audk/ArmPlatformPkg/PrePi/Arm/ModuleEntryPoint.S

125 lines
3.7 KiB
ArmAsm

//
// Copyright (c) 2011 - 2020, Arm Limited. All rights reserved.<BR>
//
// SPDX-License-Identifier: BSD-2-Clause-Patent
//
//
#include <AsmMacroIoLib.h>
#include <Chipset/ArmV7.h>
ASM_FUNC(_ModuleEntryPoint)
// Do early platform specific actions
bl ASM_PFX(ArmPlatformPeiBootAction)
// Get ID of this CPU in multi-core system
bl ASM_PFX(ArmReadMpidr)
// Keep a copy of the MpId register value
mov r8, r0
_SetSVCMode:
// Enter SVC mode, Disable FIQ and IRQ
mov r1, #(CPSR_MODE_SVC | CPSR_IRQ | CPSR_FIQ)
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)
_SystemMemoryEndInit:
ADRL (r1, mSystemMemoryEnd)
ldrd r2, r3, [r1]
teq r3, #0
moveq r1, r2
mvnne r1, #0
_SetupStackPosition:
// r1 = SystemMemoryTop
// Calculate Top of the Firmware Device
MOV32 (r2, FixedPcdGet32(PcdFdBaseAddress))
MOV32 (r3, FixedPcdGet32(PcdFdSize) - 1)
add r3, r3, r2 // r3 = FdTop = PcdFdBaseAddress + PcdFdSize
// UEFI Memory Size (stacks are allocated in this region)
MOV32 (r4, 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 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 r9, r1, #1
bcs _SetupOverflowStack
_SetupAlignedStack:
mov r1, r9
b _GetBaseUefiMemory
_SetupOverflowStack:
// Case memory at the top of the address space. Ensure the top of the stack is EFI_PAGE_SIZE
// aligned (4KB)
MOV32 (r9, ~EFI_PAGE_MASK & 0xFFFFFFFF)
and r1, r1, r9
_GetBaseUefiMemory:
// Calculate the Base of the UEFI Memory
sub r9, r1, r4
_GetStackBase:
// r1 = The top of the Mpcore Stacks
// Stack for the primary core = PrimaryCoreStack
MOV32 (r2, FixedPcdGet32(PcdCPUCorePrimaryStackSize))
sub r10, r1, r2
// Stack for the secondary core = Number of Cores - 1
MOV32 (r1, (FixedPcdGet32(PcdCoreCount) - 1) * FixedPcdGet32(PcdCPUCoreSecondaryStackSize))
sub r10, r10, r1
// r10 = The base of the MpCore Stacks (primary stack & secondary stacks)
mov r0, r10
mov r1, r8
//ArmPlatformStackSet(StackBase, MpId, PrimaryStackSize, SecondaryStackSize)
MOV32 (r2, FixedPcdGet32(PcdCPUCorePrimaryStackSize))
MOV32 (r3, FixedPcdGet32(PcdCPUCoreSecondaryStackSize))
bl ASM_PFX(ArmPlatformStackSet)
// Is it the Primary Core ?
mov r0, r8
bl ASM_PFX(ArmPlatformIsPrimaryCore)
cmp r0, #1
bne _PrepareArguments
_PrepareArguments:
mov r0, r8
mov r1, r9
mov r2, r10
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, =ASM_PFX(CEntryPoint)
// Jump to PrePiCore C code
// r0 = MpId
// r1 = UefiMemoryBase
// r2 = StacksBase
blx r4
_NeverReturn:
b _NeverReturn