osfmk/i386/asm64.h

   1 /*
   2  * Copyright (c) 2006 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22
  23 /* Helper macros for 64-bit mode switching */
  24
  25 /*
  26  * Long jump to 64-bit space from 32-bit compatibility mode.
  27  */
  28 #define ENTER_64BIT_MODE()                      \
  29         .code32                                 ;\
  30         .byte   0xea    /* far jump longmode */ ;\
  31         .long   1f                              ;\
  32         .word   KERNEL64_CS                     ;\
  33         .code64                                 ;\
  34 1:
  35
  36 /*
  37  * Here in long mode but still running below 4G.
  38  * "Near" jump into uber-space.
  39  */
  40 #define ENTER_UBERSPACE()                       \
  41         mov     2f,%rax                         ;\
  42         jmp     *%rax                           ;\
  43 2:      .long   3f                              ;\
  44         .long   KERNEL_UBER_BASE_HI32           ;\
  45 3:
  46
  47 /*
  48  * Long jump to 32-bit compatibility mode from 64-bit space.
  49  */
  50 #define ENTER_COMPAT_MODE()                     \
  51         ljmp    *4f                             ;\
  52 4:      .long   5f                              ;\
  53         .word   KERNEL_CS                       ;\
  54         .code32                                 ;\
  55 5:
  56