1// 2// Copyright (c) 2011-2013, ARM Limited. All rights reserved. 3// Copyright (c) 2015-2016, Linaro Limited. All rights reserved. 4// 5// This program and the accompanying materials 6// are licensed and made available under the terms and conditions of the BSD License 7// which accompanies this distribution. The full text of the license may be found at 8// http://opensource.org/licenses/bsd-license.php 9// 10// THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, 11// WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. 12// 13// 14 15#include <AsmMacroIoLibV8.h> 16 17ASM_FUNC(_ModuleEntryPoint) 18 // 19 // We are built as a ET_DYN PIE executable, so we need to process all 20 // relative relocations regardless of whether or not we are executing from 21 // the same offset we were linked at. This is only possible if we are 22 // running from RAM. 23 // 24 adr x8, __reloc_base 25 adr x9, __reloc_start 26 adr x10, __reloc_end 27 28.Lreloc_loop: 29 cmp x9, x10 30 bhs .Lreloc_done 31 32 // 33 // AArch64 uses the ELF64 RELA format, which means each entry in the 34 // relocation table consists of 35 // 36 // UINT64 offset : the relative offset of the value that needs to 37 // be relocated 38 // UINT64 info : relocation type and symbol index (the latter is 39 // not used for R_AARCH64_RELATIVE relocations) 40 // UINT64 addend : value to be added to the value being relocated 41 // 42 ldp x11, x12, [x9], #24 // read offset into x11 and info into x12 43 cmp x12, #0x403 // check info == R_AARCH64_RELATIVE? 44 bne .Lreloc_loop // not a relative relocation? then skip 45 46 ldr x12, [x9, #-8] // read addend into x12 47 add x12, x12, x8 // add reloc base to addend to get relocated value 48 str x12, [x11, x8] // write relocated value at offset 49 b .Lreloc_loop 50.Lreloc_done: 51 52 // Do early platform specific actions 53 bl ASM_PFX(ArmPlatformPeiBootAction) 54 55 // Get ID of this CPU in Multicore system 56 bl ASM_PFX(ArmReadMpidr) 57 // Keep a copy of the MpId register value 58 mov x20, x0 59 60// Check if we can install the stack at the top of the System Memory or if we need 61// to install the stacks at the bottom of the Firmware Device (case the FD is located 62// at the top of the DRAM) 63_SetupStackPosition: 64 // Compute Top of System Memory 65 ldr x1, PcdGet64 (PcdSystemMemoryBase) 66 ldr x2, PcdGet64 (PcdSystemMemorySize) 67 sub x2, x2, #1 68 add x1, x1, x2 // x1 = SystemMemoryTop = PcdSystemMemoryBase + PcdSystemMemorySize 69 70 // Calculate Top of the Firmware Device 71 ldr x2, PcdGet64 (PcdFdBaseAddress) 72 MOV32 (w3, FixedPcdGet32 (PcdFdSize) - 1) 73 add x3, x3, x2 // x3 = FdTop = PcdFdBaseAddress + PcdFdSize 74 75 // UEFI Memory Size (stacks are allocated in this region) 76 MOV32 (x4, FixedPcdGet32(PcdSystemMemoryUefiRegionSize)) 77 78 // 79 // Reserve the memory for the UEFI region (contain stacks on its top) 80 // 81 82 // Calculate how much space there is between the top of the Firmware and the Top of the System Memory 83 subs x0, x1, x3 // x0 = SystemMemoryTop - FdTop 84 b.mi _SetupStack // Jump if negative (FdTop > SystemMemoryTop). Case when the PrePi is in XIP memory outside of the DRAM 85 cmp x0, x4 86 b.ge _SetupStack 87 88 // Case the top of stacks is the FdBaseAddress 89 mov x1, x2 90 91_SetupStack: 92 // x1 contains the top of the stack (and the UEFI Memory) 93 94 // Because the 'push' instruction is equivalent to 'stmdb' (decrement before), we need to increment 95 // one to the top of the stack. We check if incrementing one does not overflow (case of DRAM at the 96 // top of the memory space) 97 adds x21, x1, #1 98 b.cs _SetupOverflowStack 99 100_SetupAlignedStack: 101 mov x1, x21 102 b _GetBaseUefiMemory 103 104_SetupOverflowStack: 105 // Case memory at the top of the address space. Ensure the top of the stack is EFI_PAGE_SIZE 106 // aligned (4KB) 107 and x1, x1, ~EFI_PAGE_MASK 108 109_GetBaseUefiMemory: 110 // Calculate the Base of the UEFI Memory 111 sub x21, x1, x4 112 113_GetStackBase: 114 // r1 = The top of the Mpcore Stacks 115 // Stack for the primary core = PrimaryCoreStack 116 MOV32 (x2, FixedPcdGet32(PcdCPUCorePrimaryStackSize)) 117 sub x22, x1, x2 118 119 // Stack for the secondary core = Number of Cores - 1 120 MOV32 (x1, (FixedPcdGet32(PcdCoreCount) - 1) * FixedPcdGet32(PcdCPUCoreSecondaryStackSize)) 121 sub x22, x22, x1 122 123 // x22 = The base of the MpCore Stacks (primary stack & secondary stacks) 124 mov x0, x22 125 mov x1, x20 126 //ArmPlatformStackSet(StackBase, MpId, PrimaryStackSize, SecondaryStackSize) 127 MOV32 (x2, FixedPcdGet32(PcdCPUCorePrimaryStackSize)) 128 MOV32 (x3, FixedPcdGet32(PcdCPUCoreSecondaryStackSize)) 129 bl ASM_PFX(ArmPlatformStackSet) 130 131 // Is it the Primary Core ? 132 mov x0, x10 133 bl ASM_PFX(ArmPlatformIsPrimaryCore) 134 cmp x0, #1 135 bne _PrepareArguments 136 137_PrepareArguments: 138 mov x0, x20 139 mov x1, x21 140 mov x2, x22 141 142 // Jump to PrePiCore C code 143 // x0 = MpId 144 // x1 = UefiMemoryBase 145 // x2 = StacksBase 146 bl ASM_PFX(CEntryPoint) 147 148_NeverReturn: 149 b _NeverReturn 150