ArmPlatformPkg/PrePi: Add support for PrePi module

[mirror_edk2.git] / ArmPlatformPkg / PrePi / ModuleEntryPoint.asm

//\r
//  Copyright (c) 2011, ARM Limited. All rights reserved.\r
//\r
//  This program and the accompanying materials\r
//  are licensed and made available under the terms and conditions of the BSD License\r
//  which accompanies this distribution.  The full text of the license may be found at\r
//  http://opensource.org/licenses/bsd-license.php\r
//\r
//  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
//  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
//\r
//\r
\r
#include <AsmMacroIoLib.h>\r
#include <Base.h>\r
#include <Library/PcdLib.h>\r
#include <AutoGen.h>\r
\r
  INCLUDE AsmMacroIoLib.inc\r
  \r
  IMPORT  CEntryPoint\r
  EXPORT  _ModuleEntryPoint\r
\r
  PRESERVE8\r
  AREA    PrePiCoreEntryPoint, CODE, READONLY\r
  \r
StartupAddr        DCD      CEntryPoint\r
\r
_ModuleEntryPoint\r
  // Identify CPU ID\r
  mrc   p15, 0, r0, c0, c0, 5\r
  and   r0, #0xf\r
\r
_UefiMemoryBase\r
#if FixedPcdGet32(PcdStandalone)\r
  // Compute Top of System Memory\r
  LoadConstantToReg (FixedPcdGet32(PcdSystemMemoryBase), r1)\r
  LoadConstantToReg (FixedPcdGet32(PcdSystemMemorySize), r2)\r
  add   r1, r1, r2      // r1 = SystemMemoryTop = PcdSystemMemoryBase + PcdSystemMemorySize\r
#else\r
  // If it is not a Standalone, we must compute the top of the UEFI memory with the base of the FD\r
  LoadConstantToReg (FixedPcdGet32(PcdNormalFdBaseAddress), r1)\r
#endif\r
\r
  // Compute Base of UEFI Memory\r
  LoadConstantToReg (FixedPcdGet32(PcdSystemMemoryUefiRegionSize), r2)\r
  sub   r1, r1, r2      // r1 = SystemMemoryTop - PcdSystemMemoryUefiRegionSize = UefiMemoryBase\r
\r
_SetupStack\r
  // Compute Base of Normal stacks for CPU Cores\r
  LoadConstantToReg (FixedPcdGet32(PcdCPUCoresNonSecStackSize), r2)\r
  mul   r3, r0, r2      // r3 = core_id * stack_size = offset from the stack base\r
  sub   sp, r1, r3      // r3 = UefiMemoryBase - StackOffset = TopOfStack\r
\r
  // Only allocate memory in top of the primary core stack\r
  cmp   r0, #0\r
  bne   _PrepareArguments\r
\r
_AllocateGlobalPrePiVariables\r
  // Reserve top of the stack for Global PEI Variables (eg: PeiServicesTablePointer)\r
  LoadConstantToReg (FixedPcdGet32(PcdPeiGlobalVariableSize), r4)\r
  // The reserved place must be 8-bytes aligned for pushing 64-bit variable on the stack\r
  and   r5, r4, #7\r
  rsb   r5, r5, #8\r
  add   r4, r4, r5\r
  sub   sp, sp, r4\r
\r
_PrepareArguments\r
  // Pass the StackBase to the C Entrypoint (UefiMemoryBase - StackSize - StackOffset)\r
  sub   r2, r1, r2\r
  sub   r2, r3\r
  // Move sec startup address into a data register\r
  // Ensure we're jumping to FV version of the code (not boot remapped alias)\r
  ldr   r3, StartupAddr\r
\r
  // jump to PrePiCore C code\r
  //    r0 = core_id\r
  //    r1 = UefiMemoryBase\r
  //    r2 = StackBase\r
  blx   r3\r
\r
  END\r