audk/ArmPlatformPkg/PrePeiCore/AArch64/PrePeiCoreEntryPoint.S

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//
// Copyright (c) 2011-2014, 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 <AsmMacroIoLibV8.h>
#include <Base.h>
#include <Library/PcdLib.h>
#include <AutoGen.h>
.text
.align 3
GCC_ASM_IMPORT(CEntryPoint)
GCC_ASM_IMPORT(ArmPlatformGetCorePosition)
GCC_ASM_IMPORT(ArmPlatformIsPrimaryCore)
GCC_ASM_IMPORT(ArmReadMpidr)
GCC_ASM_IMPORT(ArmPlatformPeiBootAction)
GCC_ASM_EXPORT(_ModuleEntryPoint)
StartupAddr: .dword CEntryPoint
ASM_PFX(_ModuleEntryPoint):
// Do early platform specific actions
bl ASM_PFX(ArmPlatformPeiBootAction)
// NOTE: We could be booting from EL3, EL2 or EL1. Need to correctly detect
// and configure the system accordingly. EL2 is default if possible.
// If we started in EL3 we need to switch and run at EL2.
// If we are running at EL2 stay in EL2
// If we are starting at EL1 stay in EL1.
// If started at EL3 Sec is run and switches to EL2 before jumping to PEI.
// If started at EL1 or EL2 Sec jumps directly to PEI without making any
// changes.
// Which EL are we running at? Every EL needs some level of setup...
// We should not run this code in EL3
EL1_OR_EL2(x0)
1:bl ASM_PFX(SetupExceptionLevel1)
b ASM_PFX(MainEntryPoint)
2:bl ASM_PFX(SetupExceptionLevel2)
b ASM_PFX(MainEntryPoint)
ASM_PFX(MainEntryPoint):
// Identify CPU ID
bl ASM_PFX(ArmReadMpidr)
// Keep a copy of the MpId register value
mov x5, x0
// Is it the Primary Core ?
bl ASM_PFX(ArmPlatformIsPrimaryCore)
// Get the top of the primary stacks (and the base of the secondary stacks)
LoadConstantToReg (FixedPcdGet32(PcdCPUCoresStackBase), x1)
LoadConstantToReg (FixedPcdGet32(PcdCPUCorePrimaryStackSize), x2)
add x1, x1, x2
// x0 is equal to 1 if I am the primary core
cmp x0, #1
b.eq _SetupPrimaryCoreStack
_SetupSecondaryCoreStack:
// x1 contains the base of the secondary stacks
// Get the Core Position
mov x6, x1 // Save base of the secondary stacks
mov x0, x5
bl ASM_PFX(ArmPlatformGetCorePosition)
// The stack starts at the top of the stack region. Add '1' to the Core Position to get the top of the stack
add x0, x0, #1
// StackOffset = CorePos * StackSize
LoadConstantToReg (FixedPcdGet32(PcdCPUCoreSecondaryStackSize), x2)
mul x0, x0, x2
// SP = StackBase + StackOffset
add sp, x6, x0
_PrepareArguments:
// The PEI Core Entry Point has been computed by GenFV and stored in the second entry of the Reset Vector
LoadConstantToReg (FixedPcdGet64(PcdFvBaseAddress), x2)
add x2, x2, #8
ldr x1, [x2]
// Move sec startup address into a data register
// Ensure we're jumping to FV version of the code (not boot remapped alias)
ldr x3, StartupAddr
// Jump to PrePeiCore C code
// x0 = mp_id
// x1 = pei_core_address
mov x0, x5
blr x3
_SetupPrimaryCoreStack:
// x1 contains the top of the primary stack
LoadConstantToReg (FixedPcdGet32(PcdPeiGlobalVariableSize), x2)
// The reserved space for global variable must be 16-bytes aligned for pushing
// 128-bit variable on the stack
SetPrimaryStack (x1, x2, x3, x4)
b _PrepareArguments