ArmPkg/Include/AsmMacroIoLibV8.h

   1 /** @file
   2   Macros to work around lack of Clang support for LDR register, =expr
   3
   4   Copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
   5   Portions copyright (c) 2011 - 2014, ARM Ltd. All rights reserved.<BR>
   6
   7   This program and the accompanying materials
   8   are licensed and made available under the terms and conditions of the BSD License
   9   which accompanies this distribution.  The full text of the license may be found at
  10   http://opensource.org/licenses/bsd-license.php
  11
  12   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  13   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  14
  15 **/
  16
  17
  18 #ifndef __MACRO_IO_LIBV8_H__
  19 #define __MACRO_IO_LIBV8_H__
  20
  21 // CurrentEL : 0xC = EL3; 8 = EL2; 4 = EL1
  22 // This only selects between EL1 and EL2, else we die.
  23 // Provide the Macro with a safe temp xreg to use.
  24 #define EL1_OR_EL2(SAFE_XREG)        \
  25         mrs    SAFE_XREG, CurrentEL ;\
  26         cmp    SAFE_XREG, #0x8      ;\
  27         b.eq   2f                   ;\
  28         cmp    SAFE_XREG, #0x4      ;\
  29         b.ne   .                    ;// We should never get here
  30 // EL1 code starts here
  31
  32 // CurrentEL : 0xC = EL3; 8 = EL2; 4 = EL1
  33 // This only selects between EL1 and EL2 and EL3, else we die.
  34 // Provide the Macro with a safe temp xreg to use.
  35 #define EL1_OR_EL2_OR_EL3(SAFE_XREG) \
  36         mrs    SAFE_XREG, CurrentEL ;\
  37         cmp    SAFE_XREG, #0xC      ;\
  38         b.eq   3f                   ;\
  39         cmp    SAFE_XREG, #0x8      ;\
  40         b.eq   2f                   ;\
  41         cmp    SAFE_XREG, #0x4      ;\
  42         b.ne   .                    ;// We should never get here
  43 // EL1 code starts here
  44 #if defined(__clang__)
  45
  46 // load x0 with _Data
  47 #define LoadConstant(_Data)              \
  48   ldr  x0, 1f                          ; \
  49   b    2f                              ; \
  50 .align(8)                              ; \
  51 1:                                       \
  52   .8byte (_Data)                       ; \
  53 2:
  54
  55 // load _Reg with _Data
  56 #define LoadConstantToReg(_Data, _Reg)    \
  57   ldr  _Reg, 1f                         ; \
  58   b    2f                               ; \
  59 .align(8)                               ; \
  60 1:                                        \
  61   .8byte (_Data)                        ; \
  62 2:
  63
  64 #elif defined (__GNUC__)
  65
  66 #define LoadConstant(Data) \
  67   ldr  x0, =Data
  68
  69 #define LoadConstantToReg(Data, Reg) \
  70   ldr  Reg, =Data
  71
  72 #endif // __GNUC__
  73
  74 #endif // __MACRO_IO_LIBV8_H__
  75