1 files changed, 312 insertions, 0 deletions

diff --git a/src/core/loader/ncch.cpp b/src/core/loader/ncch.cpp
new file mode 100644
index 000000000..60505bdfa
--- /dev/null
+++ b/src/core/loader/ncch.cpp
@@ -0,0 +1,312 @@
+// Copyright 2014 Citra Emulator Project
+// Licensed under GPLv2
+// Refer to the license.txt file included.
+
+#include <memory>
+
+#include "common/file_util.h"
+
+#include "core/loader/ncch.h"
+#include "core/hle/kernel/kernel.h"
+#include "core/mem_map.h"
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+// Loader namespace
+
+namespace Loader {
+
+static const int kMaxSections   = 8;        ///< Maximum number of sections (files) in an ExeFs
+static const int kBlockSize     = 0x200;    ///< Size of ExeFS blocks (in bytes)
+
+/**
+ * Get the decompressed size of an LZSS compressed ExeFS file
+ * @param buffer Buffer of compressed file
+ * @param size Size of compressed buffer
+ * @return Size of decompressed buffer
+ */
+u32 LZSS_GetDecompressedSize(u8* buffer, u32 size) {
+    u32 offset_size = *(u32*)(buffer + size - 4);
+    return offset_size + size;
+}
+
+/**
+ * Decompress ExeFS file (compressed with LZSS)
+ * @param compressed Compressed buffer
+ * @param compressed_size Size of compressed buffer
+ * @param decompressed Decompressed buffer
+ * @param decompressed_size Size of decompressed buffer
+ * @return True on success, otherwise false
+ */
+bool LZSS_Decompress(u8* compressed, u32 compressed_size, u8* decompressed, u32 decompressed_size) {
+    u8* footer = compressed + compressed_size - 8;
+    u32 buffer_top_and_bottom = *(u32*)footer;
+    u32 i, j;
+    u32 out = decompressed_size;
+    u32 index = compressed_size - ((buffer_top_and_bottom >> 24) & 0xFF);
+    u8 control;
+    u32 stop_index = compressed_size - (buffer_top_and_bottom & 0xFFFFFF);
+
+    memset(decompressed, 0, decompressed_size);
+    memcpy(decompressed, compressed, compressed_size);
+
+    while(index > stop_index) {
+        control = compressed[--index];
+
+        for(i = 0; i < 8; i++) {
+            if(index <= stop_index)
+                break;
+            if(index <= 0)
+                break;
+            if(out <= 0)
+                break;
+
+            if(control & 0x80) {
+                // Check if compression is out of bounds
+                if(index < 2) {
+                    return false;
+                }
+                index -= 2;
+
+                u32 segment_offset = compressed[index] | (compressed[index + 1] << 8);
+                u32 segment_size = ((segment_offset >> 12) & 15) + 3;
+                segment_offset &= 0x0FFF;
+                segment_offset += 2;
+
+                // Check if compression is out of bounds
+                if(out < segment_size) {
+                    return false;
+                }
+                for(j = 0; j < segment_size; j++) {
+                    u8 data;
+                    // Check if compression is out of bounds
+                    if(out + segment_offset >= decompressed_size) {
+                        return false;
+                    }
+                    data  = decompressed[out + segment_offset];
+                    decompressed[--out] = data;
+                }
+            } else {
+                // Check if compression is out of bounds
+                if(out < 1) {
+                    return false;
+                }
+                decompressed[--out] = compressed[--index];
+            }
+            control <<= 1;
+        }
+    }
+    return true;
+}
+
+////////////////////////////////////////////////////////////////////////////////////////////////////
+// AppLoader_NCCH class
+
+/// AppLoader_NCCH constructor
+AppLoader_NCCH::AppLoader_NCCH(const std::string& filename) {
+    this->filename = filename;
+    is_loaded = false;
+    is_compressed = false;
+    entry_point = 0;
+    ncch_offset = 0;
+    exefs_offset = 0;
+}
+
+/// AppLoader_NCCH destructor
+AppLoader_NCCH::~AppLoader_NCCH() {
+    if (file.IsOpen())
+        file.Close();
+}
+
+/**
+ * Loads .code section into memory for booting
+ * @return ResultStatus result of function
+ */
+ResultStatus AppLoader_NCCH::LoadExec() {
+    if (!is_loaded) 
+        return ResultStatus::ErrorNotLoaded;
+
+    ResultStatus res;
+    code = ReadCode(res);
+
+    if (ResultStatus::Success == res) {
+        Memory::WriteBlock(entry_point, &code[0], code.size());
+        Kernel::LoadExec(entry_point);
+    }
+    return res;
+}
+
+/**
+ * Reads an application ExeFS section of an NCCH file into AppLoader (e.g. .code, .logo, etc.)
+ * @param name Name of section to read out of NCCH file
+ * @param buffer Vector to read data into
+ * @param error ResultStatus result of function
+ * @return Reference to buffer of data that was read
+ */
+const std::vector<u8>& AppLoader_NCCH::LoadSectionExeFS(const char* name, std::vector<u8>& buffer, 
+    ResultStatus& error) {
+    // Iterate through the ExeFs archive until we find the .code file...
+    for (int i = 0; i < kMaxSections; i++) {
+        // Load the specified section...
+        if (strcmp((const char*)exefs_header.section[i].name, name) == 0) {
+            INFO_LOG(LOADER, "ExeFS section %d:", i);
+            INFO_LOG(LOADER, "    name:   %s", exefs_header.section[i].name);
+            INFO_LOG(LOADER, "    offset: 0x%08X", exefs_header.section[i].offset);
+            INFO_LOG(LOADER, "    size:   0x%08X", exefs_header.section[i].size);
+
+            s64 section_offset = (exefs_header.section[i].offset + exefs_offset + 
+                sizeof(ExeFs_Header) + ncch_offset);
+            file.Seek(section_offset, 0);
+
+            // Section is compressed...
+            if (i == 0 && is_compressed) {
+                // Read compressed .code section...
+                std::unique_ptr<u8[]> temp_buffer(new u8[exefs_header.section[i].size]);
+                file.ReadBytes(&temp_buffer[0], exefs_header.section[i].size);
+
+                // Decompress .code section...
+                u32 decompressed_size = LZSS_GetDecompressedSize(&temp_buffer[0], 
+                    exefs_header.section[i].size);
+                buffer.resize(decompressed_size);
+                if (!LZSS_Decompress(&temp_buffer[0], exefs_header.section[i].size, &buffer[0],
+                    decompressed_size)) {
+                    error = ResultStatus::ErrorInvalidFormat;
+                    return buffer;
+                }
+            // Section is uncompressed...
+            } else {
+                buffer.resize(exefs_header.section[i].size);
+                file.ReadBytes(&buffer[0], exefs_header.section[i].size);
+            }
+            error = ResultStatus::Success;
+            return buffer;
+        }
+    }
+    error = ResultStatus::ErrorNotUsed;
+    return buffer;
+} 
+
+/**
+ * Loads an NCCH file (e.g. from a CCI, or the first NCCH in a CXI)
+ * @param error_string Pointer to string to put error message if an error has occurred
+ * @todo Move NCSD parsing out of here and create a separate function for loading these
+ * @return True on success, otherwise false
+ */
+ResultStatus AppLoader_NCCH::Load() {
+    INFO_LOG(LOADER, "Loading NCCH file %s...", filename.c_str());
+
+    if (is_loaded)
+        return ResultStatus::ErrorAlreadyLoaded;
+
+    file = File::IOFile(filename, "rb");
+
+    if (file.IsOpen()) {
+        file.ReadBytes(&ncch_header, sizeof(NCCH_Header));
+
+        // Skip NCSD header and load first NCCH (NCSD is just a container of NCCH files)...
+        if (0 == memcmp(&ncch_header.magic, "NCSD", 4)) {
+            WARN_LOG(LOADER, "Only loading the first (bootable) NCCH within the NCSD file!");
+            ncch_offset = 0x4000;
+            file.Seek(ncch_offset, 0);
+            file.ReadBytes(&ncch_header, sizeof(NCCH_Header));
+        }
+        
+        // Verify we are loading the correct file type...
+        if (0 != memcmp(&ncch_header.magic, "NCCH", 4))
+            return ResultStatus::ErrorInvalidFormat;
+
+        // Read ExHeader...
+
+        file.ReadBytes(&exheader_header, sizeof(ExHeader_Header));
+
+        is_compressed = (exheader_header.codeset_info.flags.flag & 1) == 1;
+        entry_point = exheader_header.codeset_info.text.address;
+
+        INFO_LOG(LOADER, "Name:            %s", exheader_header.codeset_info.name);
+        INFO_LOG(LOADER, "Code compressed: %s", is_compressed ? "yes" : "no");
+        INFO_LOG(LOADER, "Entry point:     0x%08X", entry_point);
+
+        // Read ExeFS...
+
+        exefs_offset = ncch_header.exefs_offset * kBlockSize;
+        u32 exefs_size = ncch_header.exefs_size * kBlockSize;
+
+        INFO_LOG(LOADER, "ExeFS offset:    0x%08X", exefs_offset);
+        INFO_LOG(LOADER, "ExeFS size:      0x%08X", exefs_size);
+
+        file.Seek(exefs_offset + ncch_offset, 0);
+        file.ReadBytes(&exefs_header, sizeof(ExeFs_Header));
+
+        is_loaded = true; // Set state to loaded
+
+        LoadExec(); // Load the executable into memory for booting
+
+        return ResultStatus::Success;
+    }
+    return ResultStatus::Error;
+}
+
+/**
+ * Get the code (typically .code section) of the application
+ * @param error ResultStatus result of function
+ * @return Reference to code buffer
+ */
+const std::vector<u8>& AppLoader_NCCH::ReadCode(ResultStatus& error) {
+    return LoadSectionExeFS(".code", code, error);
+}
+
+/**
+ * Get the icon (typically icon section) of the application
+ * @param error ResultStatus result of function
+ * @return Reference to icon buffer
+ */
+const std::vector<u8>& AppLoader_NCCH::ReadIcon(ResultStatus& error) {
+    return LoadSectionExeFS("icon", icon, error);
+}
+
+/**
+ * Get the banner (typically banner section) of the application
+ * @param error ResultStatus result of function
+ * @return Reference to banner buffer
+ */
+const std::vector<u8>& AppLoader_NCCH::ReadBanner(ResultStatus& error) {
+    return LoadSectionExeFS("banner", banner, error);
+}
+
+/**
+ * Get the logo (typically logo section) of the application
+ * @param error ResultStatus result of function
+ * @return Reference to logo buffer
+ */
+const std::vector<u8>& AppLoader_NCCH::ReadLogo(ResultStatus& error) {
+    return LoadSectionExeFS("logo", logo, error);
+}
+
+/**
+ * Get the RomFs archive of the application
+ * @param error ResultStatus result of function
+ * @return Reference to RomFs archive buffer
+ */
+const std::vector<u8>& AppLoader_NCCH::ReadRomFS(ResultStatus& error) {
+    // Check if the NCCH has a RomFS...
+    if (ncch_header.romfs_offset != 0 && ncch_header.romfs_size != 0) {
+        u32 romfs_offset = ncch_offset + (ncch_header.romfs_offset * kBlockSize) + 0x1000;
+        u32 romfs_size = (ncch_header.romfs_size * kBlockSize) - 0x1000;
+
+        INFO_LOG(LOADER, "RomFS offset:    0x%08X", romfs_offset);
+        INFO_LOG(LOADER, "RomFS size:      0x%08X", romfs_size);
+
+        romfs.resize(romfs_size);
+
+        file.Seek(romfs_offset, 0);
+        file.ReadBytes(&romfs[0], romfs_size);
+
+        error = ResultStatus::Success;
+        return romfs;
+    } else {
+        NOTICE_LOG(LOADER, "RomFS unused");
+    }
+    error = ResultStatus::ErrorNotUsed;
+    return romfs;
+}
+
+} // namespace Loader