      1 : Result of function, 0 on success, otherwise error code
+ */
+void UnscrambleLocalFriendCode(Service::Interface* self);
+
+/**
  * FRD::SetClientSdkVersion service function
  *  Inputs:
  *      1 : Used SDK Version
diff --git a/src/core/hle/service/frd/frd_u.cpp b/src/core/hle/service/frd/frd_u.cpp
index 496f29ca9..6970ff768 100644
--- a/src/core/hle/service/frd/frd_u.cpp
+++ b/src/core/hle/service/frd/frd_u.cpp
@@ -36,7 +36,7 @@ const Interface::FunctionInfo FunctionTable[] = {
     {0x00190042, nullptr, "GetFriendFavoriteGame"},
     {0x001A00C4, nullptr, "GetFriendInfo"},
     {0x001B0080, nullptr, "IsIncludedInFriendList"},
-    {0x001C0042, nullptr, "UnscrambleLocalFriendCode"},
+    {0x001C0042, UnscrambleLocalFriendCode, "UnscrambleLocalFriendCode"},
     {0x001D0002, nullptr, "UpdateGameModeDescription"},
     {0x001E02C2, nullptr, "UpdateGameMode"},
     {0x001F0042, nullptr, "SendInvitation"},