audk/ArmPlatformPkg/PrePi/ModuleEntryPoint.S

149 lines
4.7 KiB
ArmAsm
Executable File

//
// Copyright (c) 2011-2012, 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
GCC_ASM_IMPORT(CEntryPoint)
GCC_ASM_IMPORT(ArmReadMpidr)
GCC_ASM_IMPORT(ArmPlatformStackSet)
GCC_ASM_EXPORT(_ModuleEntryPoint)
StartupAddr: .word CEntryPoint
ASM_PFX(_ModuleEntryPoint):
// Get ID of this CPU in Multicore system
bl ASM_PFX(ArmReadMpidr)
LoadConstantToReg (FixedPcdGet32(PcdArmPrimaryCoreMask), r1)
and r6, r0, r1
_SetSVCMode:
// Enter SVC mode, Disable FIQ and IRQ
//TODO: remove hardcoded values
mov r1, #0x13|0x80|0x40
msr CPSR_c, r1
// Check if we can install the stack 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)
sub r2, r2, #1
add r1, r1, r2 // r1 = SystemMemoryTop = PcdSystemMemoryBase + PcdSystemMemorySize
// Calculate Top of the Firmware Device
LoadConstantToReg (FixedPcdGet32(PcdFdBaseAddress), r2)
LoadConstantToReg (FixedPcdGet32(PcdFdSize), r3)
sub r3, r3, #1
add r3, r3, r2 // r3 = FdTop = PcdFdBaseAddress + PcdFdSize
// 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 r0, r1, r3 // r0 = SystemMemoryTop - FdTop
bmi _SetupStack // Jump if negative (FdTop > SystemMemoryTop). Case when the PrePi is in XIP memory outside of the DRAM
cmp r0, r4
bge _SetupStack
// Case the top of stacks is the FdBaseAddress
mov r1, r2
_SetupStack:
// r1 contains the top of the stack (and the UEFI Memory)
// Because the 'push' instruction is equivalent to 'stmdb' (decrement before), we need to increment
// one to the top of the stack. We check if incrementing one does not overflow (case of DRAM at the
// top of the memory space)
adds r7, r1, #1
bcs _SetupOverflowStack
_SetupAlignedStack:
mov r1, r7
b _GetBaseUefiMemory
_SetupOverflowStack:
// Case memory at the top of the address space. Ensure the top of the stack is EFI_PAGE_SIZE
// aligned (4KB)
LoadConstantToReg (EFI_PAGE_MASK, r7)
and r7, r7, r1
sub r1, r1, r7
_GetBaseUefiMemory:
// Calculate the Base of the UEFI Memory
sub r7, r1, r4
_GetStackBase:
// r1 = The top of the Mpcore Stacks
// Stack for the primary core = PrimaryCoreStack
LoadConstantToReg (FixedPcdGet32(PcdCPUCorePrimaryStackSize), r2)
sub r8, r1, r2
// Stack for the secondary core = Number of Cores - 1
LoadConstantToReg (FixedPcdGet32(PcdCoreCount), r0)
sub r0, r0, #1
LoadConstantToReg (FixedPcdGet32(PcdCPUCoreSecondaryStackSize), r1)
mul r1, r1, r0
sub r8, r8, r1
// r8 = The base of the MpCore Stacks (primary stack & secondary stacks)
mov r0, r8
mov r1, r6
//ArmPlatformStackSet(StackBase, MpId, PrimaryStackSize, SecondaryStackSize)
LoadConstantToReg (FixedPcdGet32(PcdCPUCorePrimaryStackSize), r2)
LoadConstantToReg (FixedPcdGet32(PcdCPUCoreSecondaryStackSize), r3)
bl ASM_PFX(ArmPlatformStackSet)
// Is it the Primary Core ?
LoadConstantToReg (FixedPcdGet32(PcdArmPrimaryCore), r4)
cmp r6, r4
bne _PrepareArguments
_ReserveGlobalVariable:
LoadConstantToReg (FixedPcdGet32(PcdPeiGlobalVariableSize), r0)
// InitializePrimaryStack($GlobalVariableSize, $Tmp1)
InitializePrimaryStack(r0, r1)
_PrepareArguments:
mov r0, r6
mov r1, r7
mov r2, r8
mov r3, sp
// Move sec startup address into a data register
// Ensure we're jumping to FV version of the code (not boot remapped alias)
ldr r4, StartupAddr
// Jump to PrePiCore C code
// r0 = MpId
// r1 = UefiMemoryBase
// r2 = StacksBase
// r3 = GlobalVariableBase
blx r4
_NeverReturn:
b _NeverReturn