text: /**
   * Copyright (c) 2012 by Lukas Heidemann <lukasheidemann@gmail.com>
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   *
   * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
   * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
   * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
   * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
   * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  #pragma once
  #include <stdint.h>
  
  // Fast Syscall MSR IDs
  #define SYSCALL_MSR_STAR    0xC0000081
  #define SYSCALL_MSR_LSTAR   0xC0000082
  #define SYSCALL_MSR_CSTAR   0xC0000083
  #define SYSCALL_MSR_SFMASK  0xC0000084
  
  // Default values for fast syscall MSRs
  #define SYSCALL_STAR        (((uint64_t) 0x8 << 32) | ((uint64_t) 0x18 << 48))
  #define SYSCALL_SFMASK      (1 << 9)
  
  /**
   * Initializes the processor's fast system call capabilities by writing
   * the related MSRs. The long-mode system call entry point is provided
   * by the kernel in the syscall_entry field of the header.
   */
  void syscall_init(void);
  