ArmEbPkg/Sec/ModuleEntryPoint.S

   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
  18 .text
  19 .align 3
  20
  21 .globl ASM_PFX(CEntryPoint)
  22 .globl ASM_PFX(_ModuleEntryPoint)
  23
  24 ASM_PFX(_ModuleEntryPoint):
  25
  26   //
  27   // Set stack based on PCD values. Need to do it this way to make C code work
  28   // when it runs from FLASH.
  29   //
  30   LoadConstantToReg (FixedPcdGet32(PcdPrePiStackBase) ,r2)    /* stack base arg2  */
  31   LoadConstantToReg (FixedPcdGet32(PcdPrePiStackSize) ,r3)    /* stack size arg3  */
  32   add     r4, r2, r3
  33
  34   //Enter SVC mode and set up SVC stack pointer
  35   mov     r0,#0x13|0x80|0x40
  36   msr     CPSR_c,r0
  37   sub     r4, r4, #0x400
  38   mov     r13,r4
  39
  40   // Call C entry point
  41   LoadConstantToReg (FixedPcdGet32(PcdMemorySize) ,r1)    /* memory size arg1          */
  42   LoadConstantToReg (FixedPcdGet32(PcdMemoryBase) ,r0)    /* memory size arg0         */
  43
  44   blx      ASM_PFX(CEntryPoint) /* Assume C code is ARM      */
  45
  46 ShouldNeverGetHere:
  47   /* _CEntryPoint should never return */
  48   b       ShouldNeverGetHere
  49
  50