[PATCH v2 12/14] arm: efi: replace open coded constants with symbolic ones

Ard Biesheuvel
2017-02-08T11:55:45Z

Replace the various open coded constants in the EFI PE/COFF header with
definitions from pe.h, or expressions based on local symbols.

Note that this patch also changes the indentation to make room for the
symbolic constant names.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
arch/arm/boot/compressed/efi-header.S | 172 ++++++++++----------
1 file changed, 89 insertions(+), 83 deletions(-)

diff --git a/arch/arm/boot/compressed/efi-header.S b/arch/arm/boot/compressed/efi-header.S
index 5873fc2b5f9a..7ff2b2f05e4c 100644
--- a/arch/arm/boot/compressed/efi-header.S
+++ b/arch/arm/boot/compressed/efi-header.S
@@ -1,5 +1,5 @@
/*
- * Copyright (C) 2013-2015 Linaro Ltd
+ * Copyright (C) 2013-2017 Linaro Ltd
* Authors: Roy Franz <roy.franz@linaro.org>
* Ard Biesheuvel <ard.biesheuvel@linaro.org>
*
@@ -8,105 +8,111 @@
* published by the Free Software Foundation.
*/

- .macro __nop
+#include <linux/pe.h>
+#include <linux/sizes.h>
+
+ .macro __nop
#ifdef CONFIG_EFI_STUB
- @ This is almost but not quite a NOP, since it does clobber the
- @ condition flags. But it is the best we can do for EFI, since
- @ PE/COFF expects the magic string "MZ" at offset 0, while the
- @ ARM/Linux boot protocol expects an executable instruction
- @ there.
- .inst 'M' | ('Z' << 8) | (0x1310 << 16) @ tstne r0, #0x4d000
+ @ This is almost but not quite a NOP, since it does clobber the
+ @ condition flags. But it is the best we can do for EFI, since
+ @ PE/COFF expects the magic string "MZ" at offset 0, while the
+ @ ARM/Linux boot protocol expects an executable instruction
+ @ there.
+ .inst MZ_MAGIC | (0x1310 << 16) @ tstne r0, #0x4d000
#else
- mov r0, r0
+ mov r0, r0
#endif
- .endm
+ .endm

- .macro __EFI_HEADER
+ .macro __EFI_HEADER
#ifdef CONFIG_EFI_STUB
- .set start_offset, __efi_start - start
- .org start + 0x3c
- @
- @ The PE header can be anywhere in the file, but for
- @ simplicity we keep it together with the MSDOS header
- @ The offset to the PE/COFF header needs to be at offset
- @ 0x3C in the MSDOS header.
- @ The only 2 fields of the MSDOS header that are used are this
- @ PE/COFF offset, and the "MZ" bytes at offset 0x0.
- @
- .long pe_header - start @ Offset to the PE header.
+ .set start_offset, __efi_start - start
+ .org start + 0x3c
+ @
+ @ The PE header can be anywhere in the file, but for
+ @ simplicity we keep it together with the MSDOS header
+ @ The offset to the PE/COFF header needs to be at offset
+ @ 0x3C in the MSDOS header.
+ @ The only 2 fields of the MSDOS header that are used are this
+ @ PE/COFF offset, and the "MZ" bytes at offset 0x0.
+ @
+ .long pe_header - start @ Offset to the PE header.

pe_header:
- .ascii "PE\0\0"
+ .long PE_MAGIC

coff_header:
- .short 0x01c2 @ ARM or Thumb
- .short 1 @ nr_sections
- .long 0 @ TimeDateStamp
- .long 0 @ PointerToSymbolTable
- .long 0 @ NumberOfSymbols
- .short section_table - optional_header
- @ SizeOfOptionalHeader
- .short 0x306 @ Characteristics.
- @ IMAGE_FILE_32BIT_MACHINE |
- @ IMAGE_FILE_DEBUG_STRIPPED |
- @ IMAGE_FILE_EXECUTABLE_IMAGE |
- @ IMAGE_FILE_LINE_NUMS_STRIPPED
+ .short IMAGE_FILE_MACHINE_THUMB @ Machine
+ .short section_count @ NumberOfSections
+ .long 0 @ TimeDateStamp
+ .long 0 @ PointerToSymbolTable
+ .long 0 @ NumberOfSymbols
+ .short section_table - optional_header @ SizeOfOptionalHeader
+ .short IMAGE_FILE_32BIT_MACHINE | \
+ IMAGE_FILE_DEBUG_STRIPPED | \
+ IMAGE_FILE_EXECUTABLE_IMAGE | \
+ IMAGE_FILE_LINE_NUMS_STRIPPED @ Characteristics

optional_header:
- .short 0x10b @ PE32 format
- .byte 0x02 @ MajorLinkerVersion
- .byte 0x14 @ MinorLinkerVersion
- .long _end - __efi_start @ SizeOfCode
- .long 0 @ SizeOfInitializedData
- .long 0 @ SizeOfUninitializedData
- .long efi_stub_entry - start @ AddressOfEntryPoint
- .long start_offset @ BaseOfCode
- .long 0 @ data
+ .short PE_OPT_MAGIC_PE32 @ PE32 format
+ .byte 0x02 @ MajorLinkerVersion
+ .byte 0x14 @ MinorLinkerVersion
+ .long _end - __efi_start @ SizeOfCode
+ .long 0 @ SizeOfInitializedData
+ .long 0 @ SizeOfUninitializedData
+ .long efi_stub_entry - start @ AddressOfEntryPoint
+ .long start_offset @ BaseOfCode
+ .long 0 @ BaseOfData

extra_header_fields:
- .long 0 @ ImageBase
- .long 0x200 @ SectionAlignment
- .long 0x200 @ FileAlignment
- .short 0 @ MajorOperatingSystemVersion
- .short 0 @ MinorOperatingSystemVersion
- .short 0 @ MajorImageVersion
- .short 0 @ MinorImageVersion
- .short 0 @ MajorSubsystemVersion
- .short 0 @ MinorSubsystemVersion
- .long 0 @ Win32VersionValue
+ .long 0 @ ImageBase
+ .long SZ_512 @ SectionAlignment
+ .long SZ_512 @ FileAlignment
+ .short 0 @ MajorOsVersion
+ .short 0 @ MinorOsVersion
+ .short 0 @ MajorImageVersion
+ .short 0 @ MinorImageVersion
+ .short 0 @ MajorSubsystemVersion
+ .short 0 @ MinorSubsystemVersion
+ .long 0 @ Win32VersionValue

- .long _end - start @ SizeOfImage
- .long start_offset @ SizeOfHeaders
- .long 0 @ CheckSum
- .short 0xa @ Subsystem (EFI application)
- .short 0 @ DllCharacteristics
- .long 0 @ SizeOfStackReserve
- .long 0 @ SizeOfStackCommit
- .long 0 @ SizeOfHeapReserve
- .long 0 @ SizeOfHeapCommit
- .long 0 @ LoaderFlags
- .long 0x6 @ NumberOfRvaAndSizes
+ .long _end - start @ SizeOfImage
+ .long start_offset @ SizeOfHeaders
+ .long 0 @ CheckSum
+ .short IMAGE_SUBSYSTEM_EFI_APPLICATION @ Subsystem
+ .short 0 @ DllCharacteristics
+ .long 0 @ SizeOfStackReserve
+ .long 0 @ SizeOfStackCommit
+ .long 0 @ SizeOfHeapReserve
+ .long 0 @ SizeOfHeapCommit
+ .long 0 @ LoaderFlags
+ .long (section_table - .) / 8 @ NumberOfRvaAndSizes

- .quad 0 @ ExportTable
- .quad 0 @ ImportTable
- .quad 0 @ ResourceTable
- .quad 0 @ ExceptionTable
- .quad 0 @ CertificationTable
- .quad 0 @ BaseRelocationTable
+ .quad 0 @ ExportTable
+ .quad 0 @ ImportTable
+ .quad 0 @ ResourceTable
+ .quad 0 @ ExceptionTable
+ .quad 0 @ CertificationTable
+ .quad 0 @ BaseRelocationTable

section_table:
- .ascii ".text\0\0\0"
- .long _end - __efi_start @ VirtualSize
- .long __efi_start @ VirtualAddress
- .long _edata - __efi_start @ SizeOfRawData
- .long __efi_start @ PointerToRawData
- .long 0 @ PointerToRelocations
- .long 0 @ PointerToLineNumbers
- .short 0 @ NumberOfRelocations
- .short 0 @ NumberOfLineNumbers
- .long 0xe0000020 @ Characteristics
+ .ascii ".text\0\0\0"
+ .long _end - __efi_start @ VirtualSize
+ .long __efi_start @ VirtualAddress
+ .long _edata - __efi_start @ SizeOfRawData
+ .long __efi_start @ PointerToRawData
+ .long 0 @ PointerToRelocations
+ .long 0 @ PointerToLineNumbers
+ .short 0 @ NumberOfRelocations
+ .short 0 @ NumberOfLineNumbers
+ .long IMAGE_SCN_CNT_CODE | \
+ IMAGE_SCN_MEM_READ | \
+ IMAGE_SCN_MEM_WRITE | \
+ IMAGE_SCN_MEM_EXECUTE @ Characteristics
+
+ .set section_count, (. - section_table) / 40

- .align 9
+ .align 9
__efi_start:
#endif
- .endm
+ .endm
--
2.7.4