Loader: Add 3DSX support

1 files changed, 236 insertions, 0 deletions

diff --git a/src/core/loader/3dsx.cpp b/src/core/loader/3dsx.cpp
new file mode 100644
index 00000000..7ef14635
--- /dev/null
+++ b/src/core/loader/3dsx.cpp
@@ -0,0 +1,236 @@
+// Copyright 2014 Citra Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#include <algorithm>
+#include <vector>
+
+#include "core/file_sys/archive_romfs.h"
+#include "core/loader/elf.h"
+#include "core/loader/ncch.h"
+#include "core/hle/kernel/archive.h"
+#include "core/mem_map.h"
+
+#include "3dsx.h"
+
+
+namespace Loader {
+
+
+/** 
+ * File layout:
+ * - File header
+ * - Code, rodata and data relocation table headers
+ * - Code segment
+ * - Rodata segment
+ * - Loadable (non-BSS) part of the data segment
+ * - Code relocation table
+ * - Rodata relocation table
+ * - Data relocation table
+ *
+ * Memory layout before relocations are applied:
+ * [0..codeSegSize)             -> code segment
+ * [codeSegSize..rodataSegSize) -> rodata segment
+ * [rodataSegSize..dataSegSize) -> data segment
+ *
+ * Memory layout after relocations are applied: well, however the loader sets it up :)
+ * The entrypoint is always the start of the code segment.
+ * The BSS section must be cleared manually by the application.
+ */
+enum THREEDSX_Error {
+    ERROR_NONE = 0,
+    ERROR_READ = 1,
+    ERROR_FILE = 2,
+    ERROR_ALLOC = 3
+};
+static const u32 RELOCBUFSIZE = 512;
+
+// File header
+static const u32 THREEDSX_MAGIC = 0x58534433; // '3DSX'
+#pragma pack(1)
+struct THREEDSX_Header
+{
+    u32 magic;
+    u16 header_size, reloc_hdr_size;
+    u32 format_ver;
+    u32 flags;
+
+    // Sizes of the code, rodata and data segments +
+    // size of the BSS section (uninitialized latter half of the data segment)
+    u32 code_seg_size, rodata_seg_size, data_seg_size, bss_size;
+};
+
+// Relocation header: all fields (even extra unknown fields) are guaranteed to be relocation counts.
+struct THREEDSX_RelocHdr
+{
+    // # of absolute relocations (that is, fix address to post-relocation memory layout)
+    u32 cross_segment_absolute; 
+    // # of cross-segment relative relocations (that is, 32bit signed offsets that need to be patched)
+    u32 cross_segment_relative; 
+    // more?
+
+    // Relocations are written in this order:
+    // - Absolute relocations
+    // - Relative relocations
+};
+
+// Relocation entry: from the current pointer, skip X words and patch Y words
+struct THREEDSX_Reloc
+{
+    u16 skip, patch;
+};
+#pragma pack()
+
+struct THREEloadinfo
+{
+    u8* seg_ptrs[3]; // code, rodata & data
+    u32 seg_addrs[3];
+    u32 seg_sizes[3];
+};
+
+class THREEDSXReader {
+public:
+     static int Load3DSXFile(const std::string& filename, u32 base_addr);
+};
+
+static u32 TranslateAddr(u32 addr, THREEloadinfo *loadinfo, u32* offsets)
+{
+    if (addr < offsets[0])
+        return loadinfo->seg_addrs[0] + addr;
+    if (addr < offsets[1])
+        return loadinfo->seg_addrs[1] + addr - offsets[0];
+    return loadinfo->seg_addrs[2] + addr - offsets[1];
+}
+
+int THREEDSXReader::Load3DSXFile(const std::string& filename, u32 base_addr)
+{
+    FileUtil::IOFile file(filename, "rb");
+    if (!file.IsOpen()) {
+        return ERROR_FILE;
+    }
+    THREEDSX_Header hdr;
+    if (file.ReadBytes(&hdr, sizeof(hdr)) != sizeof(hdr))
+        return ERROR_READ;
+
+    THREEloadinfo loadinfo;
+    //loadinfo segments must be a multiple of 0x1000
+    loadinfo.seg_sizes[0] = (hdr.code_seg_size + 0xFFF) &~0xFFF;
+    loadinfo.seg_sizes[1] = (hdr.rodata_seg_size + 0xFFF) &~0xFFF;
+    loadinfo.seg_sizes[2] = (hdr.data_seg_size + 0xFFF) &~0xFFF;
+    u32 offsets[2] = { loadinfo.seg_sizes[0], loadinfo.seg_sizes[0] + loadinfo.seg_sizes[1] };
+    u32 data_load_size = (hdr.data_seg_size - hdr.bss_size + 0xFFF) &~0xFFF;
+    u32 bss_load_size = loadinfo.seg_sizes[2] - data_load_size;
+    u32 n_reloc_tables = hdr.reloc_hdr_size / 4;
+    std::vector<u8> all_mem(loadinfo.seg_sizes[0] + loadinfo.seg_sizes[1] + loadinfo.seg_sizes[2] + 3 * n_reloc_tables);
+
+    loadinfo.seg_addrs[0] = base_addr;
+    loadinfo.seg_addrs[1] = loadinfo.seg_addrs[0] + loadinfo.seg_sizes[0];
+    loadinfo.seg_addrs[2] = loadinfo.seg_addrs[1] + loadinfo.seg_sizes[1];
+    loadinfo.seg_ptrs[0] = &all_mem[0];
+    loadinfo.seg_ptrs[1] = loadinfo.seg_ptrs[0] + loadinfo.seg_sizes[0];
+    loadinfo.seg_ptrs[2] = loadinfo.seg_ptrs[1] + loadinfo.seg_sizes[1];
+
+    // Skip header for future compatibility
+    file.Seek(hdr.header_size, SEEK_SET);
+
+    // Read the relocation headers
+    u32* relocs = (u32*)(loadinfo.seg_ptrs[2] + hdr.data_seg_size);
+
+    for (u32 current_segment = 0; current_segment < 3; current_segment++) {
+        if (file.ReadBytes(&relocs[current_segment*n_reloc_tables], n_reloc_tables * 4) != n_reloc_tables * 4)
+            return ERROR_READ;
+    }
+
+    // Read the segments
+    if (file.ReadBytes(loadinfo.seg_ptrs[0], hdr.code_seg_size) != hdr.code_seg_size)
+        return ERROR_READ;
+    if (file.ReadBytes(loadinfo.seg_ptrs[1], hdr.rodata_seg_size) != hdr.rodata_seg_size)
+        return ERROR_READ;
+    if (file.ReadBytes(loadinfo.seg_ptrs[2], hdr.data_seg_size - hdr.bss_size) != hdr.data_seg_size - hdr.bss_size)
+        return ERROR_READ;
+
+    // BSS clear
+    memset((char*)loadinfo.seg_ptrs[2] + hdr.data_seg_size - hdr.bss_size, 0, hdr.bss_size);
+
+    // Relocate the segments
+    for (u32 current_segment = 0; current_segment < 3; current_segment++) {
+        for (u32 current_segment_reloc_table = 0; current_segment_reloc_table < n_reloc_tables; current_segment_reloc_table++) {
+            u32 n_relocs = relocs[current_segment*n_reloc_tables + current_segment_reloc_table];
+            if (current_segment_reloc_table >= 2) {
+                // We are not using this table - ignore it because we don't know what it dose
+                file.Seek(n_relocs*sizeof(THREEDSX_Reloc), SEEK_CUR);
+                continue;
+            }
+            static THREEDSX_Reloc reloc_table[RELOCBUFSIZE];
+
+            u32* pos = (u32*)loadinfo.seg_ptrs[current_segment];
+            u32* end_pos = pos + (loadinfo.seg_sizes[current_segment] / 4);
+
+            while (n_relocs) {
+                u32 remaining = std::min(RELOCBUFSIZE, n_relocs);
+                n_relocs -= remaining;
+
+                if (file.ReadBytes(reloc_table, remaining*sizeof(THREEDSX_Reloc)) != remaining*sizeof(THREEDSX_Reloc))
+                    return ERROR_READ;
+
+                for (u32 current_inprogress = 0; current_inprogress < remaining && pos < end_pos; current_inprogress++) {
+                    DEBUG_LOG(LOADER, "(t=%d,skip=%u,patch=%u)\n",
+                        current_segment_reloc_table, (u32)reloc_table[current_inprogress].skip, (u32)reloc_table[current_inprogress].patch);
+                    pos += reloc_table[current_inprogress].skip;
+                    s32 num_patches = reloc_table[current_inprogress].patch;
+                    while (0 < num_patches && pos < end_pos) {
+                        u32 in_addr = (char*)pos - (char*)&all_mem[0];
+                        u32 addr = TranslateAddr(*pos, &loadinfo, offsets);
+                        DEBUG_LOG(LOADER, "Patching %08X <-- rel(%08X,%d) (%08X)\n",
+                            base_addr + in_addr, addr, current_segment_reloc_table, *pos);
+                        switch (current_segment_reloc_table) {
+                        case 0: *pos = (addr); break;
+                        case 1: *pos = (addr - in_addr); break;
+                        default: break; //this should never happen
+                        }
+                        pos++;
+                        num_patches--;
+                    }
+                }
+            }
+        }
+    }
+
+    // Write the data
+    memcpy(Memory::GetPointer(base_addr), &all_mem[0], loadinfo.seg_sizes[0] + loadinfo.seg_sizes[1] + loadinfo.seg_sizes[2]);
+
+    DEBUG_LOG(LOADER, "CODE:   %u pages\n", loadinfo.seg_sizes[0] / 0x1000);
+    DEBUG_LOG(LOADER, "RODATA: %u pages\n", loadinfo.seg_sizes[1] / 0x1000);
+    DEBUG_LOG(LOADER, "DATA:   %u pages\n", data_load_size / 0x1000);
+    DEBUG_LOG(LOADER, "BSS:    %u pages\n", bss_load_size / 0x1000);
+
+    return ERROR_NONE;
+}
+
+    /// AppLoader_DSX constructor
+    AppLoader_THREEDSX::AppLoader_THREEDSX(const std::string& filename) : filename(filename) {
+    }
+
+    /// AppLoader_DSX destructor
+    AppLoader_THREEDSX::~AppLoader_THREEDSX() {
+    }
+
+    /**
+    * Loads a 3DSX file
+    * @return Success on success, otherwise Error
+    */
+    ResultStatus AppLoader_THREEDSX::Load() {
+        INFO_LOG(LOADER, "Loading 3DSX file %s...", filename.c_str());
+        FileUtil::IOFile file(filename, "rb");
+        if (file.IsOpen()) {
+
+            THREEDSXReader reader;
+            reader.Load3DSXFile(filename, 0x00100000);
+            Kernel::LoadExec(0x00100000);
+        } else {
+            return ResultStatus::Error;
+        }
+        return ResultStatus::Success;
+    }
+
+} // namespace Loader