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//
// 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>
.text
.align 3
# Global symbols referenced by this module
GCC_ASM_IMPORT(CEntryPoint)
GCC_ASM_EXPORT(_ModuleEntryPoint)
StartupAddr: .word CEntryPoint
ASM_PFX(_ModuleEntryPoint):
// Identify CPU ID
mrc p15, 0, r0, c0, c0, 5
and r0, #0xf
_SetSVCMode:
// Enter SVC mode
mov r1, #0x13|0x80|0x40
msr CPSR_c, r1
// Check if we can install the size at the top of the System Memory or if we need
// to install the stacks at the bottom of the Firmware Device (case the FD is located
// at the top of the DRAM)
_SetupStackPosition:
// Compute Top of System Memory
LoadConstantToReg (FixedPcdGet32(PcdSystemMemoryBase), r1)
LoadConstantToReg (FixedPcdGet32(PcdSystemMemorySize), r2)
add r1, r1, r2 // r1 = SystemMemoryTop = PcdSystemMemoryBase + PcdSystemMemorySize
// Calculate Top of the Firmware Device
LoadConstantToReg (FixedPcdGet32(PcdNormalFdBaseAddress), r2)
LoadConstantToReg (FixedPcdGet32(PcdNormalFdSize), r3)
add r3, r3, r2 // r4 = FdTop = PcdNormalFdBaseAddress + PcdNormalFdSize
// UEFI Memory Size (stacks are allocated in this region)
LoadConstantToReg (FixedPcdGet32(PcdSystemMemoryUefiRegionSize), r4)
//
// Reserve the memory for the UEFI region (contain stacks on its top)
//
// Calculate how much space there is between the top of the Firmware and the Top of the System Memory
subs r5, r1, r3 // r5 = SystemMemoryTop - FdTop
bmi _SetupStack // Jump if negative (FdTop > SystemMemoryTop)
cmp r5, r4
bge _SetupStack
// Case the top of stacks is the FdBaseAddress
mov r1, r2
_SetupStack:
// Compute Base of Normal stacks for CPU Cores
LoadConstantToReg (FixedPcdGet32(PcdCPUCoresNonSecStackSize), r5)
mul r3, r0, r5 // r3 = core_id * stack_size = offset from the stack base
sub sp, r1, r3 // r3 = (SystemMemoryTop|FdBaseAddress) - StackOffset = TopOfStack
// Calculate the Base of the UEFI Memory
sub r1, r1, r4
// Only allocate memory for global variables at top of the primary core stack
cmp r0, #0
bne _PrepareArguments
_AllocateGlobalPrePiVariables:
// 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:
// Move sec startup address into a data register
// Ensure we're jumping to FV version of the code (not boot remapped alias)
ldr r2, StartupAddr
// Jump to PrePiCore C code
// r0 = core_id
// r1 = UefiMemoryBase
blx r2
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