ArmPlatformPkg/PrePeiCore/PrePeiCoreEntryPoint.asm

   1 //
   2 //  Copyright (c) 2011, ARM Limited. All rights reserved.
   3 //
   4 //  This program and the accompanying materials
   5 //  are licensed and made available under the terms and conditions of the BSD License
   6 //  which accompanies this distribution.  The full text of the license may be found at
   7 //  http://opensource.org/licenses/bsd-license.php
   8 //
   9 //  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  10 //  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  11 //
  12 //
  13
  14 #include <AsmMacroIoLib.h>
  15 #include <Base.h>
  16 #include <Library/PcdLib.h>
  17 #include <AutoGen.h>
  18
  19   INCLUDE AsmMacroIoLib.inc
  20
  21   IMPORT  CEntryPoint
  22   EXPORT  _ModuleEntryPoint
  23
  24   PRESERVE8
  25   AREA    PrePeiCoreEntryPoint, CODE, READONLY
  26
  27 StartupAddr        DCD      CEntryPoint
  28
  29 _ModuleEntryPoint
  30   // Identify CPU ID
  31   mrc   p15, 0, r0, c0, c0, 5
  32   and   r0, #0xf
  33
  34 _SetupStack
  35   // Setup Stack for the 4 CPU cores
  36   LoadConstantToReg (FixedPcdGet32(PcdCPUCoresNonSecStackBase), r1)
  37   LoadConstantToReg (FixedPcdGet32(PcdCPUCoresNonSecStackSize), r2)
  38
  39   mov   r3, r0              // r3 = core_id
  40   mul   r3, r3, r2          // r3 = core_id * stack_size = offset from the stack base
  41   add   r3, r3, r1          // r3 = stack_base + offset
  42   add   r3, r3, r2, LSR #1  // r3 = stack_offset + (stack_size/2) <-- the top half is for the heap
  43   mov   sp, r3
  44
  45   // Only allocate memory in top of the primary core stack
  46   cmp   r0, #0
  47   bne   _PrepareArguments
  48
  49 _AllocateGlobalPeiVariables
  50   // Reserve top of the stack for Global PEI Variables (eg: PeiServicesTablePointer)
  51   LoadConstantToReg (FixedPcdGet32(PcdPeiGlobalVariableSize), r1)
  52   sub   sp, sp, r1
  53
  54 _PrepareArguments
  55   // The PEI Core Entry Point has been computed by GenFV and stored in the second entry of the Reset Vector
  56   LoadConstantToReg (FixedPcdGet32(PcdNormalFvBaseAddress), r2)
  57   add   r2, r2, #4
  58   ldr   r1, [r2]
  59
  60   // move sec startup address into a data register
  61   // ensure we're jumping to FV version of the code (not boot remapped alias)
  62   ldr   r2, StartupAddr
  63
  64   // jump to PrePeiCore C code
  65   //    r0 = core_id
  66   //    r1 = pei_core_address
  67   blx   r2
  68
  69   END