gdt.h

/*
 * Copyright (c) 2008-2014, Pedigree Developers
 *
 * Please see the CONTRIB file in the root of the source tree for a full
 * list of contributors.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */
 
#ifndef KERNEL_PROCESSOR_X64_GDT_H
#define KERNEL_PROCESSOR_X64_GDT_H
#include "pedigree/kernel/compiler.h"
#include "pedigree/kernel/processor/types.h"
 
#include <config.h>
 
struct X64TaskStateSegment;
 
class X64GdtManager {
 public:
  inline static X64GdtManager& instance() {
    return m_Instance;
  }
 
  void initialise(size_t processorCount) INITIALISATION_ONLY;
  static void initialiseProcessor() INITIALISATION_ONLY;
 
 private:
  X64GdtManager() INITIALISATION_ONLY;
  X64GdtManager(const X64GdtManager&);
  X64GdtManager& operator=(const X64GdtManager&);
  ~X64GdtManager();
 
  void setSegmentDescriptor(size_t index, uint64_t base, uint32_t limit, uint8_t flags,
                            uint8_t flags2);
  void setTssDescriptor(size_t index, uint64_t base) INITIALISATION_ONLY;
 
  void initialiseTss(X64TaskStateSegment* pTss) INITIALISATION_ONLY;
  void initialiseDoubleFaultTss(X64TaskStateSegment* pTss) INITIALISATION_ONLY;
 
  static void loadSegmentRegisters();
 
  struct segment_descriptor {
    uint16_t limit0;
    uint16_t base0;
    uint8_t base1;
    uint8_t flags;
    uint8_t flags_limit1;
    uint8_t base2;
  } PACKED;
 
  struct tss_descriptor {
    uint32_t base3;
    uint32_t res;
  };
 
  segment_descriptor* m_Gdt;
  size_t m_DescriptorCount;
 
  static X64GdtManager m_Instance;
};
 
#endif