4 files changed, 340 insertions, 0 deletions

diff --git a/src/core/loader/loader.cpp b/src/core/loader/loader.cpp
index be719d74c..d309e7c9e 100644
--- a/src/core/loader/loader.cpp
+++ b/src/core/loader/loader.cpp
@@ -10,6 +10,7 @@
 #include "core/loader/3dsx.h"
 #include "core/loader/elf.h"
 #include "core/loader/ncch.h"
+#include "core/loader/nso.h"
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////
 
@@ -32,6 +33,7 @@ FileType IdentifyFile(FileUtil::IOFile& file) {
     CHECK_TYPE(THREEDSX)
     CHECK_TYPE(ELF)
     CHECK_TYPE(NCCH)
+    CHECK_TYPE(NSO)
 
 #undef CHECK_TYPE
 
@@ -115,6 +117,10 @@ static std::unique_ptr<AppLoader> GetFileLoader(FileUtil::IOFile&& file, FileTyp
     case FileType::CCI:
         return std::make_unique<AppLoader_NCCH>(std::move(file), filepath);
 
+    // NX NSO file format.
+    case FileType::NSO:
+        return std::make_unique<AppLoader_NSO>(std::move(file), filename, filepath);
+
     default:
         return nullptr;
     }
diff --git a/src/core/loader/loader.h b/src/core/loader/loader.h
index 48bbf687d..79a3bd498 100644
--- a/src/core/loader/loader.h
+++ b/src/core/loader/loader.h
@@ -32,6 +32,7 @@ enum class FileType {
     CIA,
     ELF,
     THREEDSX, // 3DSX
+    NSO,
 };
 
 /**
diff --git a/src/core/loader/nso.cpp b/src/core/loader/nso.cpp
new file mode 100644
index 000000000..ca8c59cd5
--- /dev/null
+++ b/src/core/loader/nso.cpp
@@ -0,0 +1,295 @@
+// Copyright 2017 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <map>
+#include <string>
+#include <vector>
+#include <lz4.h>
+
+#include "common/logging/log.h"
+#include "common/swap.h"
+#include "core/hle/kernel/process.h"
+#include "core/hle/kernel/resource_limit.h"
+#include "core/loader/nso.h"
+#include "core/memory.h"
+
+using Kernel::CodeSet;
+using Kernel::SharedPtr;
+
+namespace Loader {
+
+FileType AppLoader_NSO::IdentifyType(FileUtil::IOFile& file) {
+    u32 magic = 0;
+    file.Seek(0, SEEK_SET);
+    if (1 != file.ReadArray<u32>(&magic, 1))
+        return FileType::Error;
+
+    if (MakeMagic('N', 'S', 'O', '0') == magic)
+        return FileType::NSO;
+
+    return FileType::Error;
+}
+
+struct NsoSegmentHeader {
+    u32_le offset;
+    u32_le location;
+    u32_le size;
+    u32_le alignment;
+};
+static_assert(sizeof(NsoSegmentHeader) == 0x10, "NsoSegmentHeader has incorrect size.");
+
+struct NsoHeader {
+    u32_le magic;
+    INSERT_PADDING_BYTES(0xc);
+    std::array<NsoSegmentHeader, 3> segments; // Text, Data, RoData (in that order)
+    INSERT_PADDING_BYTES(0x20);
+    std::array<u32_le, 3> segments_compressed_size;
+};
+
+static_assert(sizeof(NsoHeader) == 0x6c, "NsoHeader has incorrect size.");
+
+static std::vector<u8> ReadSegment(FileUtil::IOFile& file, const NsoSegmentHeader& header,
+                                   int compressed_size) {
+    std::vector<u8> compressed_data;
+    compressed_data.resize(compressed_size);
+
+    file.Seek(header.offset, SEEK_SET);
+    if (compressed_size != file.ReadBytes(compressed_data.data(), compressed_size)) {
+        LOG_CRITICAL(Loader, "Failed to read %d NSO LZ4 compressed bytes", compressed_size);
+        return {};
+    }
+
+    std::vector<u8> uncompressed_data;
+    uncompressed_data.resize(header.size);
+    const int bytes_uncompressed =
+        LZ4_decompress_safe_partial(reinterpret_cast<const char*>(compressed_data.data()),
+                                    reinterpret_cast<char*>(uncompressed_data.data()),
+                                    compressed_size, header.size, header.size);
+
+    ASSERT_MSG(bytes_uncompressed == header.size, "%d != %d", bytes_uncompressed, header.size);
+
+    return uncompressed_data;
+}
+
+struct Symbol {
+    Symbol(std::string&& name, u64 value) : name(std::move(name)), value(value) {}
+    std::string name;
+    u64 value;
+};
+
+struct Import {
+    VAddr ea;
+    s64 addend;
+};
+
+enum class RelocationType : u32 {
+    ABS64 = 257,
+    GLOB_DAT = 1025,
+    JUMP_SLOT = 1026,
+    RELATIVE = 1027
+};
+
+enum DynamicType : u32 {
+    DT_NULL = 0,
+    DT_PLTRELSZ = 2,
+    DT_STRTAB = 5,
+    DT_SYMTAB = 6,
+    DT_RELA = 7,
+    DT_RELASZ = 8,
+    DT_STRSZ = 10,
+    DT_JMPREL = 23,
+};
+
+void WriteRelocations(const std::vector<Symbol>& symbols, VAddr loadbase, u64 roff, u64 size,
+                      bool is_jump_relocation, std::map<std::string, Import>& imports,
+                      std::map<std::string, VAddr>& exports) {
+    for (u64 i = 0; i < size; i += 0x18) {
+        VAddr addr = loadbase + roff + i;
+        u64 offset = Memory::Read64(addr);
+        u64 info = Memory::Read64(addr + 8);
+        u64 addend_unsigned = Memory::Read64(addr + 16);
+        s64 addend{};
+        std::memcpy(&addend, &addend_unsigned, sizeof(u64));
+
+        RelocationType rtype = static_cast<RelocationType>(info & 0xFFFFFFFF);
+        u32 rsym = static_cast<u32>(info >> 32);
+        VAddr ea = loadbase + offset;
+
+        const Symbol& symbol = symbols[rsym];
+
+        switch (rtype) {
+        case RelocationType::RELATIVE:
+            if (!symbol.name.empty()) {
+                exports[symbol.name] = loadbase + addend;
+            }
+            Memory::Write64(ea, loadbase + addend);
+            break;
+        case RelocationType::JUMP_SLOT:
+        case RelocationType::GLOB_DAT:
+            if (!symbol.value) {
+                imports[symbol.name] = {ea, 0};
+            } else {
+                exports[symbol.name] = symbol.value;
+                Memory::Write64(ea, symbol.value);
+            }
+            break;
+        case RelocationType::ABS64:
+            if (!symbol.value) {
+                imports[symbol.name] = {ea, addend};
+            } else {
+                exports[symbol.name] = symbol.value + addend;
+                Memory::Write64(ea, symbol.value + addend);
+            }
+            break;
+        default:
+            LOG_CRITICAL(Loader, "Unknown relocation type: %d", rtype);
+            break;
+        }
+    }
+}
+
+void Relocate(VAddr loadbase, std::map<std::string, Import>& imports,
+              std::map<std::string, VAddr>& exports) {
+    u32 modoff = Memory::Read32(loadbase + 4);
+    ASSERT_MSG(Memory::Read32(loadbase + modoff) == MakeMagic('M', 'O', 'D', '0'),
+               "Expected MOD section");
+
+    u64 dynoff = loadbase + modoff + Memory::Read32(loadbase + modoff + 4);
+    std::map<u64, u64> dynamic;
+    while (1) {
+        u64 tag = Memory::Read64(dynoff);
+        u64 value = Memory::Read64(dynoff + 8);
+        dynoff += 16;
+
+        if (tag == DT_NULL) {
+            break;
+        }
+        dynamic[tag] = value;
+    }
+
+    u64 strtabsize = dynamic[DT_STRSZ];
+    std::vector<u8> strtab;
+    strtab.resize(strtabsize);
+    Memory::ReadBlock(loadbase + dynamic[DT_STRTAB], strtab.data(), strtabsize);
+
+    VAddr addr = loadbase + dynamic[DT_SYMTAB];
+    std::vector<Symbol> symbols;
+    while (1) {
+        const u32 stname = Memory::Read32(addr);
+        const u16 stshndx = Memory::Read16(addr + 6);
+        const u64 stvalue = Memory::Read64(addr + 8);
+        addr += 24;
+
+        if (stname >= strtabsize) {
+            break;
+        }
+
+        std::string name = reinterpret_cast<char*>(&strtab[stname]);
+        if (stvalue) {
+            exports[name] = loadbase + stvalue;
+            symbols.emplace_back(std::move(name), loadbase + stvalue);
+        } else {
+            symbols.emplace_back(std::move(name), 0);
+        }
+    }
+
+    if (dynamic.find(DT_RELA) != dynamic.end()) {
+        WriteRelocations(symbols, loadbase, dynamic[DT_RELA], dynamic[DT_RELASZ], false, imports,
+                         exports);
+    }
+
+    if (dynamic.find(DT_JMPREL) != dynamic.end()) {
+        WriteRelocations(symbols, loadbase, dynamic[DT_JMPREL], dynamic[DT_PLTRELSZ], true, imports,
+                         exports);
+    }
+}
+
+static VAddr GetEntryPoint(const std::map<std::string, VAddr>& exports) {
+    // Find nnMain function, set entrypoint to that address
+    const auto& search = exports.find("nnMain");
+    if (search != exports.end()) {
+        return search->second;
+    }
+    return {};
+}
+
+static SharedPtr<CodeSet> LoadModule(const std::string& filepath, VAddr loadbase,
+                                     std::map<std::string, Import>& imports,
+                                     std::map<std::string, VAddr>& exports) {
+    FileUtil::IOFile file(filepath, "rb");
+
+    if (!file.IsOpen())
+        return {};
+
+    NsoHeader header{};
+    file.Seek(0, SEEK_SET);
+    if (sizeof(NsoHeader) != file.ReadBytes(&header, sizeof(NsoHeader)))
+        return {};
+
+    // Build program image
+    SharedPtr<CodeSet> codeset = CodeSet::Create("", 0);
+    std::vector<u8> program_image;
+    for (int i = 0; i < header.segments.size(); ++i) {
+        std::vector<u8> data =
+            ReadSegment(file, header.segments[i], header.segments_compressed_size[i]);
+        program_image.resize(header.segments[i].location);
+        program_image.insert(program_image.end(), data.begin(), data.end());
+        codeset->segments[i].addr = header.segments[i].location;
+        codeset->segments[i].offset = header.segments[i].location;
+        codeset->segments[i].size = (data.size() + Memory::PAGE_MASK) & ~Memory::PAGE_MASK;
+    }
+    program_image.resize((program_image.size() + Memory::PAGE_MASK) & ~Memory::PAGE_MASK);
+
+    codeset->name = filepath;
+    codeset->entrypoint = 0; // Set after relocation
+    codeset->memory = std::make_shared<std::vector<u8>>(std::move(program_image));
+
+    return codeset;
+}
+
+ResultStatus AppLoader_NSO::Load() {
+    if (is_loaded)
+        return ResultStatus::ErrorAlreadyLoaded;
+
+    if (!file.IsOpen())
+        return ResultStatus::Error;
+
+    static constexpr VAddr loadbase = 0x7100000000;
+    std::map<std::string, Import> imports;
+    std::map<std::string, VAddr> exports;
+
+    // Load and relocate "main" NSO
+    auto codeset = LoadModule(filepath, loadbase, imports, exports);
+    Kernel::g_current_process = Kernel::Process::Create(codeset);
+    Kernel::g_current_process->svc_access_mask.set();
+    Kernel::g_current_process->address_mappings = default_address_mappings;
+    Kernel::g_current_process->resource_limit =
+        Kernel::ResourceLimit::GetForCategory(Kernel::ResourceLimitCategory::APPLICATION);
+    Kernel::g_current_process->LoadModule(codeset, loadbase);
+    Relocate(loadbase, imports, exports);
+    codeset->entrypoint = GetEntryPoint(exports);
+    Kernel::g_current_process->Run(48, Kernel::DEFAULT_STACK_SIZE);
+
+    // Load and relocate "sdk" NSO
+    static constexpr VAddr sdkbase = 0x7200000000;
+    const std::string sdkpath = filepath.substr(0, filepath.find_last_of("/\\")) + "/sdk";
+    auto sdk_codeset = LoadModule(sdkpath, sdkbase, imports, exports);
+    Kernel::g_current_process->LoadModule(sdk_codeset, sdkbase);
+    Relocate(sdkbase, imports, exports);
+
+    // Resolve imports
+    for (const auto& import : imports) {
+        const auto& search = exports.find(import.first);
+        if (search != exports.end()) {
+            Memory::Write64(import.second.ea, search->second + import.second.addend);
+        } else {
+            LOG_CRITICAL(Loader, "Unresolved import: %s", import.first.c_str());
+        }
+    }
+
+    is_loaded = true;
+    return ResultStatus::Success;
+}
+
+} // namespace Loader
diff --git a/src/core/loader/nso.h b/src/core/loader/nso.h
new file mode 100644
index 000000000..39a9bd3d9
--- /dev/null
+++ b/src/core/loader/nso.h
@@ -0,0 +1,38 @@
+// Copyright 2017 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <string>
+#include "common/common_types.h"
+#include "common/file_util.h"
+#include "core/loader/loader.h"
+
+namespace Loader {
+
+/// Loads an NSO file
+class AppLoader_NSO final : public AppLoader {
+public:
+    AppLoader_NSO(FileUtil::IOFile&& file, std::string filename, std::string filepath)
+        : AppLoader(std::move(file)), filename(std::move(filename)), filepath(std::move(filepath)) {}
+
+    /**
+     * Returns the type of the file
+     * @param file FileUtil::IOFile open file
+     * @return FileType found, or FileType::Error if this loader doesn't know it
+     */
+    static FileType IdentifyType(FileUtil::IOFile& file);
+
+    FileType GetFileType() override {
+        return IdentifyType(file);
+    }
+
+    ResultStatus Load() override;
+
+private:
+    std::string filename;
+    std::string filepath;
+};
+
+} // namespace Loader