BeagleBoardPkg/Library/BeagleBoardLib/BeagleBoardHelper.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 <BeagleBoard.h>
  18 #include <AutoGen.h>
  19
  20   INCLUDE AsmMacroIoLib.inc
  21
  22   EXPORT  ArmPlatformIsBootMemoryInitialized
  23   EXPORT  ArmPlatformInitializeBootMemory
  24
  25   PRESERVE8
  26   AREA    BeagleBoardHelper, CODE, READONLY
  27
  28 /**
  29   Called at the early stage of the Boot phase to know if the memory has already been initialized
  30
  31   Running the code from the reset vector does not mean we start from cold boot. In some case, we
  32   can go through this code with the memory already initialized.
  33   Because this function is called at the early stage, the implementation must not use the stack.
  34   Its implementation must probably done in assembly to ensure this requirement.
  35
  36   @return   Return a non zero value if initialized
  37
  38 **/
  39 ArmPlatformIsBootMemoryInitialized
  40   // The system memory is initialized by the BeagleBoard firmware
  41   mov   r0, #1
  42   bx    lr
  43
  44 /**
  45   Initialize the memory where the initial stacks will reside
  46
  47   This memory can contain the initial stacks (Secure and Secure Monitor stacks).
  48   In some platform, this region is already initialized and the implementation of this function can
  49   do nothing. This memory can also represent the Secure RAM.
  50   This function is called before the satck has been set up. Its implementation must ensure the stack
  51   pointer is not used (probably required to use assembly language)
  52
  53 **/
  54 ArmPlatformInitializeBootMemory
  55   // We must need to go into this function
  56   bx    lr
  57
  58   END