audk/ArmPlatformPkg/PrePi/AArch64/ModuleEntryPoint.S

117 lines
3.5 KiB
ArmAsm

//
// Copyright (c) 2011-2015, ARM Limited. All rights reserved.
//
// SPDX-License-Identifier: BSD-2-Clause-Patent
//
//
#include <AsmMacroIoLibV8.h>
ASM_FUNC(_ModuleEntryPoint)
// Do early platform specific actions
bl ASM_PFX(ArmPlatformPeiBootAction)
// Get ID of this CPU in Multicore system
bl ASM_PFX(ArmReadMpidr)
// Keep a copy of the MpId register value
mov x10, x0
_SetSVCMode:
// 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)
_SystemMemoryEndInit:
ldr x1, mSystemMemoryEnd
_SetupStackPosition:
// r1 = SystemMemoryTop
// Calculate Top of the Firmware Device
MOV64 (x2, FixedPcdGet64(PcdFdBaseAddress))
MOV32 (x3, FixedPcdGet32(PcdFdSize) - 1)
sub x3, x3, #1
add x3, x3, x2 // x3 = FdTop = PcdFdBaseAddress + PcdFdSize
// UEFI Memory Size (stacks are allocated in this region)
MOV32 (x4, FixedPcdGet32(PcdSystemMemoryUefiRegionSize))
//
// 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 x0, x1, x3 // x0 = SystemMemoryTop - FdTop
b.mi _SetupStack // Jump if negative (FdTop > SystemMemoryTop). Case when the PrePi is in XIP memory outside of the DRAM
cmp x0, x4
b.ge _SetupStack
// Case the top of stacks is the FdBaseAddress
mov x1, x2
_SetupStack:
// x1 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 x11, x1, #1
b.cs _SetupOverflowStack
_SetupAlignedStack:
mov x1, x11
b _GetBaseUefiMemory
_SetupOverflowStack:
// Case memory at the top of the address space. Ensure the top of the stack is EFI_PAGE_SIZE
// aligned (4KB)
and x1, x1, ~EFI_PAGE_MASK
_GetBaseUefiMemory:
// Calculate the Base of the UEFI Memory
sub x11, x1, x4
_GetStackBase:
// r1 = The top of the Mpcore Stacks
// Stack for the primary core = PrimaryCoreStack
MOV32 (x2, FixedPcdGet32(PcdCPUCorePrimaryStackSize))
sub x12, x1, x2
// Stack for the secondary core = Number of Cores - 1
MOV32 (x1, (FixedPcdGet32(PcdCoreCount) - 1) * FixedPcdGet32(PcdCPUCoreSecondaryStackSize))
sub x12, x12, x1
// x12 = The base of the MpCore Stacks (primary stack & secondary stacks)
mov x0, x12
mov x1, x10
//ArmPlatformStackSet(StackBase, MpId, PrimaryStackSize, SecondaryStackSize)
MOV32 (x2, FixedPcdGet32(PcdCPUCorePrimaryStackSize))
MOV32 (x3, FixedPcdGet32(PcdCPUCoreSecondaryStackSize))
bl ASM_PFX(ArmPlatformStackSet)
// Is it the Primary Core ?
mov x0, x10
bl ASM_PFX(ArmPlatformIsPrimaryCore)
cmp x0, #1
bne _PrepareArguments
_PrepareArguments:
mov x0, x10
mov x1, x11
mov x2, x12
// Move sec startup address into a data register
// Ensure we're jumping to FV version of the code (not boot remapped alias)
ldr x4, =ASM_PFX(CEntryPoint)
// Set the frame pointer to NULL so any backtraces terminate here
mov x29, xzr
// Jump to PrePiCore C code
// x0 = MpId
// x1 = UefiMemoryBase
// x2 = StacksBase
blr x4
_NeverReturn:
b _NeverReturn