audk/ArmPlatformPkg/PrePi/ModuleEntryPoint.S

85 lines
2.8 KiB
ArmAsm
Executable File

//
// Copyright (c) 2011, ARM Limited. All rights reserved.
//
// This program and the accompanying materials
// are licensed and made available under the terms and conditions of the BSD License
// which accompanies this distribution. The full text of the license may be found at
// http://opensource.org/licenses/bsd-license.php
//
// THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
// WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
//
//
#include <AsmMacroIoLib.h>
#include <Base.h>
#include <Library/PcdLib.h>
#include <AutoGen.h>
#start of the code section
.text
.align 3
#global symbols referenced by this module
GCC_ASM_IMPORT(CEntryPoint)
StartupAddr: .word CEntryPoint
#make _ModuleEntryPoint as global
GCC_ASM_EXPORT(_ModuleEntryPoint)
ASM_PFX(_ModuleEntryPoint):
// Identify CPU ID
mrc p15, 0, r0, c0, c0, 5
and r0, #0xf
_UefiMemoryBase:
#if FixedPcdGet32(PcdStandalone)
// Compute Top of System Memory
LoadConstantToReg (FixedPcdGet32(PcdSystemMemoryBase), r1)
LoadConstantToReg (FixedPcdGet32(PcdSystemMemorySize), r2)
add r1, r1, r2 // r1 = SystemMemoryTop = PcdSystemMemoryBase + PcdSystemMemorySize
#else
// If it is not a Standalone, we must compute the top of the UEFI memory with the base of the FD
LoadConstantToReg (FixedPcdGet32(PcdNormalFdBaseAddress), r1)
#endif
// Compute Base of UEFI Memory
LoadConstantToReg (FixedPcdGet32(PcdSystemMemoryUefiRegionSize), r2)
sub r1, r1, r2 // r1 = SystemMemoryTop - PcdSystemMemoryUefiRegionSize = UefiMemoryBase
_SetupStack:
// Compute Base of Normal stacks for CPU Cores
LoadConstantToReg (FixedPcdGet32(PcdCPUCoresNonSecStackSize), r2)
mul r3, r0, r2 // r3 = core_id * stack_size = offset from the stack base
sub sp, r1, r3 // r3 = UefiMemoryBase - StackOffset = TopOfStack
// Only allocate memory in top of the primary core stack
cmp r0, #0
bne _PrepareArguments
_AllocateGlobalPeiVariables:
// Reserve top of the stack for Global PEI Variables (eg: PeiServicesTablePointer)
LoadConstantToReg (FixedPcdGet32(PcdPeiGlobalVariableSize), r4)
// The reserved place must be 8-bytes aligned for pushing 64-bit variable on the stack
and r5, r4, #7
rsb r5, r5, #8
add r4, r4, r5
sub sp, sp, r4
_PrepareArguments:
// Pass the StackBase to the C Entrypoint (UefiMemoryBase - StackSize - StackOffset)
sub r2, r1, r2
sub r2, r3
// Move sec startup address into a data register
// Ensure we're jumping to FV version of the code (not boot remapped alias)
ldr r3, StartupAddr
// jump to PrePiCore C code
// r0 = core_id
// r1 = UefiMemoryBase
// r2 = StackBase
blx r3