From c7217fa43806228ff46af1e21242ce4dd82a06a6 Mon Sep 17 00:00:00 2001 From: "Anthony G. Basile" Date: Mon, 5 Jan 2015 11:24:44 -0500 Subject: misc/elf-abi: code cleanup --- misc/elf-abi/elf-abi.c | 281 +++++++++++++++++++++++-------------------------- 1 file changed, 130 insertions(+), 151 deletions(-) diff --git a/misc/elf-abi/elf-abi.c b/misc/elf-abi/elf-abi.c index aa383c4..6b3a9c2 100644 --- a/misc/elf-abi/elf-abi.c +++ b/misc/elf-abi/elf-abi.c @@ -7,15 +7,15 @@ * * Supported identifiers: * - * alpha_32 - * arm_{oabi32,32,64} - * hppa_32,64 - * ia_64 - * m68k_32 + * alpha_{32,64} + * arm_{32,64} + * hppa_{32,64} + * ia_{32,64} + * m68k_{32,64} * mips_{n32,n64,o32} * ppc_{32,64} - * s390_32 - * sh_32 + * s390_{32,64} + * sh_{32,64} * sparc_{32,64} * x86_{32,x32,64} * @@ -35,7 +35,6 @@ * * http://www.sco.com/developers/gabi/2000-07-17/ch4.eheader.html * - * * Copyright 2015 Anthony G. Basile - * Copyright 2015 Zac Medico - * @@ -102,64 +101,91 @@ E_MIPS_ABI_EABI64 = 0x00004000 #define EF_ARM_NEW_ABI 0x80 #define EF_ARM_OLD_ABI 0x100 -/* -def compute_suffix_mips(elf_header): - name = None - mips_abi = elf_header.e_flags & EF_MIPS_ABI - if mips_abi: - if mips_abi == E_MIPS_ABI_O32: - name = "o32" - elif mips_abi == E_MIPS_ABI_O64: - name = "o64" - elif mips_abi == E_MIPS_ABI_EABI32: - name = "eabi32" - elif mips_abi == E_MIPS_ABI_EABI64: - name = "eabi64" - - elif elf_header.e_flags & EF_MIPS_ABI2: - name = "n32" - elif elf_header.ei_class == ELFCLASS64: - name = "n64" - return name - -def compute_multilib_id(elf_header): - prefix = machine_prefix_map.get(elf_header.e_machine) - suffix = None +int +get_wordsize(uint8_t ei_class) +{ + switch (ei_class) { + case ELFCLASS32: + return 32; + case ELFCLASS64: + return 64; + default: + return 0; + } +} - if prefix == "mips": - suffix = compute_suffix_mips(elf_header) - elif elf_header.ei_class == ELFCLASS64: - suffix = "64" - elif elf_header.ei_class == ELFCLASS32: - if elf_header.e_machine == EM_X86_64: - suffix = "x32" - else: - suffix = "32" - if prefix is None or suffix is None: - multilib_id = None - else: - multilib_id = "%s_%s" % (prefix, suffix) +int +get_endian(uint8_t ei_data) +{ + switch (ei_data) { + case ELFDATA2LSB: + return -1; + case ELFDATA2MSB: + return 1; + default: + return 0; + } +} - return multilib_id -*/ -#define MAX_IDENT 32 +char * +get_abi(uint16_t e_machine, int width, uint32_t e_flags) +{ + switch(e_machine) { + case EM_ALPHA: + case EM_FAKE_ALPHA: + return "alpha"; + case EM_X86_64: + return "amd64"; + case EM_ARM: + return "arm"; + case EM_AARCH64: + return "arm64"; + case EM_68K: + return "m68k"; + case EM_MIPS_RS3_LE: + case EM_MIPS: + return "mips"; + case EM_IA_64: + return "ia64"; + case EM_PARISC: + return "hppa"; + case EM_PPC: + return "ppc"; + case EM_PPC64: + return "ppc64"; + case EM_S390: + return "s390"; + case EM_SH: + return "sh"; + case EM_SPARC32PLUS: + case EM_SPARCV9: + case EM_SPARC: + return "sparc"; + case EM_386: + return "x86"; + default: + return "unknown_arch"; + } +} int main(int argc, char* argv[]) { - char ident[MAX_IDENT]; /* The Gentoo standard arch_abi identifier. */ - char *arch; /* The Gentoo architecture identifier. */ - int fd; - struct stat s; + int width; /* Machine word size. Either 32 or 64 bits. */ + int endian; /* Endian, -1 = little, 1 = big */ + char *abi; /* Abi name from glibc's */ + + int fd; /* file descriptor for opened Elf object. */ + struct stat s; /* stat on opened Elf object. */ char magic[4]; /* magic number at the begining of the file */ - uint8_t ei_class, width; /* width = 8 bytes for 32-bits, 16 bytes for 64-bits. */ - uint8_t ei_data, endian; /* endian = 0 for little, 1 for big endian. */ + uint8_t ei_class; /* ei_class is one byte of e_ident[] */ + uint8_t ei_data; /* ei_data is one byte of e_ident[] */ uint16_t e_machine; /* Size is Elf32_Half or Elf64_Half. Both are 2 bytes. */ uint32_t e_flags; /* Size is Elf32_Word or Elf64_Word. Both are 4 bytes. */ - uint64_t e_flags_offset; /* Wide enough for either 32 or 64 bits. */ + uint64_t e_machine_offset, e_flags_offset; /* Wide enough for either 32 or 64 bits. */ /* Is the second parameter a regular file? */ if (argc != 2) @@ -177,120 +203,73 @@ main(int argc, char* argv[]) if (strncmp(magic, ELFMAG, 4) != 0) errx(1, "%s is not an ELF object", argv[1]); - /* 32 or 64 bits? */ if (read(fd, &ei_class, 1) == -1) err(1, "read() ei_class failed"); - switch (ei_class) { - case ELFCLASS32: - width = 4; - printf("32 bit\n"); - break; - case ELFCLASS64: - width = 8; - printf("64 bit\n"); - break; - default: - width = 0; - printf("Unknown bit\n"); - } + width = get_wordsize(ei_class); /* Little or Big Endian? */ if (read(fd, &ei_data, 1) == -1) err(1, "read() ei_data failed"); - switch (ei_data) { - case ELFDATA2LSB: - endian = 0; - printf("Little Endian\n"); - break; - case ELFDATA2MSB: - endian = 1; - printf("Big Endian\n"); - break; - default: - endian = -1; - printf("Unknown Endian\n"); - } + endian = get_endian(ei_data); - /* Seek to e_macine = 16 bytes (e_ident[])) + 2 bytes (e_type which is Elf32_Half/Elf64_Half) */ - if (lseek(fd, 18, SEEK_SET) == -1) - err(1, "lseek() e_machine failed"); + /* + All Elf files begin with the following Elf header: + unsigned char e_ident[EI_NIDENT]; - 16 bytes + Elf32_Half e_type; - 2 bytes + Elf32_Half e_machine; - 2 bytes + Elf32_Word e_version; - 4 bytes + Elf32_Addr e_entry; - 4 bytes or 8 bytes for Elf64 + Elf32_Off e_phoff; - 4 bytes or 8 bytes for Elf64 + Elf32_Off e_shoff; - 4 bytes or 8 bytes for Elf64 + Elf32_Word e_flags; - 4 bytes + + Seek to e_machine = 18 bytes. + Seek to e_flags = 36 bytes (Elf32) or 48 bytes (Elf64) + */ + e_machine_offset = 18; + if (width == 32) + e_flags_offset = 36; + else + e_flags_offset = 48; - /* What is the arch? */ + /* What is the abi? */ + if (lseek(fd, e_machine_offset, SEEK_SET) == -1) + err(1, "lseek() e_machine failed"); if (read(fd, &e_machine, 2) == -1) err(1, "read() e_machine failed"); - switch(e_machine) { - case EM_ALPHA: - case EM_FAKE_ALPHA: - arch = "alpha"; - break; - case EM_X86_64: - arch = "amd64"; - break; - case EM_ARM: - arch = "arm"; - break; - case EM_AARCH64: - arch = "arm64"; - break; - case EM_68K: - arch = "m68k"; - break; - case EM_MIPS_RS3_LE: - case EM_MIPS: - arch = "mips"; - break; - case EM_IA_64: - arch = "ia64"; - break; - case EM_PARISC: - arch = "hppa"; - break; - case EM_PPC: - arch = "ppc"; - break; - case EM_PPC64: - arch = "ppc64"; - break; - case EM_S390: - arch = "s390"; - break; - case EM_SH: - arch = "sh"; - break; - case EM_SPARC32PLUS: - case EM_SPARCV9: - case EM_SPARC: - arch = "sparc"; - break; - case EM_386: - arch = "x86"; - break; - default: - arch = "unknown"; - } - printf("%s\n", arch); - /* - e_data_offset = - if (lseek(fd, 18, SEEK_SET) == -1) - err(1, "lseek() e_machine failed"); + if (lseek(fd, e_flags_offset, SEEK_SET) == -1) + err(1, "lseek() e_flags failed"); if (read(fd, &e_flags, 2) == -1) - err(1, "read() e_machine failed"); - */ - /* - # E_ENTRY + 3 * sizeof(uintN) - e_flags_offset = E_ENTRY + 3 * width // 8 - f.seek(e_flags_offset) - e_flags = uint32(f.read(4)) + err(1, "read() e_flags failed"); - return _elf_header(ei_class, ei_data, e_machine, e_flags) + abi = get_abi(e_machine, width, e_flags); - multilib_id = compute_multilib_id(elf_header) - */ + printf("%s\n", abi); - memset(ident, 0, MAX_IDENT); +/* + if (!strcmp(arch, "mips")) ; + switch (e_flags & EF_MIPS_ABI) { + case E_MIPS_ABI_O32: + abi = "o32"; + break; + + if mips_abi == E_MIPS_ABI_O32: + name = "o32" + elif mips_abi == E_MIPS_ABI_O64: + name = "o64" + elif mips_abi == E_MIPS_ABI_EABI32: + name = "eabi32" + elif mips_abi == E_MIPS_ABI_EABI64: + name = "eabi64" + elif elf_header.e_flags & EF_MIPS_ABI2: + name = "n32" + elif elf_header.ei_class == ELFCLASS64: + name = "n64" + } +*/ close(fd); exit(EXIT_SUCCESS); } -- cgit v1.2.3-65-gdbad