utils/sbtools/elf.h

   1 #include <stdio.h>
   2 #include <stdint.h>
   3 #include <string.h>
   4 #include <stdbool.h>
   5 #include <stdlib.h>
   6 #include <unistd.h>
   7
   8 /**
   9  * Definitions
  10  *   taken from elf.h linux header
  11  *   based on ELF specification
  12  *   based on ARM ELF specification
  13  */
  14 typedef uint16_t Elf32_Half;
  15
  16 typedef uint32_t Elf32_Word;
  17 typedef int32_t  Elf32_Sword;
  18 typedef uint32_t Elf32_Addr;
  19 typedef uint32_t Elf32_Off;
  20 typedef uint16_t Elf32_Section;
  21
  22 #define EI_NIDENT   16
  23
  24 typedef struct
  25 {
  26     unsigned char   e_ident[EI_NIDENT]; /* Magic number and other info */
  27     Elf32_Half      e_type; /* Object file type */
  28     Elf32_Half      e_machine; /* Architecture */
  29     Elf32_Word      e_version; /* Object file version */
  30     Elf32_Addr      e_entry; /* Entry point virtual address */
  31     Elf32_Off       e_phoff; /* Program header table file offset */
  32     Elf32_Off       e_shoff; /* Section header table file offset */
  33     Elf32_Word      e_flags; /* Processor-specific flags */
  34     Elf32_Half      e_ehsize; /* ELF header size in bytes */
  35     Elf32_Half      e_phentsize; /* Program header table entry size */
  36     Elf32_Half      e_phnum; /* Program header table entry count */
  37     Elf32_Half      e_shentsize; /* Section header table entry size */
  38     Elf32_Half      e_shnum; /* Section header table entry count */
  39     Elf32_Half      e_shstrndx; /* Section header string table index */
  40 }Elf32_Ehdr;
  41
  42 #define EI_MAG0     0 /* File identification byte 0 index */
  43 #define ELFMAG0     0x7f /* Magic number byte 0 */
  44
  45 #define EI_MAG1     1 /* File identification byte 1 index */
  46 #define ELFMAG1     'E' /* Magic number byte 1 */
  47
  48 #define EI_MAG2     2 /* File identification byte 2 index */
  49 #define ELFMAG2     'L' /* Magic number byte 2 */
  50
  51 #define EI_MAG3     3 /* File identification byte 3 index */
  52 #define ELFMAG3     'F' /* Magic number byte 3 */
  53
  54 #define EI_CLASS    4 /* File class byte index */
  55 #define ELFCLASS32  1 /* 32-bit objects */
  56
  57 #define EI_DATA     5 /* Data encoding byte index */
  58 #define ELFDATA2LSB 1 /* 2's complement, little endian */
  59
  60 #define EI_VERSION  6 /* File version byte index, Value must be EV_CURRENT */
  61
  62 #define EI_OSABI    7 /* OS ABI identification */
  63 #define ELFOSABI_NONE       0 /* UNIX System V ABI */
  64 #define ELFOSABI_ARM_AEABI  64 /* ARM EABI */
  65 #define ELFOSABI_ARM        97 /* ARM */
  66
  67 #define EI_ABIVERSION   8 /* ABI version */
  68
  69 #define EI_PAD      9 /* Byte index of padding bytes */
  70
  71 #define ET_EXEC     2 /* Executable file */
  72
  73 #define EM_ARM      40 /* ARM */
  74
  75 #define EV_CURRENT  1 /* Current version */
  76
  77 #define EF_ARM_HASENTRY     0x00000002
  78
  79 #define SHN_UNDEF   0 /* Undefined section */
  80
  81 typedef struct
  82 {
  83     Elf32_Word  sh_name; /* Section name (string tbl index) */
  84     Elf32_Word  sh_type; /* Section type */
  85     Elf32_Word  sh_flags; /* Section flags */
  86     Elf32_Addr  sh_addr; /* Section virtual addr at execution */
  87     Elf32_Off   sh_offset; /* Section file offset */
  88     Elf32_Word  sh_size; /* Section size in bytes */
  89     Elf32_Word  sh_link; /* Link to another section */
  90     Elf32_Word  sh_info; /* Additional section information */
  91     Elf32_Word  sh_addralign; /* Section alignment */
  92     Elf32_Word  sh_entsize; /* Entry size if section holds table */
  93 }Elf32_Shdr;
  94
  95 #define SHT_NULL            0 /* Section header table entry unused */
  96 #define SHT_PROGBITS        1 /* Program data */
  97 #define SHT_SYMTAB          2 /* Symbol table */
  98 #define SHT_STRTAB          3 /* String table */
  99 #define SHT_RELA            4 /* Relocation entries with addends */
 100 #define SHT_HASH            5 /* Symbol hash table */
 101 #define SHT_DYNAMIC         6 /* Dynamic linking information */
 102 #define SHT_NOTE            7 /* Notes */
 103 #define SHT_NOBITS          8 /* Program space with no data (bss) */
 104 #define SHT_REL             9 /* Relocation entries, no addends */
 105 #define SHT_SHLIB           10 /* Reserved */
 106 #define SHT_DYNSYM          11 /* Dynamic linker symbol table */
 107 #define SHT_INIT_ARRAY      14 /* Array of constructors */
 108 #define SHT_FINI_ARRAY      15 /* Array of destructors */
 109 #define SHT_PREINIT_ARRAY   16 /* Array of pre-constructors */
 110 #define SHT_GROUP           17 /* Section group */
 111 #define SHT_SYMTAB_SHNDX    18 /* Extended section indeces */
 112 #define SHT_NUM             19 /* Number of defined types.  */
 113
 114 #define SHF_WRITE       (1 << 0) /* Writable */
 115 #define SHF_ALLOC       (1 << 1) /* Occupies memory during execution */
 116 #define SHF_EXECINSTR   (1 << 2) /* Executable */
 117 #define SHF_MERGE       (1 << 4) /* Might be merged */
 118 #define SHF_STRINGS     (1 << 5) /* Contains nul-terminated strings */
 119
 120 typedef struct
 121 {
 122     Elf32_Word  p_type; /* Segment type */
 123     Elf32_Off   p_offset; /* Segment file offset */
 124     Elf32_Addr  p_vaddr; /* Segment virtual address */
 125     Elf32_Addr  p_paddr; /* Segment physical address */
 126     Elf32_Word  p_filesz; /* Segment size in file */
 127     Elf32_Word  p_memsz; /* Segment size in memory */
 128     Elf32_Word  p_flags; /* Segment flags */
 129     Elf32_Word  p_align; /* Segment alignment */
 130 }Elf32_Phdr;
 131
 132 #define PT_LOAD     1 /* Loadable program segment */
 133
 134 #define PF_X    (1 << 0) /* Segment is executable */
 135 #define PF_W    (1 << 1) /* Segment is writable */
 136 #define PF_R    (1 << 2) /* Segment is readable */
 137
 138 /**
 139  * API
 140  */
 141 enum elf_section_type_t
 142 {
 143     EST_LOAD,
 144     EST_FILL
 145 };
 146
 147 struct elf_section_t
 148 {
 149     uint32_t addr;
 150     uint32_t size;
 151     enum elf_section_type_t type;
 152     /* <union> */
 153     void *section;
 154     uint32_t pattern;
 155     /* </union> */
 156     struct elf_section_t *next;
 157     /* Internal to elf_output */
 158     uint32_t offset;
 159 };
 160
 161 struct elf_params_t
 162 {
 163     bool has_start_addr;
 164     uint32_t start_addr;
 165     struct elf_section_t *first_section;
 166     struct elf_section_t *last_section;
 167 };
 168
 169 typedef void (*elf_write_fn_t)(void *user, uint32_t addr, const void *buf, size_t count);
 170
 171 void elf_init(struct elf_params_t *params);
 172 void elf_add_load_section(struct elf_params_t *params,
 173     uint32_t load_addr, uint32_t size, const void *section);
 174 void elf_add_fill_section(struct elf_params_t *params,
 175     uint32_t fill_addr, uint32_t size, uint32_t pattern);
 176 void elf_output(struct elf_params_t *params, elf_write_fn_t write, void *user);
 177 bool elf_is_empty(struct elf_params_t *params);
 178 void elf_set_start_addr(struct elf_params_t *params, uint32_t addr);
 179 void elf_release(struct elf_params_t *params);