850 lines
23 KiB
ArmAsm
850 lines
23 KiB
ArmAsm
/*
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* Low-level CPU initialisation
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* Based on arch/arm/kernel/head.S
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*
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* Copyright (C) 1994-2002 Russell King
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* Copyright (C) 2003-2012 ARM Ltd.
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* Authors: Catalin Marinas <catalin.marinas@arm.com>
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* Will Deacon <will.deacon@arm.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <linux/linkage.h>
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#include <linux/init.h>
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#include <linux/irqchip/arm-gic-v3.h>
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#include <asm/assembler.h>
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#include <asm/boot.h>
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#include <asm/ptrace.h>
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#include <asm/asm-offsets.h>
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#include <asm/cache.h>
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#include <asm/cputype.h>
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#include <asm/elf.h>
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#include <asm/kernel-pgtable.h>
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#include <asm/kvm_arm.h>
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#include <asm/memory.h>
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#include <asm/pgtable-hwdef.h>
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#include <asm/pgtable.h>
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#include <asm/page.h>
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#include <asm/smp.h>
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#include <asm/sysreg.h>
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#include <asm/thread_info.h>
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#include <asm/virt.h>
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#define __PHYS_OFFSET (KERNEL_START - TEXT_OFFSET)
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#if (TEXT_OFFSET & 0xfff) != 0
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#error TEXT_OFFSET must be at least 4KB aligned
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#elif (PAGE_OFFSET & 0x1fffff) != 0
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#error PAGE_OFFSET must be at least 2MB aligned
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#elif TEXT_OFFSET > 0x1fffff
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#error TEXT_OFFSET must be less than 2MB
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#endif
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/*
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* Kernel startup entry point.
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* ---------------------------
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*
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* The requirements are:
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* MMU = off, D-cache = off, I-cache = on or off,
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* x0 = physical address to the FDT blob.
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*
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* This code is mostly position independent so you call this at
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* __pa(PAGE_OFFSET + TEXT_OFFSET).
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*
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* Note that the callee-saved registers are used for storing variables
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* that are useful before the MMU is enabled. The allocations are described
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* in the entry routines.
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*/
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__HEAD
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_head:
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/*
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* DO NOT MODIFY. Image header expected by Linux boot-loaders.
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*/
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#ifdef CONFIG_EFI
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/*
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* This add instruction has no meaningful effect except that
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* its opcode forms the magic "MZ" signature required by UEFI.
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*/
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add x13, x18, #0x16
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b stext
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#else
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b stext // branch to kernel start, magic
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.long 0 // reserved
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#endif
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le64sym _kernel_offset_le // Image load offset from start of RAM, little-endian
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le64sym _kernel_size_le // Effective size of kernel image, little-endian
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le64sym _kernel_flags_le // Informative flags, little-endian
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.quad 0 // reserved
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.quad 0 // reserved
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.quad 0 // reserved
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.byte 0x41 // Magic number, "ARM\x64"
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.byte 0x52
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.byte 0x4d
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.byte 0x64
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#ifdef CONFIG_EFI
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.long pe_header - _head // Offset to the PE header.
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#else
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.word 0 // reserved
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#endif
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#ifdef CONFIG_EFI
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.align 3
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pe_header:
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.ascii "PE"
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.short 0
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coff_header:
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.short 0xaa64 // AArch64
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.short 2 // nr_sections
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.long 0 // TimeDateStamp
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.long 0 // PointerToSymbolTable
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.long 1 // NumberOfSymbols
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.short section_table - optional_header // SizeOfOptionalHeader
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.short 0x206 // Characteristics.
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// IMAGE_FILE_DEBUG_STRIPPED |
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// IMAGE_FILE_EXECUTABLE_IMAGE |
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// IMAGE_FILE_LINE_NUMS_STRIPPED
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optional_header:
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.short 0x20b // PE32+ format
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.byte 0x02 // MajorLinkerVersion
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.byte 0x14 // MinorLinkerVersion
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.long _end - efi_header_end // SizeOfCode
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.long 0 // SizeOfInitializedData
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.long 0 // SizeOfUninitializedData
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.long __efistub_entry - _head // AddressOfEntryPoint
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.long efi_header_end - _head // BaseOfCode
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extra_header_fields:
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.quad 0 // ImageBase
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.long 0x1000 // SectionAlignment
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.long PECOFF_FILE_ALIGNMENT // FileAlignment
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.short 0 // MajorOperatingSystemVersion
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.short 0 // MinorOperatingSystemVersion
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.short 0 // MajorImageVersion
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.short 0 // MinorImageVersion
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.short 0 // MajorSubsystemVersion
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.short 0 // MinorSubsystemVersion
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.long 0 // Win32VersionValue
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.long _end - _head // SizeOfImage
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// Everything before the kernel image is considered part of the header
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.long efi_header_end - _head // SizeOfHeaders
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.long 0 // CheckSum
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.short 0xa // Subsystem (EFI application)
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.short 0 // DllCharacteristics
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.quad 0 // SizeOfStackReserve
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.quad 0 // SizeOfStackCommit
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.quad 0 // SizeOfHeapReserve
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.quad 0 // SizeOfHeapCommit
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.long 0 // LoaderFlags
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.long 0x6 // NumberOfRvaAndSizes
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.quad 0 // ExportTable
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.quad 0 // ImportTable
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.quad 0 // ResourceTable
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.quad 0 // ExceptionTable
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.quad 0 // CertificationTable
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.quad 0 // BaseRelocationTable
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// Section table
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section_table:
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/*
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* The EFI application loader requires a relocation section
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* because EFI applications must be relocatable. This is a
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* dummy section as far as we are concerned.
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*/
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.ascii ".reloc"
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.byte 0
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.byte 0 // end of 0 padding of section name
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.long 0
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.long 0
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.long 0 // SizeOfRawData
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.long 0 // PointerToRawData
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.long 0 // PointerToRelocations
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.long 0 // PointerToLineNumbers
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.short 0 // NumberOfRelocations
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.short 0 // NumberOfLineNumbers
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.long 0x42100040 // Characteristics (section flags)
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.ascii ".text"
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.byte 0
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.byte 0
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.byte 0 // end of 0 padding of section name
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.long _end - efi_header_end // VirtualSize
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.long efi_header_end - _head // VirtualAddress
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.long _edata - efi_header_end // SizeOfRawData
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.long efi_header_end - _head // PointerToRawData
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.long 0 // PointerToRelocations (0 for executables)
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.long 0 // PointerToLineNumbers (0 for executables)
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.short 0 // NumberOfRelocations (0 for executables)
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.short 0 // NumberOfLineNumbers (0 for executables)
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.long 0xe0500020 // Characteristics (section flags)
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/*
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* EFI will load .text onwards at the 4k section alignment
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* described in the PE/COFF header. To ensure that instruction
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* sequences using an adrp and a :lo12: immediate will function
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* correctly at this alignment, we must ensure that .text is
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* placed at a 4k boundary in the Image to begin with.
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*/
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.align 12
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efi_header_end:
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#endif
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__INIT
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/*
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* The following callee saved general purpose registers are used on the
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* primary lowlevel boot path:
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*
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* Register Scope Purpose
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* x21 stext() .. start_kernel() FDT pointer passed at boot in x0
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* x23 stext() .. start_kernel() physical misalignment/KASLR offset
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* x28 __create_page_tables() callee preserved temp register
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* x19/x20 __primary_switch() callee preserved temp registers
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*/
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ENTRY(stext)
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bl preserve_boot_args
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bl el2_setup // Drop to EL1, w0=cpu_boot_mode
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adrp x23, __PHYS_OFFSET
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and x23, x23, MIN_KIMG_ALIGN - 1 // KASLR offset, defaults to 0
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bl set_cpu_boot_mode_flag
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bl __create_page_tables
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/*
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* The following calls CPU setup code, see arch/arm64/mm/proc.S for
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* details.
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* On return, the CPU will be ready for the MMU to be turned on and
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* the TCR will have been set.
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*/
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bl __cpu_setup // initialise processor
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b __primary_switch
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ENDPROC(stext)
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/*
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* Preserve the arguments passed by the bootloader in x0 .. x3
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*/
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preserve_boot_args:
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mov x21, x0 // x21=FDT
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adr_l x0, boot_args // record the contents of
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stp x21, x1, [x0] // x0 .. x3 at kernel entry
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stp x2, x3, [x0, #16]
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dmb sy // needed before dc ivac with
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// MMU off
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add x1, x0, #0x20 // 4 x 8 bytes
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b __inval_cache_range // tail call
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ENDPROC(preserve_boot_args)
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/*
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* Macro to create a table entry to the next page.
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*
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* tbl: page table address
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* virt: virtual address
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* shift: #imm page table shift
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* ptrs: #imm pointers per table page
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*
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* Preserves: virt
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* Corrupts: tmp1, tmp2
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* Returns: tbl -> next level table page address
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*/
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.macro create_table_entry, tbl, virt, shift, ptrs, tmp1, tmp2
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lsr \tmp1, \virt, #\shift
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and \tmp1, \tmp1, #\ptrs - 1 // table index
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add \tmp2, \tbl, #PAGE_SIZE
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orr \tmp2, \tmp2, #PMD_TYPE_TABLE // address of next table and entry type
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str \tmp2, [\tbl, \tmp1, lsl #3]
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add \tbl, \tbl, #PAGE_SIZE // next level table page
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.endm
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/*
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* Macro to populate the PGD (and possibily PUD) for the corresponding
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* block entry in the next level (tbl) for the given virtual address.
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*
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* Preserves: tbl, next, virt
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* Corrupts: tmp1, tmp2
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*/
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.macro create_pgd_entry, tbl, virt, tmp1, tmp2
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create_table_entry \tbl, \virt, PGDIR_SHIFT, PTRS_PER_PGD, \tmp1, \tmp2
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#if SWAPPER_PGTABLE_LEVELS > 3
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create_table_entry \tbl, \virt, PUD_SHIFT, PTRS_PER_PUD, \tmp1, \tmp2
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#endif
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#if SWAPPER_PGTABLE_LEVELS > 2
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create_table_entry \tbl, \virt, SWAPPER_TABLE_SHIFT, PTRS_PER_PTE, \tmp1, \tmp2
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#endif
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.endm
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/*
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* Macro to populate block entries in the page table for the start..end
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* virtual range (inclusive).
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*
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* Preserves: tbl, flags
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* Corrupts: phys, start, end, pstate
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*/
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.macro create_block_map, tbl, flags, phys, start, end
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lsr \phys, \phys, #SWAPPER_BLOCK_SHIFT
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lsr \start, \start, #SWAPPER_BLOCK_SHIFT
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and \start, \start, #PTRS_PER_PTE - 1 // table index
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orr \phys, \flags, \phys, lsl #SWAPPER_BLOCK_SHIFT // table entry
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lsr \end, \end, #SWAPPER_BLOCK_SHIFT
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and \end, \end, #PTRS_PER_PTE - 1 // table end index
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9999: str \phys, [\tbl, \start, lsl #3] // store the entry
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add \start, \start, #1 // next entry
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add \phys, \phys, #SWAPPER_BLOCK_SIZE // next block
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cmp \start, \end
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b.ls 9999b
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.endm
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/*
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* Setup the initial page tables. We only setup the barest amount which is
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* required to get the kernel running. The following sections are required:
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* - identity mapping to enable the MMU (low address, TTBR0)
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* - first few MB of the kernel linear mapping to jump to once the MMU has
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* been enabled
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*/
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__create_page_tables:
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mov x28, lr
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/*
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* Invalidate the idmap and swapper page tables to avoid potential
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* dirty cache lines being evicted.
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*/
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adrp x0, idmap_pg_dir
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adrp x1, swapper_pg_dir + SWAPPER_DIR_SIZE + RESERVED_TTBR0_SIZE
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bl __inval_cache_range
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/*
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* Clear the idmap and swapper page tables.
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*/
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adrp x0, idmap_pg_dir
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adrp x6, swapper_pg_dir + SWAPPER_DIR_SIZE + RESERVED_TTBR0_SIZE
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1: stp xzr, xzr, [x0], #16
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stp xzr, xzr, [x0], #16
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stp xzr, xzr, [x0], #16
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stp xzr, xzr, [x0], #16
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cmp x0, x6
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b.lo 1b
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mov x7, SWAPPER_MM_MMUFLAGS
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/*
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* Create the identity mapping.
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*/
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adrp x0, idmap_pg_dir
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adrp x3, __idmap_text_start // __pa(__idmap_text_start)
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#ifndef CONFIG_ARM64_VA_BITS_48
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#define EXTRA_SHIFT (PGDIR_SHIFT + PAGE_SHIFT - 3)
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#define EXTRA_PTRS (1 << (48 - EXTRA_SHIFT))
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/*
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* If VA_BITS < 48, it may be too small to allow for an ID mapping to be
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* created that covers system RAM if that is located sufficiently high
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* in the physical address space. So for the ID map, use an extended
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* virtual range in that case, by configuring an additional translation
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* level.
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* First, we have to verify our assumption that the current value of
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* VA_BITS was chosen such that all translation levels are fully
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* utilised, and that lowering T0SZ will always result in an additional
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* translation level to be configured.
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*/
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#if VA_BITS != EXTRA_SHIFT
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#error "Mismatch between VA_BITS and page size/number of translation levels"
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#endif
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/*
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* Calculate the maximum allowed value for TCR_EL1.T0SZ so that the
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* entire ID map region can be mapped. As T0SZ == (64 - #bits used),
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* this number conveniently equals the number of leading zeroes in
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* the physical address of __idmap_text_end.
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*/
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adrp x5, __idmap_text_end
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clz x5, x5
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cmp x5, TCR_T0SZ(VA_BITS) // default T0SZ small enough?
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b.ge 1f // .. then skip additional level
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adr_l x6, idmap_t0sz
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str x5, [x6]
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dmb sy
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dc ivac, x6 // Invalidate potentially stale cache line
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create_table_entry x0, x3, EXTRA_SHIFT, EXTRA_PTRS, x5, x6
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1:
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#endif
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create_pgd_entry x0, x3, x5, x6
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mov x5, x3 // __pa(__idmap_text_start)
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adr_l x6, __idmap_text_end // __pa(__idmap_text_end)
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create_block_map x0, x7, x3, x5, x6
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/*
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* Map the kernel image (starting with PHYS_OFFSET).
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*/
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adrp x0, swapper_pg_dir
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mov_q x5, KIMAGE_VADDR + TEXT_OFFSET // compile time __va(_text)
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add x5, x5, x23 // add KASLR displacement
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create_pgd_entry x0, x5, x3, x6
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adrp x6, _end // runtime __pa(_end)
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adrp x3, _text // runtime __pa(_text)
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sub x6, x6, x3 // _end - _text
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add x6, x6, x5 // runtime __va(_end)
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create_block_map x0, x7, x3, x5, x6
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/*
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* Since the page tables have been populated with non-cacheable
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* accesses (MMU disabled), invalidate the idmap and swapper page
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* tables again to remove any speculatively loaded cache lines.
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*/
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adrp x0, idmap_pg_dir
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adrp x1, swapper_pg_dir + SWAPPER_DIR_SIZE + RESERVED_TTBR0_SIZE
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dmb sy
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bl __inval_cache_range
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ret x28
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ENDPROC(__create_page_tables)
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.ltorg
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/*
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* The following fragment of code is executed with the MMU enabled.
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*
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* x0 = __PHYS_OFFSET
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*/
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__primary_switched:
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adrp x4, init_thread_union
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add sp, x4, #THREAD_SIZE
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adr_l x5, init_task
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msr sp_el0, x5 // Save thread_info
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adr_l x8, vectors // load VBAR_EL1 with virtual
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msr vbar_el1, x8 // vector table address
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isb
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stp xzr, x30, [sp, #-16]!
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mov x29, sp
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str_l x21, __fdt_pointer, x5 // Save FDT pointer
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ldr_l x4, kimage_vaddr // Save the offset between
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sub x4, x4, x0 // the kernel virtual and
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str_l x4, kimage_voffset, x5 // physical mappings
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// Clear BSS
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adr_l x0, __bss_start
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mov x1, xzr
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adr_l x2, __bss_stop
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sub x2, x2, x0
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bl __pi_memset
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dsb ishst // Make zero page visible to PTW
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#ifdef CONFIG_KASAN
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bl kasan_early_init
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#endif
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#ifdef CONFIG_RANDOMIZE_BASE
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tst x23, ~(MIN_KIMG_ALIGN - 1) // already running randomized?
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b.ne 0f
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mov x0, x21 // pass FDT address in x0
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mov x1, x23 // pass modulo offset in x1
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bl kaslr_early_init // parse FDT for KASLR options
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cbz x0, 0f // KASLR disabled? just proceed
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orr x23, x23, x0 // record KASLR offset
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ldp x29, x30, [sp], #16 // we must enable KASLR, return
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ret // to __primary_switch()
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0:
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#endif
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b start_kernel
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ENDPROC(__primary_switched)
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/*
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* end early head section, begin head code that is also used for
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* hotplug and needs to have the same protections as the text region
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*/
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.section ".idmap.text","ax"
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ENTRY(kimage_vaddr)
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.quad _text - TEXT_OFFSET
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/*
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* If we're fortunate enough to boot at EL2, ensure that the world is
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* sane before dropping to EL1.
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*
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* Returns either BOOT_CPU_MODE_EL1 or BOOT_CPU_MODE_EL2 in x20 if
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* booted in EL1 or EL2 respectively.
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*/
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ENTRY(el2_setup)
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mrs x0, CurrentEL
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cmp x0, #CurrentEL_EL2
|
|
b.ne 1f
|
|
mrs x0, sctlr_el2
|
|
CPU_BE( orr x0, x0, #(1 << 25) ) // Set the EE bit for EL2
|
|
CPU_LE( bic x0, x0, #(1 << 25) ) // Clear the EE bit for EL2
|
|
msr sctlr_el2, x0
|
|
b 2f
|
|
1: mrs x0, sctlr_el1
|
|
CPU_BE( orr x0, x0, #(3 << 24) ) // Set the EE and E0E bits for EL1
|
|
CPU_LE( bic x0, x0, #(3 << 24) ) // Clear the EE and E0E bits for EL1
|
|
msr sctlr_el1, x0
|
|
mov w0, #BOOT_CPU_MODE_EL1 // This cpu booted in EL1
|
|
isb
|
|
ret
|
|
|
|
2:
|
|
#ifdef CONFIG_ARM64_VHE
|
|
/*
|
|
* Check for VHE being present. For the rest of the EL2 setup,
|
|
* x2 being non-zero indicates that we do have VHE, and that the
|
|
* kernel is intended to run at EL2.
|
|
*/
|
|
mrs x2, id_aa64mmfr1_el1
|
|
ubfx x2, x2, #8, #4
|
|
#else
|
|
mov x2, xzr
|
|
#endif
|
|
|
|
/* Hyp configuration. */
|
|
mov x0, #HCR_RW // 64-bit EL1
|
|
cbz x2, set_hcr
|
|
orr x0, x0, #HCR_TGE // Enable Host Extensions
|
|
orr x0, x0, #HCR_E2H
|
|
set_hcr:
|
|
msr hcr_el2, x0
|
|
isb
|
|
|
|
/*
|
|
* Allow Non-secure EL1 and EL0 to access physical timer and counter.
|
|
* This is not necessary for VHE, since the host kernel runs in EL2,
|
|
* and EL0 accesses are configured in the later stage of boot process.
|
|
* Note that when HCR_EL2.E2H == 1, CNTHCTL_EL2 has the same bit layout
|
|
* as CNTKCTL_EL1, and CNTKCTL_EL1 accessing instructions are redefined
|
|
* to access CNTHCTL_EL2. This allows the kernel designed to run at EL1
|
|
* to transparently mess with the EL0 bits via CNTKCTL_EL1 access in
|
|
* EL2.
|
|
*/
|
|
cbnz x2, 1f
|
|
mrs x0, cnthctl_el2
|
|
orr x0, x0, #3 // Enable EL1 physical timers
|
|
msr cnthctl_el2, x0
|
|
1:
|
|
msr cntvoff_el2, xzr // Clear virtual offset
|
|
|
|
#ifdef CONFIG_ARM_GIC_V3
|
|
/* GICv3 system register access */
|
|
mrs x0, id_aa64pfr0_el1
|
|
ubfx x0, x0, #24, #4
|
|
cmp x0, #1
|
|
b.ne 3f
|
|
|
|
mrs_s x0, ICC_SRE_EL2
|
|
orr x0, x0, #ICC_SRE_EL2_SRE // Set ICC_SRE_EL2.SRE==1
|
|
orr x0, x0, #ICC_SRE_EL2_ENABLE // Set ICC_SRE_EL2.Enable==1
|
|
msr_s ICC_SRE_EL2, x0
|
|
isb // Make sure SRE is now set
|
|
mrs_s x0, ICC_SRE_EL2 // Read SRE back,
|
|
tbz x0, #0, 3f // and check that it sticks
|
|
msr_s ICH_HCR_EL2, xzr // Reset ICC_HCR_EL2 to defaults
|
|
|
|
3:
|
|
#endif
|
|
|
|
/* Populate ID registers. */
|
|
mrs x0, midr_el1
|
|
mrs x1, mpidr_el1
|
|
msr vpidr_el2, x0
|
|
msr vmpidr_el2, x1
|
|
|
|
/*
|
|
* When VHE is not in use, early init of EL2 and EL1 needs to be
|
|
* done here.
|
|
* When VHE _is_ in use, EL1 will not be used in the host and
|
|
* requires no configuration, and all non-hyp-specific EL2 setup
|
|
* will be done via the _EL1 system register aliases in __cpu_setup.
|
|
*/
|
|
cbnz x2, 1f
|
|
|
|
/* sctlr_el1 */
|
|
mov x0, #0x0800 // Set/clear RES{1,0} bits
|
|
CPU_BE( movk x0, #0x33d0, lsl #16 ) // Set EE and E0E on BE systems
|
|
CPU_LE( movk x0, #0x30d0, lsl #16 ) // Clear EE and E0E on LE systems
|
|
msr sctlr_el1, x0
|
|
|
|
/* Coprocessor traps. */
|
|
mov x0, #0x33ff
|
|
msr cptr_el2, x0 // Disable copro. traps to EL2
|
|
1:
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
msr hstr_el2, xzr // Disable CP15 traps to EL2
|
|
#endif
|
|
|
|
/* EL2 debug */
|
|
mrs x0, id_aa64dfr0_el1 // Check ID_AA64DFR0_EL1 PMUVer
|
|
sbfx x0, x0, #8, #4
|
|
cmp x0, #1
|
|
b.lt 4f // Skip if no PMU present
|
|
mrs x0, pmcr_el0 // Disable debug access traps
|
|
ubfx x0, x0, #11, #5 // to EL2 and allow access to
|
|
4:
|
|
csel x0, xzr, x0, lt // all PMU counters from EL1
|
|
msr mdcr_el2, x0 // (if they exist)
|
|
|
|
/* Stage-2 translation */
|
|
msr vttbr_el2, xzr
|
|
|
|
cbz x2, install_el2_stub
|
|
|
|
mov w0, #BOOT_CPU_MODE_EL2 // This CPU booted in EL2
|
|
isb
|
|
ret
|
|
|
|
install_el2_stub:
|
|
/* Hypervisor stub */
|
|
adrp x0, __hyp_stub_vectors
|
|
add x0, x0, #:lo12:__hyp_stub_vectors
|
|
msr vbar_el2, x0
|
|
|
|
/* spsr */
|
|
mov x0, #(PSR_F_BIT | PSR_I_BIT | PSR_A_BIT | PSR_D_BIT |\
|
|
PSR_MODE_EL1h)
|
|
msr spsr_el2, x0
|
|
msr elr_el2, lr
|
|
mov w0, #BOOT_CPU_MODE_EL2 // This CPU booted in EL2
|
|
eret
|
|
ENDPROC(el2_setup)
|
|
|
|
/*
|
|
* Sets the __boot_cpu_mode flag depending on the CPU boot mode passed
|
|
* in x20. See arch/arm64/include/asm/virt.h for more info.
|
|
*/
|
|
set_cpu_boot_mode_flag:
|
|
adr_l x1, __boot_cpu_mode
|
|
cmp w0, #BOOT_CPU_MODE_EL2
|
|
b.ne 1f
|
|
add x1, x1, #4
|
|
1: str w0, [x1] // This CPU has booted in EL1
|
|
dmb sy
|
|
dc ivac, x1 // Invalidate potentially stale cache line
|
|
ret
|
|
ENDPROC(set_cpu_boot_mode_flag)
|
|
|
|
/*
|
|
* These values are written with the MMU off, but read with the MMU on.
|
|
* Writers will invalidate the corresponding address, discarding up to a
|
|
* 'Cache Writeback Granule' (CWG) worth of data. The linker script ensures
|
|
* sufficient alignment that the CWG doesn't overlap another section.
|
|
*/
|
|
.pushsection ".mmuoff.data.write", "aw"
|
|
/*
|
|
* We need to find out the CPU boot mode long after boot, so we need to
|
|
* store it in a writable variable.
|
|
*
|
|
* This is not in .bss, because we set it sufficiently early that the boot-time
|
|
* zeroing of .bss would clobber it.
|
|
*/
|
|
ENTRY(__boot_cpu_mode)
|
|
.long BOOT_CPU_MODE_EL2
|
|
.long BOOT_CPU_MODE_EL1
|
|
/*
|
|
* The booting CPU updates the failed status @__early_cpu_boot_status,
|
|
* with MMU turned off.
|
|
*/
|
|
ENTRY(__early_cpu_boot_status)
|
|
.long 0
|
|
|
|
.popsection
|
|
|
|
/*
|
|
* This provides a "holding pen" for platforms to hold all secondary
|
|
* cores are held until we're ready for them to initialise.
|
|
*/
|
|
ENTRY(secondary_holding_pen)
|
|
bl el2_setup // Drop to EL1, w0=cpu_boot_mode
|
|
bl set_cpu_boot_mode_flag
|
|
mrs x0, mpidr_el1
|
|
mov_q x1, MPIDR_HWID_BITMASK
|
|
and x0, x0, x1
|
|
adr_l x3, secondary_holding_pen_release
|
|
pen: ldr x4, [x3]
|
|
cmp x4, x0
|
|
b.eq secondary_startup
|
|
wfe
|
|
b pen
|
|
ENDPROC(secondary_holding_pen)
|
|
|
|
/*
|
|
* Secondary entry point that jumps straight into the kernel. Only to
|
|
* be used where CPUs are brought online dynamically by the kernel.
|
|
*/
|
|
ENTRY(secondary_entry)
|
|
bl el2_setup // Drop to EL1
|
|
bl set_cpu_boot_mode_flag
|
|
b secondary_startup
|
|
ENDPROC(secondary_entry)
|
|
|
|
secondary_startup:
|
|
/*
|
|
* Common entry point for secondary CPUs.
|
|
*/
|
|
bl __cpu_setup // initialise processor
|
|
bl __enable_mmu
|
|
ldr x8, =__secondary_switched
|
|
br x8
|
|
ENDPROC(secondary_startup)
|
|
|
|
__secondary_switched:
|
|
adr_l x5, vectors
|
|
msr vbar_el1, x5
|
|
isb
|
|
|
|
adr_l x0, secondary_data
|
|
ldr x1, [x0, #CPU_BOOT_STACK] // get secondary_data.stack
|
|
mov sp, x1
|
|
ldr x2, [x0, #CPU_BOOT_TASK]
|
|
msr sp_el0, x2
|
|
mov x29, #0
|
|
b secondary_start_kernel
|
|
ENDPROC(__secondary_switched)
|
|
|
|
/*
|
|
* The booting CPU updates the failed status @__early_cpu_boot_status,
|
|
* with MMU turned off.
|
|
*
|
|
* update_early_cpu_boot_status tmp, status
|
|
* - Corrupts tmp1, tmp2
|
|
* - Writes 'status' to __early_cpu_boot_status and makes sure
|
|
* it is committed to memory.
|
|
*/
|
|
|
|
.macro update_early_cpu_boot_status status, tmp1, tmp2
|
|
mov \tmp2, #\status
|
|
adr_l \tmp1, __early_cpu_boot_status
|
|
str \tmp2, [\tmp1]
|
|
dmb sy
|
|
dc ivac, \tmp1 // Invalidate potentially stale cache line
|
|
.endm
|
|
|
|
/*
|
|
* Enable the MMU.
|
|
*
|
|
* x0 = SCTLR_EL1 value for turning on the MMU.
|
|
*
|
|
* Returns to the caller via x30/lr. This requires the caller to be covered
|
|
* by the .idmap.text section.
|
|
*
|
|
* Checks if the selected granule size is supported by the CPU.
|
|
* If it isn't, park the CPU
|
|
*/
|
|
ENTRY(__enable_mmu)
|
|
mrs x1, ID_AA64MMFR0_EL1
|
|
ubfx x2, x1, #ID_AA64MMFR0_TGRAN_SHIFT, 4
|
|
cmp x2, #ID_AA64MMFR0_TGRAN_SUPPORTED
|
|
b.ne __no_granule_support
|
|
update_early_cpu_boot_status 0, x1, x2
|
|
adrp x1, idmap_pg_dir
|
|
adrp x2, swapper_pg_dir
|
|
msr ttbr0_el1, x1 // load TTBR0
|
|
msr ttbr1_el1, x2 // load TTBR1
|
|
isb
|
|
msr sctlr_el1, x0
|
|
isb
|
|
/*
|
|
* Invalidate the local I-cache so that any instructions fetched
|
|
* speculatively from the PoC are discarded, since they may have
|
|
* been dynamically patched at the PoU.
|
|
*/
|
|
ic iallu
|
|
dsb nsh
|
|
isb
|
|
ret
|
|
ENDPROC(__enable_mmu)
|
|
|
|
__no_granule_support:
|
|
/* Indicate that this CPU can't boot and is stuck in the kernel */
|
|
update_early_cpu_boot_status CPU_STUCK_IN_KERNEL, x1, x2
|
|
1:
|
|
wfe
|
|
wfi
|
|
b 1b
|
|
ENDPROC(__no_granule_support)
|
|
|
|
#ifdef CONFIG_RELOCATABLE
|
|
__relocate_kernel:
|
|
/*
|
|
* Iterate over each entry in the relocation table, and apply the
|
|
* relocations in place.
|
|
*/
|
|
ldr w9, =__rela_offset // offset to reloc table
|
|
ldr w10, =__rela_size // size of reloc table
|
|
|
|
mov_q x11, KIMAGE_VADDR // default virtual offset
|
|
add x11, x11, x23 // actual virtual offset
|
|
add x9, x9, x11 // __va(.rela)
|
|
add x10, x9, x10 // __va(.rela) + sizeof(.rela)
|
|
|
|
0: cmp x9, x10
|
|
b.hs 1f
|
|
ldp x11, x12, [x9], #24
|
|
ldr x13, [x9, #-8]
|
|
cmp w12, #R_AARCH64_RELATIVE
|
|
b.ne 0b
|
|
add x13, x13, x23 // relocate
|
|
str x13, [x11, x23]
|
|
b 0b
|
|
1: ret
|
|
ENDPROC(__relocate_kernel)
|
|
#endif
|
|
|
|
__primary_switch:
|
|
#ifdef CONFIG_RANDOMIZE_BASE
|
|
mov x19, x0 // preserve new SCTLR_EL1 value
|
|
mrs x20, sctlr_el1 // preserve old SCTLR_EL1 value
|
|
#endif
|
|
|
|
bl __enable_mmu
|
|
#ifdef CONFIG_RELOCATABLE
|
|
bl __relocate_kernel
|
|
#ifdef CONFIG_RANDOMIZE_BASE
|
|
ldr x8, =__primary_switched
|
|
adrp x0, __PHYS_OFFSET
|
|
blr x8
|
|
|
|
/*
|
|
* If we return here, we have a KASLR displacement in x23 which we need
|
|
* to take into account by discarding the current kernel mapping and
|
|
* creating a new one.
|
|
*/
|
|
msr sctlr_el1, x20 // disable the MMU
|
|
isb
|
|
bl __create_page_tables // recreate kernel mapping
|
|
|
|
tlbi vmalle1 // Remove any stale TLB entries
|
|
dsb nsh
|
|
|
|
msr sctlr_el1, x19 // re-enable the MMU
|
|
isb
|
|
ic iallu // flush instructions fetched
|
|
dsb nsh // via old mapping
|
|
isb
|
|
|
|
bl __relocate_kernel
|
|
#endif
|
|
#endif
|
|
ldr x8, =__primary_switched
|
|
adrp x0, __PHYS_OFFSET
|
|
br x8
|
|
ENDPROC(__primary_switch)
|