mirror of https://github.com/acidanthera/audk.git
209 lines
6.7 KiB
ArmAsm
209 lines
6.7 KiB
ArmAsm
//
|
|
// Copyright (c) 2011-2013, ARM Limited. All rights reserved.
|
|
// Copyright (c) 2015-2016, 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 <AsmMacroIoLibV8.h>
|
|
|
|
ASM_FUNC(_ModuleEntryPoint)
|
|
//
|
|
// We are built as a ET_DYN PIE executable, so we need to process all
|
|
// relative relocations regardless of whether or not we are executing from
|
|
// the same offset we were linked at. This is only possible if we are
|
|
// running from RAM.
|
|
//
|
|
adr x8, __reloc_base
|
|
adr x9, __reloc_start
|
|
adr x10, __reloc_end
|
|
|
|
.Lreloc_loop:
|
|
cmp x9, x10
|
|
bhs .Lreloc_done
|
|
|
|
//
|
|
// AArch64 uses the ELF64 RELA format, which means each entry in the
|
|
// relocation table consists of
|
|
//
|
|
// UINT64 offset : the relative offset of the value that needs to
|
|
// be relocated
|
|
// UINT64 info : relocation type and symbol index (the latter is
|
|
// not used for R_AARCH64_RELATIVE relocations)
|
|
// UINT64 addend : value to be added to the value being relocated
|
|
//
|
|
ldp x11, x12, [x9], #24 // read offset into x11 and info into x12
|
|
cmp x12, #0x403 // check info == R_AARCH64_RELATIVE?
|
|
bne .Lreloc_loop // not a relative relocation? then skip
|
|
|
|
ldr x12, [x9, #-8] // read addend into x12
|
|
add x12, x12, x8 // add reloc base to addend to get relocated value
|
|
str x12, [x11, x8] // write relocated value at offset
|
|
b .Lreloc_loop
|
|
.Lreloc_done:
|
|
|
|
bl ASM_PFX(DiscoverDramFromDt)
|
|
|
|
// Get ID of this CPU in Multicore system
|
|
bl ASM_PFX(ArmReadMpidr)
|
|
// Keep a copy of the MpId register value
|
|
mov x20, x0
|
|
|
|
// 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 x1, PcdGet64 (PcdSystemMemoryBase)
|
|
ldr x2, PcdGet64 (PcdSystemMemorySize)
|
|
sub x2, x2, #1
|
|
add x1, x1, x2 // x1 = SystemMemoryTop = PcdSystemMemoryBase + PcdSystemMemorySize
|
|
|
|
// Calculate Top of the Firmware Device
|
|
ldr x2, PcdGet64 (PcdFdBaseAddress)
|
|
MOV32 (w3, FixedPcdGet32 (PcdFdSize) - 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 x21, x1, #1
|
|
b.cs _SetupOverflowStack
|
|
|
|
_SetupAlignedStack:
|
|
mov x1, x21
|
|
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 x21, x1, x4
|
|
|
|
_GetStackBase:
|
|
// r1 = The top of the Mpcore Stacks
|
|
mov sp, x1
|
|
|
|
// Stack for the primary core = PrimaryCoreStack
|
|
MOV32 (x2, FixedPcdGet32(PcdCPUCorePrimaryStackSize))
|
|
sub x22, x1, x2
|
|
|
|
mov x0, x20
|
|
mov x1, x21
|
|
mov x2, x22
|
|
|
|
// 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
|
|
bl ASM_PFX(CEntryPoint)
|
|
|
|
_NeverReturn:
|
|
b _NeverReturn
|
|
|
|
// VOID
|
|
// DiscoverDramFromDt (
|
|
// VOID *DeviceTreeBaseAddress, // passed by loader in x0
|
|
// VOID *ImageBase // passed by FDF trampoline in x1
|
|
// );
|
|
ASM_PFX(DiscoverDramFromDt):
|
|
//
|
|
// If we are booting from RAM using the Linux kernel boot protocol, x0 will
|
|
// point to the DTB image in memory. Otherwise, use the default value defined
|
|
// by the platform.
|
|
//
|
|
cbnz x0, 0f
|
|
ldr x0, PcdGet64 (PcdDeviceTreeInitialBaseAddress)
|
|
|
|
0:mov x29, x30 // preserve LR
|
|
mov x28, x0 // preserve DTB pointer
|
|
mov x27, x1 // preserve base of image pointer
|
|
|
|
//
|
|
// The base of the runtime image has been preserved in x1. Check whether
|
|
// the expected magic number can be found in the header.
|
|
//
|
|
ldr w8, .LArm64LinuxMagic
|
|
ldr w9, [x1, #0x38]
|
|
cmp w8, w9
|
|
bne .Lout
|
|
|
|
//
|
|
//
|
|
// OK, so far so good. We have confirmed that we likely have a DTB and are
|
|
// booting via the arm64 Linux boot protocol. Update the base-of-image PCD
|
|
// to the actual relocated value, and add the shift of PcdFdBaseAddress to
|
|
// PcdFvBaseAddress as well
|
|
//
|
|
adr x8, PcdGet64 (PcdFdBaseAddress)
|
|
adr x9, PcdGet64 (PcdFvBaseAddress)
|
|
ldr x6, [x8]
|
|
ldr x7, [x9]
|
|
sub x7, x7, x6
|
|
add x7, x7, x1
|
|
str x1, [x8]
|
|
str x7, [x9]
|
|
|
|
//
|
|
// Discover the memory size and offset from the DTB, and record in the
|
|
// respective PCDs. This will also return false if a corrupt DTB is
|
|
// encountered. Since we are calling a C function, use the window at the
|
|
// beginning of the FD image as a temp stack.
|
|
//
|
|
adr x1, PcdGet64 (PcdSystemMemoryBase)
|
|
adr x2, PcdGet64 (PcdSystemMemorySize)
|
|
mov sp, x7
|
|
bl FindMemnode
|
|
cbz x0, .Lout
|
|
|
|
//
|
|
// Copy the DTB to the slack space right after the 64 byte arm64/Linux style
|
|
// image header at the base of this image (defined in the FDF), and record the
|
|
// pointer in PcdDeviceTreeInitialBaseAddress.
|
|
//
|
|
adr x8, PcdGet64 (PcdDeviceTreeInitialBaseAddress)
|
|
add x27, x27, #0x40
|
|
str x27, [x8]
|
|
|
|
mov x0, x27
|
|
mov x1, x28
|
|
bl CopyFdt
|
|
|
|
.Lout:
|
|
ret x29
|
|
|
|
.LArm64LinuxMagic:
|
|
.byte 0x41, 0x52, 0x4d, 0x64
|