arch/riscv/lib/crt0_riscv_efi.S

   1 /* SPDX-License-Identifier: GPL-2.0+ */
   2 /*
   3  * crt0-efi-riscv.S - PE/COFF header for RISC-V EFI applications
   4  *
   5  * Copright (C) 2014 Linaro Ltd. <ard.biesheuvel@linaro.org>
   6  * Copright (C) 2018 Alexander Graf <agraf@suse.de>
   7  *
   8  * This file is inspired by arch/arm/lib/crt0_aarch64_efi.S
   9  */
  10
  11 #include <asm-generic/pe.h>
  12
  13 #if __riscv_xlen == 64
  14 #define SIZE_LONG       8
  15 #define SAVE_LONG(reg, idx)     sd      reg, (idx*SIZE_LONG)(sp)
  16 #define LOAD_LONG(reg, idx)     ld      reg, (idx*SIZE_LONG)(sp)
  17 #define PE_MACHINE      IMAGE_FILE_MACHINE_RISCV64
  18 #else
  19 #define SIZE_LONG       4
  20 #define SAVE_LONG(reg, idx)     sw      reg, (idx*SIZE_LONG)(sp)
  21 #define LOAD_LONG(reg, idx)     lw      reg, (idx*SIZE_LONG)(sp)
  22 #define PE_MACHINE      IMAGE_FILE_MACHINE_RISCV32
  23 #endif
  24
  25
  26         .section        .text.head
  27
  28         /*
  29          * Magic "MZ" signature for PE/COFF
  30          */
  31         .globl  ImageBase
  32 ImageBase:
  33         .short  IMAGE_DOS_SIGNATURE             /* 'MZ' */
  34         .skip   58                              /* 'MZ' + pad + offset == 64 */
  35         .long   pe_header - ImageBase           /* Offset to the PE header */
  36 pe_header:
  37         .long   IMAGE_NT_SIGNATURE              /* 'PE' */
  38 coff_header:
  39         .short  PE_MACHINE                      /* RISC-V 64/32-bit */
  40         .short  2                               /* nr_sections */
  41         .long   0                               /* TimeDateStamp */
  42         .long   0                               /* PointerToSymbolTable */
  43         .long   0                               /* NumberOfSymbols */
  44         .short  section_table - optional_header /* SizeOfOptionalHeader */
  45         /* Characteristics */
  46         .short  (IMAGE_FILE_EXECUTABLE_IMAGE | \
  47                  IMAGE_FILE_LINE_NUMS_STRIPPED | \
  48                  IMAGE_FILE_LOCAL_SYMS_STRIPPED | \
  49                  IMAGE_FILE_DEBUG_STRIPPED)
  50 optional_header:
  51         .short  IMAGE_NT_OPTIONAL_HDR64_MAGIC   /* PE32+ format */
  52         .byte   0x02                            /* MajorLinkerVersion */
  53         .byte   0x14                            /* MinorLinkerVersion */
  54         .long   _edata - _start                 /* SizeOfCode */
  55         .long   0                               /* SizeOfInitializedData */
  56         .long   0                               /* SizeOfUninitializedData */
  57         .long   _start - ImageBase              /* AddressOfEntryPoint */
  58         .long   _start - ImageBase              /* BaseOfCode */
  59
  60 extra_header_fields:
  61         .quad   0                               /* ImageBase */
  62         .long   0x20                            /* SectionAlignment */
  63         .long   0x8                             /* FileAlignment */
  64         .short  0                               /* MajorOperatingSystemVersion */
  65         .short  0                               /* MinorOperatingSystemVersion */
  66         .short  0                               /* MajorImageVersion */
  67         .short  0                               /* MinorImageVersion */
  68         .short  0                               /* MajorSubsystemVersion */
  69         .short  0                               /* MinorSubsystemVersion */
  70         .long   0                               /* Win32VersionValue */
  71
  72         .long   _edata - ImageBase              /* SizeOfImage */
  73
  74         /*
  75          * Everything before the kernel image is considered part of the header
  76          */
  77         .long   _start - ImageBase              /* SizeOfHeaders */
  78         .long   0                               /* CheckSum */
  79         .short  IMAGE_SUBSYSTEM_EFI_APPLICATION /* Subsystem */
  80         .short  0                               /* DllCharacteristics */
  81         .quad   0                               /* SizeOfStackReserve */
  82         .quad   0                               /* SizeOfStackCommit */
  83         .quad   0                               /* SizeOfHeapReserve */
  84         .quad   0                               /* SizeOfHeapCommit */
  85         .long   0                               /* LoaderFlags */
  86         .long   0x6                             /* NumberOfRvaAndSizes */
  87
  88         .quad   0                               /* ExportTable */
  89         .quad   0                               /* ImportTable */
  90         .quad   0                               /* ResourceTable */
  91         .quad   0                               /* ExceptionTable */
  92         .quad   0                               /* CertificationTable */
  93         .quad   0                               /* BaseRelocationTable */
  94
  95         /* Section table */
  96 section_table:
  97
  98         /*
  99          * The EFI application loader requires a relocation section
 100          * because EFI applications must be relocatable.  This is a
 101          * dummy section as far as we are concerned.
 102          */
 103         .ascii  ".reloc"
 104         .byte   0
 105         .byte   0                       /* end of 0 padding of section name */
 106         .long   0
 107         .long   0
 108         .long   0                       /* SizeOfRawData */
 109         .long   0                       /* PointerToRawData */
 110         .long   0                       /* PointerToRelocations */
 111         .long   0                       /* PointerToLineNumbers */
 112         .short  0                       /* NumberOfRelocations */
 113         .short  0                       /* NumberOfLineNumbers */
 114         .long   0x42100040              /* Characteristics (section flags) */
 115
 116
 117         .ascii  ".text"
 118         .byte   0
 119         .byte   0
 120         .byte   0                       /* end of 0 padding of section name */
 121         .long   _edata - _start         /* VirtualSize */
 122         .long   _start - ImageBase      /* VirtualAddress */
 123         .long   _edata - _start         /* SizeOfRawData */
 124         .long   _start - ImageBase      /* PointerToRawData */
 125
 126         .long   0               /* PointerToRelocations (0 for executables) */
 127         .long   0               /* PointerToLineNumbers (0 for executables) */
 128         .short  0               /* NumberOfRelocations  (0 for executables) */
 129         .short  0               /* NumberOfLineNumbers  (0 for executables) */
 130         .long   0xe0500020      /* Characteristics (section flags) */
 131
 132 _start:
 133         addi            sp, sp, -(SIZE_LONG * 3)
 134         SAVE_LONG(a0, 0)
 135         SAVE_LONG(a1, 1)
 136         SAVE_LONG(ra, 2)
 137
 138         lla             a0, ImageBase
 139         lla             a1, _DYNAMIC
 140         call            _relocate
 141         bne             a0, zero, 0f
 142
 143         LOAD_LONG(a1, 1)
 144         LOAD_LONG(a0, 0)
 145         call            efi_main
 146
 147         LOAD_LONG(ra, 2)
 148
 149 0:      addi            sp, sp, (SIZE_LONG * 3)
 150         ret