audk/ArmVirtPkg/PrePi/Arm/ModuleEntryPoint.S

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//
// Copyright (c) 2011-2013, ARM Limited. All rights reserved.
// Copyright (c) 2015, Linaro 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(ArmPlatformIsPrimaryCore)
GCC_ASM_IMPORT(ArmReadMpidr)
GCC_ASM_IMPORT(ArmPlatformPeiBootAction)
GCC_ASM_IMPORT(ArmPlatformStackSet)
GCC_ASM_EXPORT(_ModuleEntryPoint)
ASM_GLOBAL ASM_PFX(mSystemMemoryEnd)
StartupAddr: .long ASM_PFX(CEntryPoint)
ASM_PFX(mSystemMemoryEnd): .quad 0
__relocs:
.long __reloc_base - __relocs
.long __reloc_start - __relocs
.long __reloc_end - __relocs
ASM_PFX(_ModuleEntryPoint):
//
// We are built as a ET_DYN PIE executable, so we need to process all
// relative relocations if we are executing from a different offset than we
// were linked at. This is only possible if we are running from RAM.
//
adr r12, __relocs
ldrd r4, r5, [r12]
ldr r6, [r12, #8]
add r4, r4, r12
add r5, r5, r12
add r6, r6, r12
.Lreloc_loop:
cmp r5, r6
bhs .Lreloc_done
//
// AArch32 uses the ELF32 REL format, which means each entry in the
// relocation table consists of
//
// UINT32 offset : the relative offset of the value that needs to
// be relocated
// UINT32 info : relocation type and symbol index (the latter is
// not used for R_ARM_RELATIVE relocations)
//
ldrd r8, r9, [r5], #8 // read offset into r8 and info into r9
cmp r9, #23 // check info == R_ARM_RELATIVE?
bne .Lreloc_loop // not a relative relocation? then skip
ldr r9, [r8, r4] // read addend into r9
add r9, r9, r1 // add image base to addend to get relocated value
str r9, [r8, r4] // write relocated value at offset
b .Lreloc_loop
.Lreloc_done:
// 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 r10, r0
// 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
ldr r12, =PcdGet64 (PcdSystemMemoryBase)
ldr r1, [r12]
ldr r12, =PcdGet64 (PcdSystemMemorySize)
ldrd r2, r3, [r12]
// calculate the top of memory, and record it in mSystemMemoryEnd
adds r2, r2, r1
sub r2, r2, #1
addcs r3, r3, #1
adr r12, mSystemMemoryEnd
strd r2, r3, [r12]
// truncate the memory used by UEFI to 4 GB range
teq r3, #0
movne r1, #-1
moveq r1, r2
// Calculate Top of the Firmware Device
ldr r12, =PcdGet64 (PcdFdBaseAddress)
ldr r2, [r12]
ldr r3, =FixedPcdGet32 (PcdFdSize)
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 r11, r1, #1
bcs _SetupOverflowStack
_SetupAlignedStack:
mov r1, r11
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, r11)
and r11, r11, r1
sub r1, r1, r11
_GetBaseUefiMemory:
// Calculate the Base of the UEFI Memory
sub r11, r1, r4
_GetStackBase:
// r1 = The top of the Mpcore Stacks
// Stack for the primary core = PrimaryCoreStack
LoadConstantToReg (FixedPcdGet32(PcdCPUCorePrimaryStackSize), r2)
sub r12, 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 r12, r12, r1
// r12 = The base of the MpCore Stacks (primary stack & secondary stacks)
mov r0, r12
mov r1, r10
//ArmPlatformStackSet(StackBase, MpId, PrimaryStackSize, SecondaryStackSize)
LoadConstantToReg (FixedPcdGet32(PcdCPUCorePrimaryStackSize), r2)
LoadConstantToReg (FixedPcdGet32(PcdCPUCoreSecondaryStackSize), r3)
bl ASM_PFX(ArmPlatformStackSet)
// Is it the Primary Core ?
mov r0, r10
bl ASM_PFX(ArmPlatformIsPrimaryCore)
cmp r0, #1
bne _PrepareArguments
_PrepareArguments:
mov r0, r10
mov r1, r11
mov r2, r12
// 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
blx r4
_NeverReturn:
b _NeverReturn