1 files changed, 140 insertions, 25 deletions

diff --git a/src/core/hle/service/ns/pl_u.cpp b/src/core/hle/service/ns/pl_u.cpp
index bad27894a..fd11e79da 100644
--- a/src/core/hle/service/ns/pl_u.cpp
+++ b/src/core/hle/service/ns/pl_u.cpp
@@ -5,31 +5,97 @@
 #include "common/common_paths.h"
 #include "common/file_util.h"
 #include "core/core.h"
+#include "core/file_sys/romfs.h"
 #include "core/hle/ipc_helpers.h"
+#include "core/hle/service/filesystem/filesystem.h"
 #include "core/hle/service/ns/pl_u.h"
 
 namespace Service::NS {
 
+enum class FontArchives : u64 {
+    Extension = 0x0100000000000810,
+    Standard = 0x0100000000000811,
+    Korean = 0x0100000000000812,
+    ChineseTraditional = 0x0100000000000813,
+    ChineseSimple = 0x0100000000000814,
+};
+
 struct FontRegion {
     u32 offset;
     u32 size;
 };
 
+static constexpr std::array<std::pair<FontArchives, const char*>, 7> SHARED_FONTS{
+    std::make_pair(FontArchives::Standard, "nintendo_udsg-r_std_003.bfttf"),
+    std::make_pair(FontArchives::ChineseSimple, "nintendo_udsg-r_org_zh-cn_003.bfttf"),
+    std::make_pair(FontArchives::ChineseSimple, "nintendo_udsg-r_ext_zh-cn_003.bfttf"),
+    std::make_pair(FontArchives::ChineseTraditional, "nintendo_udjxh-db_zh-tw_003.bfttf"),
+    std::make_pair(FontArchives::Korean, "nintendo_udsg-r_ko_003.bfttf"),
+    std::make_pair(FontArchives::Extension, "nintendo_ext_003.bfttf"),
+    std::make_pair(FontArchives::Extension, "nintendo_ext2_003.bfttf")};
+
 // The below data is specific to shared font data dumped from Switch on f/w 2.2
 // Virtual address and offsets/sizes likely will vary by dump
 static constexpr VAddr SHARED_FONT_MEM_VADDR{0x00000009d3016000ULL};
+static constexpr u32 EXPECTED_RESULT{
+    0x7f9a0218}; // What we expect the decrypted bfttf first 4 bytes to be
+static constexpr u32 EXPECTED_MAGIC{
+    0x36f81a1e}; // What we expect the encrypted bfttf first 4 bytes to be
 static constexpr u64 SHARED_FONT_MEM_SIZE{0x1100000};
-static constexpr std::array<FontRegion, 6> SHARED_FONT_REGIONS{
-    FontRegion{0x00000008, 0x001fe764}, FontRegion{0x001fe774, 0x00773e58},
-    FontRegion{0x009725d4, 0x0001aca8}, FontRegion{0x0098d284, 0x00369cec},
-    FontRegion{0x00cf6f78, 0x0039b858}, FontRegion{0x010927d8, 0x00019e80},
-};
+static constexpr FontRegion EMPTY_REGION{0, 0};
+std::vector<FontRegion>
+    SHARED_FONT_REGIONS{}; // Automatically populated based on shared_fonts dump or system archives
+
+const FontRegion& GetSharedFontRegion(size_t index) {
+    if (index >= SHARED_FONT_REGIONS.size() || SHARED_FONT_REGIONS.empty()) {
+        // No font fallback
+        return EMPTY_REGION;
+    }
+    return SHARED_FONT_REGIONS.at(index);
+}
 
 enum class LoadState : u32 {
     Loading = 0,
     Done = 1,
 };
 
+void DecryptSharedFont(const std::vector<u32>& input, std::vector<u8>& output, size_t& offset) {
+    ASSERT_MSG(offset + (input.size() * sizeof(u32)) < SHARED_FONT_MEM_SIZE,
+               "Shared fonts exceeds 17mb!");
+    ASSERT_MSG(input[0] == EXPECTED_MAGIC, "Failed to derive key, unexpected magic number");
+
+    const u32 KEY = input[0] ^ EXPECTED_RESULT; // Derive key using an inverse xor
+    std::vector<u32> transformed_font(input.size());
+    // TODO(ogniK): Figure out a better way to do this
+    std::transform(input.begin(), input.end(), transformed_font.begin(),
+                   [&KEY](u32 font_data) { return Common::swap32(font_data ^ KEY); });
+    transformed_font[1] = Common::swap32(transformed_font[1]) ^ KEY; // "re-encrypt" the size
+    std::memcpy(output.data() + offset, transformed_font.data(),
+                transformed_font.size() * sizeof(u32));
+    offset += transformed_font.size() * sizeof(u32);
+}
+
+static u32 GetU32Swapped(const u8* data) {
+    u32 value;
+    std::memcpy(&value, data, sizeof(value));
+    return Common::swap32(value); // Helper function to make BuildSharedFontsRawRegions a bit nicer
+}
+
+void BuildSharedFontsRawRegions(const std::vector<u8>& input) {
+    unsigned cur_offset = 0; // As we can derive the xor key we can just populate the offsets based
+                             // on the shared memory dump
+    for (size_t i = 0; i < SHARED_FONTS.size(); i++) {
+        // Out of shared fonts/Invalid font
+        if (GetU32Swapped(input.data() + cur_offset) != EXPECTED_RESULT)
+            break;
+        const u32 KEY = GetU32Swapped(input.data() + cur_offset) ^
+                        EXPECTED_MAGIC; // Derive key withing inverse xor
+        const u32 SIZE = GetU32Swapped(input.data() + cur_offset + 4) ^ KEY;
+        SHARED_FONT_REGIONS.push_back(FontRegion{cur_offset + 8, SIZE});
+        cur_offset += SIZE + 8;
+    }
+}
+
 PL_U::PL_U() : ServiceFramework("pl:u") {
     static const FunctionInfo functions[] = {
         {0, &PL_U::RequestLoad, "RequestLoad"},
@@ -40,26 +106,78 @@ PL_U::PL_U() : ServiceFramework("pl:u") {
         {5, &PL_U::GetSharedFontInOrderOfPriority, "GetSharedFontInOrderOfPriority"},
     };
     RegisterHandlers(functions);
-
     // Attempt to load shared font data from disk
-    const std::string filepath{FileUtil::GetUserPath(FileUtil::UserPath::SysDataDir) + SHARED_FONT};
-    FileUtil::CreateFullPath(filepath); // Create path if not already created
-    FileUtil::IOFile file(filepath, "rb");
-
-    shared_font = std::make_shared<std::vector<u8>>(SHARED_FONT_MEM_SIZE);
-    if (file.IsOpen()) {
-        // Read shared font data
-        ASSERT(file.GetSize() == SHARED_FONT_MEM_SIZE);
-        file.ReadBytes(shared_font->data(), shared_font->size());
+    const auto nand = FileSystem::GetSystemNANDContents();
+    // Rebuild shared fonts from data ncas
+    if (nand->HasEntry(static_cast<u64>(FontArchives::Standard),
+                       FileSys::ContentRecordType::Data)) {
+        size_t offset = 0;
+        shared_font = std::make_shared<std::vector<u8>>(SHARED_FONT_MEM_SIZE);
+        for (auto font : SHARED_FONTS) {
+            const auto nca =
+                nand->GetEntry(static_cast<u64>(font.first), FileSys::ContentRecordType::Data);
+            if (!nca) {
+                LOG_ERROR(Service_NS, "Failed to find {:016X}! Skipping",
+                          static_cast<u64>(font.first));
+                continue;
+            }
+            const auto romfs = nca->GetRomFS();
+            if (!romfs) {
+                LOG_ERROR(Service_NS, "{:016X} has no RomFS! Skipping",
+                          static_cast<u64>(font.first));
+                continue;
+            }
+            const auto extracted_romfs = FileSys::ExtractRomFS(romfs);
+            if (!extracted_romfs) {
+                LOG_ERROR(Service_NS, "Failed to extract RomFS for {:016X}! Skipping",
+                          static_cast<u64>(font.first));
+                continue;
+            }
+            const auto font_fp = extracted_romfs->GetFile(font.second);
+            if (!font_fp) {
+                LOG_ERROR(Service_NS, "{:016X} has no file \"{}\"! Skipping",
+                          static_cast<u64>(font.first), font.second);
+                continue;
+            }
+            std::vector<u32> font_data_u32(font_fp->GetSize() / sizeof(u32));
+            font_fp->ReadBytes<u32>(font_data_u32.data(), font_fp->GetSize());
+            // We need to be BigEndian as u32s for the xor encryption
+            std::transform(font_data_u32.begin(), font_data_u32.end(), font_data_u32.begin(),
+                           Common::swap32);
+            FontRegion region{
+                static_cast<u32>(offset + 8),
+                static_cast<u32>((font_data_u32.size() * sizeof(u32)) -
+                                 8)}; // Font offset and size do not account for the header
+            DecryptSharedFont(font_data_u32, *shared_font, offset);
+            SHARED_FONT_REGIONS.push_back(region);
+        }
     } else {
-        LOG_WARNING(Service_NS, "Unable to load shared font: {}", filepath);
+        const std::string filepath{FileUtil::GetUserPath(FileUtil::UserPath::SysDataDir) +
+                                   SHARED_FONT};
+        // Create path if not already created
+        if (!FileUtil::CreateFullPath(filepath)) {
+            LOG_ERROR(Service_NS, "Failed to create sharedfonts path \"{}\"!", filepath);
+            return;
+        }
+        FileUtil::IOFile file(filepath, "rb");
+
+        shared_font = std::make_shared<std::vector<u8>>(
+            SHARED_FONT_MEM_SIZE); // Shared memory needs to always be allocated and a fixed size
+        if (file.IsOpen()) {
+            // Read shared font data
+            ASSERT(file.GetSize() == SHARED_FONT_MEM_SIZE);
+            file.ReadBytes(shared_font->data(), shared_font->size());
+            BuildSharedFontsRawRegions(*shared_font);
+        } else {
+            LOG_WARNING(Service_NS, "Unable to load shared font: {}", filepath);
+        }
     }
 }
 
 void PL_U::RequestLoad(Kernel::HLERequestContext& ctx) {
     IPC::RequestParser rp{ctx};
     const u32 shared_font_type{rp.Pop<u32>()};
-
+    // Games don't call this so all fonts should be loaded
     LOG_DEBUG(Service_NS, "called, shared_font_type={}", shared_font_type);
     IPC::ResponseBuilder rb{ctx, 2};
     rb.Push(RESULT_SUCCESS);
@@ -82,7 +200,7 @@ void PL_U::GetSize(Kernel::HLERequestContext& ctx) {
     LOG_DEBUG(Service_NS, "called, font_id={}", font_id);
     IPC::ResponseBuilder rb{ctx, 3};
     rb.Push(RESULT_SUCCESS);
-    rb.Push<u32>(SHARED_FONT_REGIONS[font_id].size);
+    rb.Push<u32>(GetSharedFontRegion(font_id).size);
 }
 
 void PL_U::GetSharedMemoryAddressOffset(Kernel::HLERequestContext& ctx) {
@@ -92,14 +210,10 @@ void PL_U::GetSharedMemoryAddressOffset(Kernel::HLERequestContext& ctx) {
     LOG_DEBUG(Service_NS, "called, font_id={}", font_id);
     IPC::ResponseBuilder rb{ctx, 3};
     rb.Push(RESULT_SUCCESS);
-    rb.Push<u32>(SHARED_FONT_REGIONS[font_id].offset);
+    rb.Push<u32>(GetSharedFontRegion(font_id).offset);
 }
 
 void PL_U::GetSharedMemoryNativeHandle(Kernel::HLERequestContext& ctx) {
-    // TODO(bunnei): This is a less-than-ideal solution to load a RAM dump of the Switch shared
-    // font data. This (likely) relies on exact address, size, and offsets from the original
-    // dump. In the future, we need to replace this with a more robust solution.
-
     // Map backing memory for the font data
     Core::CurrentProcess()->vm_manager.MapMemoryBlock(
         SHARED_FONT_MEM_VADDR, shared_font, 0, SHARED_FONT_MEM_SIZE, Kernel::MemoryState::Shared);
@@ -128,8 +242,9 @@ void PL_U::GetSharedFontInOrderOfPriority(Kernel::HLERequestContext& ctx) {
     // TODO(ogniK): Have actual priority order
     for (size_t i = 0; i < SHARED_FONT_REGIONS.size(); i++) {
         font_codes.push_back(static_cast<u32>(i));
-        font_offsets.push_back(SHARED_FONT_REGIONS[i].offset);
-        font_sizes.push_back(SHARED_FONT_REGIONS[i].size);
+        auto region = GetSharedFontRegion(i);
+        font_offsets.push_back(region.offset);
+        font_sizes.push_back(region.size);
     }
 
     ctx.WriteBuffer(font_codes, 0);