diff options
Diffstat (limited to 'src/elf_format.h')
| -rw-r--r-- | src/elf_format.h | 156 |
1 files changed, 140 insertions, 16 deletions
diff --git a/src/elf_format.h b/src/elf_format.h index b5a268a..c60ac64 100644 --- a/src/elf_format.h +++ b/src/elf_format.h @@ -12,6 +12,7 @@ constexpr size_t kIdentSize = 16; constexpr size_t kHeaderSize = kIdentSize + 36; constexpr size_t kMagicSize = 4; constexpr size_t kProgramHeaderSize = 32; +constexpr size_t kSectionHeaderSize = 40; using Address = uint32_t; using Offset = uint32_t; @@ -143,6 +144,13 @@ enum class Machine : uint16_t { kUnknown, }; +static constexpr inline uint8_t ParseU8(const uint8_t *d) { return *d; } + +static constexpr inline uint8_t ParseU8(const uint8_t *d, DataEncoding) +{ + return ParseU8(d); +} + static constexpr inline uint16_t ParseU16(const uint8_t *d, DataEncoding e) { if (e == DataEncoding::k2MSB) { @@ -194,15 +202,15 @@ struct Header32Raw { uint16_t machine; uint32_t version; Address entry; - Offset phoff; - Offset shoff; + Offset phoff; ///< Program header table's file offset in bytes + Offset shoff; ///< Section header table's file offset in bytes uint32_t flags; - uint16_t ehsize; + uint16_t ehsize; ///< ELF's header size in bytes uint16_t phentsize; uint16_t phnum; uint16_t shentsize; uint16_t shnum; - uint16_t shstrndx; + uint16_t shstrndx; ///< Index of .strtab in section header table static constexpr inline auto FromBytes(const uint8_t *data) { const auto ident = Ident32Raw::FromBytes(data); @@ -232,15 +240,15 @@ struct Header32 { Machine machine; Version version; Address entry; - Offset phoff; - Offset shoff; + Offset phoff; ///< Program header table's file offset in bytes + Offset shoff; ///< Section header table's file offset in bytes uint32_t flags; - uint16_t ehsize; + uint16_t ehsize; ///< ELF's header size in bytes uint16_t phentsize; uint16_t phnum; uint16_t shentsize; uint16_t shnum; - uint16_t shstrndx; + uint16_t shstrndx; ///< Index of .strtab in section header table static constexpr inline auto FromBytes(const uint8_t *data) { const auto raw = Header32Raw::FromBytes(data); @@ -308,14 +316,130 @@ struct ProgramHeader32 { static constexpr inline auto FromBytes(const uint8_t *data, const DataEncoding e) { return ProgramHeader32{ - /* type */ ParseU32(data + 0, e), - /* offset */ ParseU32(data + 4, e), - /* vaddr */ ParseU32(data + 8, e), - /* paddr */ ParseU32(data + 12, e), - /* filesz */ ParseU32(data + 16, e), - /* memsz */ ParseU32(data + 20, e), - /* flags */ ParseU32(data + 24, e), - /* align */ ParseU32(data + 28, e), + /* .type = */ ParseU32(data + 0, e), + /* .offset = */ ParseU32(data + 4, e), + /* .vaddr = */ ParseU32(data + 8, e), + /* .paddr = */ ParseU32(data + 12, e), + /* .filesz = */ ParseU32(data + 16, e), + /* .memsz = */ ParseU32(data + 20, e), + /* .flags = */ ParseU32(data + 24, e), + /* .align = */ ParseU32(data + 28, e), + }; + } +}; + +enum class SectionHeader32Type: uint32_t { + kNull = 0, + kProgBits = 1, + kSymtab = 2, + kStrtab = 3, + kRela = 4, + kHash = 5, + kDynamic = 6, + kNote = 7, + kNobits = 8, + kRel = 9, + kShlib = 10, + kDynsym = 11, + kLoProc = 0x70000000, + kHiProc = 0x7fffffff, + kLoUser = 0x80000000, + kHiUser = 0xffffffff, +}; + +struct SectionHeader32 { + uint32_t name{}; + uint32_t type{}; + uint32_t flags{}; + Address addr{}; + Offset offset{}; + uint32_t size{}; ///< Size of whole section in bytes + uint32_t link{}; + uint32_t info{}; + uint32_t addralign{}; + uint32_t entsize{}; ///< Size of a single entry (every entry has same size) + static constexpr inline auto FromBytes(const uint8_t *data, const DataEncoding e) + { + return SectionHeader32{ + /* .name = */ ParseU32(data + 0, e), + /* .type = */ ParseU32(data + 4, e), + /* .flags = */ ParseU32(data + 8, e), + /* .addr = */ ParseU32(data + 12, e), + /* .offset = */ ParseU32(data + 16, e), + /* .size = */ ParseU32(data + 20, e), + /* .link = */ ParseU32(data + 24, e), + /* .info = */ ParseU32(data + 28, e), + /* .addralign = */ ParseU32(data + 32, e), + /* .entsize = */ ParseU32(data + 36, e), + }; + } + constexpr bool IsValid(void) const { return name != 0; } +}; + +enum class Symbol32Bind: unsigned char { + kLocal = 0, + kGlobal = 1, + kWeak = 2, + kUnknown3 = 3, + kUnknown4 = 4, + kUnknown5 = 5, + kUnknown6 = 6, + kUnknown7 = 7, + kUnknown8 = 8, + kUnknown9 = 9, + kUnknown10 = 10, + kUnknown11 = 11, + kUnknown12 = 12, + kLoProc = 13, + kUnknown14 = 14, + kHiProc = 15, +}; + +enum class Symbol32Type: unsigned char { + kNoType = 0, + kObject = 1, + kFunc = 2, + kSection = 3, + kFile = 4, + kUnknown5 = 5, + kUnknown6 = 6, + kUnknown7 = 7, + kUnknown8 = 8, + kUnknown9 = 9, + kUnknown10 = 10, + kUnknown11 = 11, + kUnknown12 = 12, + kLoProc = 13, + kUnknown14 = 14, + kHiProc = 15, +}; + +struct Symbol32 { + const char *name{}; + uint32_t namendx{}; + Address value{}; ///< Value or address, e.g address of a variable in RAM + uint32_t size{}; ///< Size of a symbol, e.g length of a function, etc. + unsigned char info{}; + unsigned char other{}; + uint16_t shndx{}; ///< Index of a section the symbol belongs to + constexpr Symbol32Bind bind() const + { + return static_cast<Symbol32Bind>(info >> 4); + } + constexpr Symbol32Type type() const + { + return static_cast<Symbol32Type>(info & 0xf); + } + static constexpr inline auto FromBytes(const uint8_t *data, const DataEncoding e) + { + return Symbol32{ + /* .name = */ nullptr, + /* .namendx = */ ParseU32(data + 0, e), + /* .value = */ ParseU32(data + 4, e), + /* .size = */ ParseU32(data + 8, e), + /* .info = */ ParseU8(data + 12, e), + /* .other = */ ParseU8(data + 13, e), + /* .shndx = */ ParseU16(data + 14, e), }; } }; |