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81a0bc39ea
This patch adds EFI stub support for the ARM Linux kernel. The EFI stub operates similarly to the x86 and arm64 stubs: it is a shim between the EFI firmware and the normal zImage entry point, and sets up the environment that the zImage is expecting. This includes optionally loading the initrd and device tree from the system partition based on the kernel command line. Signed-off-by: Roy Franz <roy.franz@linaro.org> Tested-by: Ryan Harkin <ryan.harkin@linaro.org> Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
131 lines
3.8 KiB
ArmAsm
131 lines
3.8 KiB
ArmAsm
/*
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* Copyright (C) 2013-2015 Linaro Ltd
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* Authors: Roy Franz <roy.franz@linaro.org>
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* Ard Biesheuvel <ard.biesheuvel@linaro.org>
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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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.macro __nop
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#ifdef CONFIG_EFI_STUB
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@ This is almost but not quite a NOP, since it does clobber the
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@ condition flags. But it is the best we can do for EFI, since
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@ PE/COFF expects the magic string "MZ" at offset 0, while the
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@ ARM/Linux boot protocol expects an executable instruction
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@ there.
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.inst 'M' | ('Z' << 8) | (0x1310 << 16) @ tstne r0, #0x4d000
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#else
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mov r0, r0
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#endif
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.endm
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.macro __EFI_HEADER
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#ifdef CONFIG_EFI_STUB
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b __efi_start
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.set start_offset, __efi_start - start
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.org start + 0x3c
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@
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@ The PE header can be anywhere in the file, but for
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@ simplicity we keep it together with the MSDOS header
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@ The offset to the PE/COFF header needs to be at offset
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@ 0x3C in the MSDOS header.
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@ The only 2 fields of the MSDOS header that are used are this
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@ PE/COFF offset, and the "MZ" bytes at offset 0x0.
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@
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.long pe_header - start @ Offset to the PE header.
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pe_header:
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.ascii "PE\0\0"
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coff_header:
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.short 0x01c2 @ ARM or Thumb
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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
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@ SizeOfOptionalHeader
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.short 0x306 @ Characteristics.
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@ IMAGE_FILE_32BIT_MACHINE |
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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 0x10b @ PE32 format
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.byte 0x02 @ MajorLinkerVersion
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.byte 0x14 @ MinorLinkerVersion
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.long _end - __efi_start @ SizeOfCode
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.long 0 @ SizeOfInitializedData
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.long 0 @ SizeOfUninitializedData
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.long efi_stub_entry - start @ AddressOfEntryPoint
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.long start_offset @ BaseOfCode
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.long 0 @ data
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extra_header_fields:
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.long 0 @ ImageBase
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.long 0x200 @ SectionAlignment
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.long 0x200 @ 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 - start @ SizeOfImage
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.long start_offset @ 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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.long 0 @ SizeOfStackReserve
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.long 0 @ SizeOfStackCommit
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.long 0 @ SizeOfHeapReserve
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.long 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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@
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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\0\0"
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.long 0 @ VirtualSize
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.long 0 @ VirtualAddress
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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
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.ascii ".text\0\0\0"
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.long _end - __efi_start @ VirtualSize
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.long __efi_start @ VirtualAddress
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.long _edata - __efi_start @ SizeOfRawData
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.long __efi_start @ 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 0xe0500020 @ Characteristics
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.align 9
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__efi_start:
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#endif
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.endm
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