1 files changed, 185 insertions, 0 deletions
diff --git a/src/core/loader/nso.cpp b/src/core/loader/nso.cpp
new file mode 100644
index 000000000..b1b57d0c0
--- /dev/null
+++ b/src/core/loader/nso.cpp
@@ -0,0 +1,185 @@
+// Copyright 2017 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#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"
+
+namespace Loader {
+
+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, RoData, Data (in that order)
+    u32_le bss_size;
+    INSERT_PADDING_BYTES(0x1c);
+    std::array<u32_le, 3> segments_compressed_size;
+};
+static_assert(sizeof(NsoHeader) == 0x6c, "NsoHeader has incorrect size.");
+
+struct ModHeader {
+    u32_le magic;
+    u32_le dynamic_offset;
+    u32_le bss_start_offset;
+    u32_le bss_end_offset;
+    u32_le eh_frame_hdr_start_offset;
+    u32_le eh_frame_hdr_end_offset;
+    u32_le module_offset; // Offset to runtime-generated module object. typically equal to .bss base
+};
+static_assert(sizeof(ModHeader) == 0x1c, "ModHeader has incorrect size.");
+
+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;
+}
+
+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(
+        reinterpret_cast<const char*>(compressed_data.data()),
+        reinterpret_cast<char*>(uncompressed_data.data()), compressed_size, header.size);
+
+    ASSERT_MSG(bytes_uncompressed == header.size && bytes_uncompressed == uncompressed_data.size(),
+               "%d != %d != %d", bytes_uncompressed, header.size, uncompressed_data.size());
+
+    return uncompressed_data;
+}
+
+static constexpr u32 PageAlignSize(u32 size) {
+    return (size + Memory::PAGE_MASK) & ~Memory::PAGE_MASK;
+}
+
+VAddr AppLoader_NSO::LoadNso(const std::string& path, VAddr load_base, bool relocate) {
+    FileUtil::IOFile file(path, "rb");
+    if (!file.IsOpen()) {
+        return {};
+    }
+
+    // Read NSO header
+    NsoHeader nso_header{};
+    file.Seek(0, SEEK_SET);
+    if (sizeof(NsoHeader) != file.ReadBytes(&nso_header, sizeof(NsoHeader))) {
+        return {};
+    }
+    if (nso_header.magic != MakeMagic('N', 'S', 'O', '0')) {
+        return {};
+    }
+
+    // Build program image
+    Kernel::SharedPtr<Kernel::CodeSet> codeset = Kernel::CodeSet::Create("", 0);
+    std::vector<u8> program_image;
+    for (int i = 0; i < nso_header.segments.size(); ++i) {
+        std::vector<u8> data =
+            ReadSegment(file, nso_header.segments[i], nso_header.segments_compressed_size[i]);
+        program_image.resize(nso_header.segments[i].location);
+        program_image.insert(program_image.end(), data.begin(), data.end());
+        codeset->segments[i].addr = nso_header.segments[i].location;
+        codeset->segments[i].offset = nso_header.segments[i].location;
+        codeset->segments[i].size = PageAlignSize(static_cast<u32>(data.size()));
+    }
+
+    // MOD header pointer is at .text offset + 4
+    u32 module_offset;
+    std::memcpy(&module_offset, program_image.data() + 4, sizeof(u32));
+
+    // Read MOD header
+    ModHeader mod_header{};
+    u32 bss_size{Memory::PAGE_SIZE}; // Default .bss to page size if MOD0 section doesn't exist
+    std::memcpy(&mod_header, program_image.data() + module_offset, sizeof(ModHeader));
+    const bool has_mod_header{mod_header.magic == MakeMagic('M', 'O', 'D', '0')};
+    if (has_mod_header) {
+        // Resize program image to include .bss section and page align each section
+        bss_size = PageAlignSize(mod_header.bss_end_offset - mod_header.bss_start_offset);
+        codeset->data.size += bss_size;
+    }
+    const u32 image_size{PageAlignSize(static_cast<u32>(program_image.size()) + bss_size)};
+    program_image.resize(image_size);
+
+    // Relocate symbols if there was a proper MOD header - This must happen after the image has been
+    // loaded into memory
+    if (has_mod_header && relocate) {
+        Relocate(program_image, module_offset + mod_header.dynamic_offset, load_base);
+    }
+
+    // Load codeset for current process
+    codeset->name = path;
+    codeset->memory = std::make_shared<std::vector<u8>>(std::move(program_image));
+    Kernel::g_current_process->LoadModule(codeset, load_base);
+
+    return load_base + image_size;
+}
+
+ResultStatus AppLoader_NSO::Load(Kernel::SharedPtr<Kernel::Process>& process) {
+    if (is_loaded) {
+        return ResultStatus::ErrorAlreadyLoaded;
+    }
+    if (!file.IsOpen()) {
+        return ResultStatus::Error;
+    }
+
+    // Load and relocate "rtld" NSO
+    static constexpr VAddr base_addr{Memory::PROCESS_IMAGE_VADDR};
+    process = Kernel::Process::Create("main");
+    VAddr next_base_addr{LoadNso(filepath, base_addr)};
+    if (!next_base_addr) {
+        return ResultStatus::ErrorInvalidFormat;
+    }
+
+    // Load and relocate remaining submodules
+    for (const auto& module_name : {"main", "sdk", "subsdk0", "subsdk1"}) {
+        const std::string module_path =
+            filepath.substr(0, filepath.find_last_of("/\\")) + "/" + module_name;
+        next_base_addr = LoadNso(module_path, next_base_addr);
+        if (!next_base_addr) {
+            LOG_WARNING(Loader, "failed to find load module: %s", module_name);
+        }
+    }
+
+    process->svc_access_mask.set();
+    process->address_mappings = default_address_mappings;
+    process->resource_limit =
+        Kernel::ResourceLimit::GetForCategory(Kernel::ResourceLimitCategory::APPLICATION);
+    process->Run(base_addr, 48, Kernel::DEFAULT_STACK_SIZE);
+
+    ResolveImports();
+
+    is_loaded = true;
+    return ResultStatus::Success;
+}
+
+} // namespace Loader