ArmPlatformPkg/ArmJunoPkg/Library/ArmJunoLib/Arm/ArmJunoHelper.S

   1 /** @file
   2 *
   3 *  Copyright (c) 2013-2014, ARM Limited. All rights reserved.
   4 *
   5 *  This program and the accompanying materials
   6 *  are licensed and made available under the terms and conditions of the BSD License
   7 *  which accompanies this distribution.  The full text of the license may be found at
   8 *  http://opensource.org/licenses/bsd-license.php
   9 *
  10 *  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11 *  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12 *
  13 **/
  14
  15 #include <AsmMacroIoLibV8.h>
  16 #include <Library/ArmLib.h>
  17
  18 .text
  19 .align 3
  20
  21 GCC_ASM_EXPORT(ArmPlatformPeiBootAction)
  22 GCC_ASM_EXPORT(ArmPlatformGetCorePosition)
  23 GCC_ASM_EXPORT(ArmPlatformGetPrimaryCoreMpId)
  24 GCC_ASM_EXPORT(ArmPlatformIsPrimaryCore)
  25
  26 GCC_ASM_IMPORT(_gPcd_FixedAtBuild_PcdArmPrimaryCoreMask)
  27
  28
  29 PrimaryCoreMpid:  .word    0x0
  30
  31 //
  32 // Return the core position from the value of its MpId register
  33 //
  34 // This function returns the core position from the position 0 in the processor.
  35 // This function might be called from assembler before any stack is set.
  36 //
  37 // @return   Return the core position
  38 //
  39 //UINTN
  40 //ArmPlatformGetCorePosition (
  41 //  IN UINTN MpId
  42 //  );
  43 // With this function: CorePos = (ClusterId * 2) + CoreId
  44 ASM_PFX(ArmPlatformGetCorePosition):
  45   and   r1, r0, #ARM_CORE_MASK
  46   and   r0, r0, #ARM_CLUSTER_MASK
  47   add   r0, r1, r0, LSR #7
  48   bx    lr
  49
  50 //
  51 // Return the MpId of the primary core
  52 //
  53 // This function returns the MpId of the primary core.
  54 // This function might be called from assembler before any stack is set.
  55 //
  56 // @return   Return the MpId of the primary core
  57 //
  58 //UINTN
  59 //ArmPlatformGetPrimaryCoreMpId (
  60 //  VOID
  61 //  );
  62 ASM_PFX(ArmPlatformGetPrimaryCoreMpId):
  63   ldr   r0, =PrimaryCoreMpid
  64   ldr   r0, [r0]
  65   bx    lr
  66
  67 //
  68 // Return a non-zero value if the callee is the primary core
  69 //
  70 // This function returns a non-zero value if the callee is the primary core.
  71 // The primary core is the core responsible to initialize the hardware and run UEFI.
  72 // This function might be called from assembler before any stack is set.
  73 //
  74 //  @return   Return a non-zero value if the callee is the primary core.
  75 //
  76 //UINTN
  77 //ArmPlatformIsPrimaryCore (
  78 //  IN UINTN MpId
  79 //  );
  80 ASM_PFX(ArmPlatformIsPrimaryCore):
  81   LoadConstantToReg (_gPcd_FixedAtBuild_PcdArmPrimaryCoreMask, r1)
  82   ldr   r1, [r1]
  83   and   r0, r0, r1
  84
  85   ldr   r1, =PrimaryCoreMpid
  86   ldr   r1, [r1]
  87
  88   cmp   r0, r1
  89   moveq r0, #1
  90   movne r0, #0
  91   bx    lr
  92
  93 //
  94 // First platform specific function to be called in the PEI phase
  95 //
  96 // This function is actually the first function called by the PrePi
  97 // or PrePeiCore modules. It allows to retrieve arguments passed to
  98 // the UEFI firmware through the CPU registers.
  99 //
 100 ASM_PFX(ArmPlatformPeiBootAction):
 101   // The trusted firmware passes the primary CPU MPID through r0 register.
 102   // Save it in a variable.
 103   ldr  r1, =PrimaryCoreMpid
 104   str  r0, [r1]
 105   bx   lr