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[nasm:elf] output: Elf -- Start using ElfX_Ehdr instead of opencoded writes
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From: nasm-bot f. C. G. <gor...@gm...> - 2017-03-12 21:39:23
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Commit-ID: 98b28cb3ff8877bb7a37d794160f3fdfa23e7cb1 Gitweb: http://repo.or.cz/w/nasm.git?a=commitdiff;h=98b28cb3ff8877bb7a37d794160f3fdfa23e7cb1 Author: Cyrill Gorcunov <gor...@gm...> AuthorDate: Wed, 8 Mar 2017 16:48:00 +0300 Committer: Cyrill Gorcunov <gor...@gm...> CommitDate: Sun, 12 Mar 2017 11:41:44 +0300 output: Elf -- Start using ElfX_Ehdr instead of opencoded writes This should be more convenient. At least both headers are well documented in specifications so we simply follow them. Signed-off-by: Cyrill Gorcunov <gor...@gm...> --- output/outelf.c | 90 +++++++++++++++++++++++++++++++++------------------------ 1 file changed, 52 insertions(+), 38 deletions(-) diff --git a/output/outelf.c b/output/outelf.c index 8be97b3..a4f8283 100644 --- a/output/outelf.c +++ b/output/outelf.c @@ -1610,46 +1610,60 @@ static void elf_write(void) * Output the ELF header. */ if (is_elf32() || is_elfx32()) { - nasm_write("\177ELF\1\1\1", 7, ofile); - fputc(elf_osabi, ofile); - fputc(elf_abiver, ofile); - fwritezero(7, ofile); - fwriteint16_t(ET_REL, ofile); /* relocatable file */ - fwriteint16_t(is_elf32() ? EM_386 : EM_X86_64, ofile); /* processor ID */ - fwriteint32_t(1L, ofile); /* EV_CURRENT file format version */ - fwriteint32_t(0L, ofile); /* no entry point */ - fwriteint32_t(0L, ofile); /* no program header table */ - fwriteint32_t(0x40L, ofile); /* section headers straight after ELF header plus alignment */ - fwriteint32_t(0L, ofile); /* no special flags */ - fwriteint16_t(0x34, ofile); /* size of ELF header */ - fwriteint16_t(0, ofile); /* no program header table, again */ - fwriteint16_t(0, ofile); /* still no program header table */ - fwriteint16_t(sizeof(Elf32_Shdr), ofile); /* size of section header */ - fwriteint16_t(nsections, ofile); /* number of sections */ - fwriteint16_t(sec_shstrtab, ofile); /* string table section index for section header table */ - - fwriteint32_t(0L, ofile); /* align to 0x40 bytes */ - fwriteint32_t(0L, ofile); - fwriteint32_t(0L, ofile); + Elf32_Ehdr ehdr; + + nasm_zero(&ehdr.e_ident); + memcpy(ehdr.e_ident, ELFMAG, SELFMAG); + ehdr.e_ident[EI_CLASS] = char_le(ELFCLASS32); + ehdr.e_ident[EI_DATA] = char_le(ELFDATA2LSB); + ehdr.e_ident[EI_VERSION] = char_le(EV_CURRENT); + ehdr.e_ident[EI_OSABI] = char_le(elf_osabi); + ehdr.e_ident[EI_ABIVERSION] = char_le(elf_abiver); + + ehdr.e_type = short_le(ET_REL); + ehdr.e_machine = short_le(is_elf32() ? EM_386 : EM_X86_64); + ehdr.e_version = short_le(EV_CURRENT); + ehdr.e_entry = 0; + ehdr.e_phoff = 0; + ehdr.e_shoff = sizeof(Elf64_Ehdr); + ehdr.e_flags = 0; + ehdr.e_ehsize = short_le(sizeof(Elf32_Ehdr)); + ehdr.e_phentsize = 0; + ehdr.e_phnum = 0; + ehdr.e_shentsize = short_le(sizeof(Elf32_Shdr)); + ehdr.e_shnum = short_le(nsections); + ehdr.e_shstrndx = short_le(sec_shstrtab); + + nasm_write(&ehdr, sizeof(ehdr), ofile); + fwritezero(sizeof(Elf64_Ehdr) - sizeof(Elf32_Ehdr), ofile); } else { + Elf64_Ehdr ehdr; + nasm_assert(is_elf64()); - nasm_write("\177ELF\2\1\1", 7, ofile); - fputc(elf_osabi, ofile); - fputc(elf_abiver, ofile); - fwritezero(7, ofile); - fwriteint16_t(ET_REL, ofile); /* relocatable file */ - fwriteint16_t(EM_X86_64, ofile); /* processor ID */ - fwriteint32_t(1L, ofile); /* EV_CURRENT file format version */ - fwriteint64_t(0L, ofile); /* no entry point */ - fwriteint64_t(0L, ofile); /* no program header table */ - fwriteint64_t(0x40L, ofile); /* section headers straight after ELF header plus alignment */ - fwriteint32_t(0L, ofile); /* no special flags */ - fwriteint16_t(0x40, ofile); /* size of ELF header */ - fwriteint16_t(0, ofile); /* no program header table, again */ - fwriteint16_t(0, ofile); /* still no program header table */ - fwriteint16_t(sizeof(Elf64_Shdr), ofile); /* size of section header */ - fwriteint16_t(nsections, ofile); /* number of sections */ - fwriteint16_t(sec_shstrtab, ofile); /* string table section index for section header table */ + + nasm_zero(&ehdr.e_ident); + memcpy(ehdr.e_ident, ELFMAG, SELFMAG); + ehdr.e_ident[EI_CLASS] = char_le(ELFCLASS64); + ehdr.e_ident[EI_DATA] = char_le(ELFDATA2LSB); + ehdr.e_ident[EI_VERSION] = char_le(EV_CURRENT); + ehdr.e_ident[EI_OSABI] = char_le(elf_osabi); + ehdr.e_ident[EI_ABIVERSION] = char_le(elf_abiver); + + ehdr.e_type = short_le(ET_REL); + ehdr.e_machine = short_le(EM_X86_64); + ehdr.e_version = short_le(EV_CURRENT); + ehdr.e_entry = 0; + ehdr.e_phoff = 0; + ehdr.e_shoff = sizeof(Elf64_Ehdr); + ehdr.e_flags = 0; + ehdr.e_ehsize = short_le(sizeof(Elf64_Ehdr)); + ehdr.e_phentsize = 0; + ehdr.e_phnum = 0; + ehdr.e_shentsize = short_le(sizeof(Elf64_Shdr)); + ehdr.e_shnum = short_le(nsections); + ehdr.e_shstrndx = short_le(sec_shstrtab); + + nasm_write(&ehdr, sizeof(ehdr), ofile); } /* |
