arch/arm/lib/crt0_arm_efi.S

   1 /*
   2  * crt0-efi-arm.S - PE/COFF header for ARM EFI applications
   3  *
   4  * Copright (C) 2014 Linaro Ltd. <ard.biesheuvel@linaro.org>
   5  *
   6  * SPDX-License-Identifier:     GPL-2.0+     BSD-2-Clause
   7  *
   8  * This file is taken and modified from the gnu-efi project.
   9  */
  10
  11 #include <asm-generic/pe.h>
  12
  13         .section        .text.head
  14
  15         /*
  16          * Magic "MZ" signature for PE/COFF
  17          */
  18         .globl  image_base
  19 image_base:
  20         .ascii  "MZ"
  21         .skip   58                              /* 'MZ' + pad + offset == 64 */
  22         .long   pe_header - image_base          /* Offset to the PE header */
  23 pe_header:
  24         .ascii  "PE"
  25         .short  0
  26 coff_header:
  27         .short  0x1c2                           /* Mixed ARM/Thumb */
  28         .short  2                               /* nr_sections */
  29         .long   0                               /* TimeDateStamp */
  30         .long   0                               /* PointerToSymbolTable */
  31         .long   1                               /* NumberOfSymbols */
  32         .short  section_table - optional_header /* SizeOfOptionalHeader */
  33         /*
  34          * Characteristics: IMAGE_FILE_32BIT_MACHINE |
  35          * IMAGE_FILE_DEBUG_STRIPPED | IMAGE_FILE_EXECUTABLE_IMAGE |
  36          * IMAGE_FILE_LINE_NUMS_STRIPPED
  37          */
  38         .short  0x306
  39 optional_header:
  40         .short  0x10b                           /* PE32+ format */
  41         .byte   0x02                            /* MajorLinkerVersion */
  42         .byte   0x14                            /* MinorLinkerVersion */
  43         .long   _edata - _start                 /* SizeOfCode */
  44         .long   0                               /* SizeOfInitializedData */
  45         .long   0                               /* SizeOfUninitializedData */
  46         .long   _start - image_base             /* AddressOfEntryPoint */
  47         .long   _start - image_base             /* BaseOfCode */
  48         .long   0                               /* BaseOfData */
  49
  50 extra_header_fields:
  51         .long   0                               /* image_base */
  52         .long   0x20                            /* SectionAlignment */
  53         .long   0x8                             /* FileAlignment */
  54         .short  0                               /* MajorOperatingSystemVersion */
  55         .short  0                               /* MinorOperatingSystemVersion */
  56         .short  0                               /* MajorImageVersion */
  57         .short  0                               /* MinorImageVersion */
  58         .short  0                               /* MajorSubsystemVersion */
  59         .short  0                               /* MinorSubsystemVersion */
  60         .long   0                               /* Win32VersionValue */
  61
  62         .long   _edata - image_base             /* SizeOfImage */
  63
  64         /*
  65          * Everything before the kernel image is considered part of the header
  66          */
  67         .long   _start - image_base             /* SizeOfHeaders */
  68         .long   0                               /* CheckSum */
  69         .short  IMAGE_SUBSYSTEM_EFI_APPLICATION /* Subsystem */
  70         .short  0                               /* DllCharacteristics */
  71         .long   0                               /* SizeOfStackReserve */
  72         .long   0                               /* SizeOfStackCommit */
  73         .long   0                               /* SizeOfHeapReserve */
  74         .long   0                               /* SizeOfHeapCommit */
  75         .long   0                               /* LoaderFlags */
  76         .long   0x6                             /* NumberOfRvaAndSizes */
  77
  78         .quad   0                               /* ExportTable */
  79         .quad   0                               /* ImportTable */
  80         .quad   0                               /* ResourceTable */
  81         .quad   0                               /* ExceptionTable */
  82         .quad   0                               /* CertificationTable */
  83         .quad   0                               /* BaseRelocationTable */
  84
  85 section_table:
  86
  87         /*
  88          * The EFI application loader requires a relocation section
  89          * because EFI applications must be relocatable.  This is a
  90          * dummy section as far as we are concerned.
  91          */
  92         .ascii  ".reloc"
  93         .byte   0
  94         .byte   0                       /* end of 0 padding of section name */
  95         .long   0
  96         .long   0
  97         .long   0                       /* SizeOfRawData */
  98         .long   0                       /* PointerToRawData */
  99         .long   0                       /* PointerToRelocations */
 100         .long   0                       /* PointerToLineNumbers */
 101         .short  0                       /* NumberOfRelocations */
 102         .short  0                       /* NumberOfLineNumbers */
 103         .long   0x42100040              /* Characteristics (section flags) */
 104
 105         .ascii  ".text"
 106         .byte   0
 107         .byte   0
 108         .byte   0                       /* end of 0 padding of section name */
 109         .long   _edata - _start         /* VirtualSize */
 110         .long   _start - image_base     /* VirtualAddress */
 111         .long   _edata - _start         /* SizeOfRawData */
 112         .long   _start - image_base     /* PointerToRawData */
 113
 114         .long   0               /* PointerToRelocations (0 for executables) */
 115         .long   0               /* PointerToLineNumbers (0 for executables) */
 116         .short  0               /* NumberOfRelocations  (0 for executables) */
 117         .short  0               /* NumberOfLineNumbers  (0 for executables) */
 118         .long   0xe0500020      /* Characteristics (section flags) */
 119
 120 _start:
 121         stmfd           sp!, {r0-r2, lr}
 122
 123         mov             r2, r0
 124         mov             r3, r1
 125         adr             r1, .L_DYNAMIC
 126         ldr             r0, [r1]
 127         add             r1, r0, r1
 128         adr             r0, image_base
 129         bl              _relocate
 130         teq             r0, #0
 131         bne             0f
 132
 133         ldmfd           sp, {r0-r1}
 134         bl              efi_main
 135
 136 0:      add             sp, sp, #12
 137         ldr             pc, [sp], #4
 138
 139 .L_DYNAMIC:
 140         .word           _DYNAMIC - .