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