ArmEbPkg/Sec/ModuleEntryPoint.asm

   1 //------------------------------------------------------------------------------
   2 //
   3 // Copyright (c) 2008-2009 Apple Inc. All rights reserved.
   4 //
   5 // All rights reserved. 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 <AsmMacroIoLib.h>
  16 #include <Library/PcdLib.h>
  17 #include <AutoGen.h>
  18   INCLUDE AsmMacroIoLib.inc
  19
  20   IMPORT  CEntryPoint
  21   EXPORT  _ModuleEntryPoint
  22
  23   PRESERVE8
  24   AREA    ModuleEntryPoint, CODE, READONLY
  25
  26
  27 _ModuleEntryPoint
  28
  29
  30   //
  31   // Set stack based on PCD values. Need to do it this way to make C code work
  32   // when it runs from FLASH.
  33   //
  34   LoadConstantToReg (FixedPcdGet32(PcdPrePiStackBase) ,r2)    /* stack base arg2  */
  35   LoadConstantToReg (FixedPcdGet32(PcdPrePiStackSize) ,r3)    /* stack size arg3  */
  36   add     r4, r2, r3
  37
  38   //Enter SVC mode and set up SVC stack pointer
  39   mov     r0,#0x13|0x80|0x40
  40   msr     CPSR_c,r0
  41   mov     r13,r4
  42
  43   // Call C entry point
  44   LoadConstantToReg (FixedPcdGet32(PcdMemorySize) ,r1)    /* memory size arg1          */
  45   LoadConstantToReg (FixedPcdGet32(PcdMemoryBase) ,r0)    /* memory size arg0         */
  46   blx     CEntryPoint       /* Assume C code is thumb    */
  47
  48 ShouldNeverGetHere
  49   /* _CEntryPoint should never return */
  50   b       ShouldNeverGetHere
  51
  52   END
  53