Boot: Unify the ELF and DOL code paths

They're essentially the same. To achieve this, this commit unifies
DolReader and ElfReader into a common interface for boot executable
readers, so the only remaining difference between ELF and DOL is
how which volume is inserted.

Source/Core/Core/Boot/DolReader.cpp

@@ -0,0 +1,116 @@
+// Copyright 2008 Dolphin Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#include "Core/Boot/DolReader.h"
+
+#include <cstring>
+#include <string>
+#include <vector>
+
+#include "Common/FileUtil.h"
+#include "Common/Swap.h"
+#include "Core/HW/Memmap.h"
+
+DolReader::DolReader(const std::vector<u8>& buffer) : BootExecutableReader(buffer)
+{
+  m_is_valid = Initialize(buffer);
+}
+
+DolReader::DolReader(const std::string& filename) : BootExecutableReader(filename)
+{
+  m_is_valid = Initialize(m_bytes);
+}
+
+DolReader::~DolReader() = default;
+
+bool DolReader::Initialize(const std::vector<u8>& buffer)
+{
+  if (buffer.size() < sizeof(SDolHeader))
+    return false;
+
+  memcpy(&m_dolheader, buffer.data(), sizeof(SDolHeader));
+
+  // swap memory
+  u32* p = (u32*)&m_dolheader;
+  for (size_t i = 0; i < (sizeof(SDolHeader) / sizeof(u32)); i++)
+    p[i] = Common::swap32(p[i]);
+
+  const u32 HID4_pattern = Common::swap32(0x7c13fba6);
+  const u32 HID4_mask = Common::swap32(0xfc1fffff);
+
+  m_is_wii = false;
+
+  m_text_sections.reserve(DOL_NUM_TEXT);
+  for (int i = 0; i < DOL_NUM_TEXT; ++i)
+  {
+    if (m_dolheader.textSize[i] != 0)
+    {
+      if (buffer.size() < m_dolheader.textOffset[i] + m_dolheader.textSize[i])
+        return false;
+
+      const u8* text_start = &buffer[m_dolheader.textOffset[i]];
+      m_text_sections.emplace_back(text_start, &text_start[m_dolheader.textSize[i]]);
+
+      for (unsigned int j = 0; !m_is_wii && j < (m_dolheader.textSize[i] / sizeof(u32)); ++j)
+      {
+        u32 word = ((u32*)text_start)[j];
+        if ((word & HID4_mask) == HID4_pattern)
+          m_is_wii = true;
+      }
+    }
+    else
+    {
+      // Make sure that m_text_sections indexes match header indexes
+      m_text_sections.emplace_back();
+    }
+  }
+
+  m_data_sections.reserve(DOL_NUM_DATA);
+  for (int i = 0; i < DOL_NUM_DATA; ++i)
+  {
+    if (m_dolheader.dataSize[i] != 0)
+    {
+      if (buffer.size() < m_dolheader.dataOffset[i] + m_dolheader.dataSize[i])
+        return false;
+
+      const u8* data_start = &buffer[m_dolheader.dataOffset[i]];
+      m_data_sections.emplace_back(data_start, &data_start[m_dolheader.dataSize[i]]);
+    }
+    else
+    {
+      // Make sure that m_data_sections indexes match header indexes
+      m_data_sections.emplace_back();
+    }
+  }
+
+  return true;
+}
+
+bool DolReader::LoadIntoMemory(bool only_in_mem1) const
+{
+  if (!m_is_valid)
+    return false;
+
+  // load all text (code) sections
+  for (size_t i = 0; i < m_text_sections.size(); ++i)
+    if (!m_text_sections[i].empty() &&
+        !(only_in_mem1 &&
+          m_dolheader.textAddress[i] + m_text_sections[i].size() >= Memory::REALRAM_SIZE))
+    {
+      Memory::CopyToEmu(m_dolheader.textAddress[i], m_text_sections[i].data(),
+                        m_text_sections[i].size());
+    }
+
+  // load all data sections
+  for (size_t i = 0; i < m_data_sections.size(); ++i)
+    if (!m_data_sections[i].empty() &&
+        !(only_in_mem1 &&
+          m_dolheader.dataAddress[i] + m_data_sections[i].size() >= Memory::REALRAM_SIZE))
+    {
+      Memory::CopyToEmu(m_dolheader.dataAddress[i], m_data_sections[i].data(),
+                        m_data_sections[i].size());
+    }
+
+  return true;
+}